DIgSILENT PF 15.1.2 manual

DIG

SILENT

I N T E G R AT E D P O W E R S Y S T E M A N A LY S I S S O F T W A R E

DIgSILENT

PowerFactory 15 User Manual

PowerFactory

DIgSILENT PowerFactory Version 15.1

User Manual

Online Edition DIgSILENT GmbH Gomaringen, Germany December 2013

Publisher: DIgSILENT GmbH Heinrich-Hertz-Straße 9 72810 Gomaringen / Germany Tel.: +49 (0) 7072-9168-0 Fax: +49 (0) 7072-9168-88

Please visit our homepage at: http://www.digsilent.de

Copyright DIgSILENT GmbH All rights reserved. No part of this publication may be reproduced or distributed in any form without permission of the publisher. December 2013 r1181

Contents I

General Information

1 About this Guide

1 3

1.1

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3

1.2

Contents of the User Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3

1.3

Used Conventions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

3

2 Contact

5

2.1

Direct Technical Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

5

2.2

General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

6

3 Documentation and Help System

7

4 PowerFactory Overview

9

4.1

General Concept . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

4.2

Database, Objects, and Classes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

4.3

PowerFactory Simulation Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

4.4

General Design of PowerFactory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

4.5

Type and Element Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

4.6

Data Arrangement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 4.6.1

Global Library . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

4.6.2

Project Library . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

4.6.3

Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

4.6.4

Network Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

4.6.5

Operation Scenarios . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

4.6.6

Study Cases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

4.6.7

Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

DIgSILENT PowerFactory 15, User Manual

i

CONTENTS 4.7

4.8

4.9

II

Project Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18 4.7.1

Nodes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

4.7.2

Branches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

4.7.3

Cubicles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

4.7.4

Switches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

4.7.5

Substations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

4.7.6

Sites . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

4.7.7

Branch Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

User Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 4.8.1

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

4.8.2

Menu Bar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

4.8.3

Main Toolbar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

4.8.4

The Output Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

DIgSILENT Programming Language (DPL) Scripts . . . . . . . . . . . . . . . . . . . . . . 28

Administration

5 Program Administration

33

5.1

Program Installation and Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

5.2

The SetConfig Dialogue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

5.3

5.4

ii

31

5.2.1

General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

5.2.2

Database . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

5.2.3

License . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

5.2.4

Workspace . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

5.2.5

External Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

5.2.6

Advanced Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

Workspace options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 5.3.1

Show Workspace Directory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

5.3.2

Import and Export Workspace . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

5.3.3

Show Default Export Directory

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

Offline Mode User Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 5.4.1

Functionality in Offline mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36

5.4.2

Functionality in Online mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 DIgSILENT PowerFactory 15, User Manual

CONTENTS 5.4.3 5.5

Terminate Offline session . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Housekeeping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40 5.5.1

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

5.5.2

Configuring permanently logged-on users . . . . . . . . . . . . . . . . . . . . . . 41

5.5.3

Configuring housekeeping tasks . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

5.5.4

Configuring deletion of old projects . . . . . . . . . . . . . . . . . . . . . . . . . . 42

5.5.5

Configuring purging of projects . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

5.5.6

Configuring emptying of recycle bins . . . . . . . . . . . . . . . . . . . . . . . . . 44

5.5.7

Monitoring Housekeeping . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

5.5.8

Summary of Housekeeping Deployment . . . . . . . . . . . . . . . . . . . . . . . 44

6 User Accounts, User Groups, and Profiles

45

6.1

PowerFactory Database Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

6.2

The Database Administrator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

6.3

Creating and Managing User Accounts . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

6.4

Creating User Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47

6.5

Creating Profiles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 6.5.1

Tool Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

6.5.2

Configuration of Toolbars

6.5.3

Configuration of Menus

6.5.4

Configuration of Dialogue Pages . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

6.5.5

Configuration of Dialogue Parameters . . . . . . . . . . . . . . . . . . . . . . . . 53

6.5.6

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 52

7 User Settings

55

7.1

General Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

7.2

Graphic Windows Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

7.3

Data Manager Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

7.4

Output Window Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

7.5

Functions Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

7.6

Directories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

7.7

Editor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

7.8

StationWare . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59

DIgSILENT PowerFactory 15, User Manual

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CONTENTS 7.9

III

Advanced Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60

Handling

61

8 Basic Project Definition 8.1

8.2

Defining and Configuring a Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 8.1.1

The Project Edit Dialogue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

8.1.2

The Project Overview Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

8.1.3

Project Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

8.1.4

Activating and Deactivating Projects . . . . . . . . . . . . . . . . . . . . . . . . . 69

8.1.5

Exporting and Importing of Projects . . . . . . . . . . . . . . . . . . . . . . . . . . 69

8.1.6

External References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

Creating New Grids . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

9 Network Graphics (Single Line Diagrams)

71

9.1

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

9.2

Defining Network Models with the Graphical Editor . . . . . . . . . . . . . . . . . . . . . . 71

9.3

9.2.1

Adding New Power System Elements . . . . . . . . . . . . . . . . . . . . . . . . . 71

9.2.2

Drawing Nodes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

9.2.3

Drawing Branch Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

9.2.4

Marking and Editing Power System Elements . . . . . . . . . . . . . . . . . . . . 74

9.2.5

Interconnecting Power Subsystems . . . . . . . . . . . . . . . . . . . . . . . . . . 76

9.2.6

Working with Substations in the Graphical Editor . . . . . . . . . . . . . . . . . . 77

9.2.7

Working with Composite Branches in the Graphical Editor . . . . . . . . . . . . . 81

9.2.8

Working with Single and Two Phase Elements . . . . . . . . . . . . . . . . . . . . 81

Defining and Working with Lines and Cables . . . . . . . . . . . . . . . . . . . . . . . . . 82 9.3.1

Defining a Line (ElmLne) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

9.3.2

Defining Line Sections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

9.3.3

Example Cable System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 84

9.3.4

Example Line Couplings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86

9.4

Neutral winding connection in network diagrams . . . . . . . . . . . . . . . . . . . . . . . 87

9.5

Graphic Windows and Database Objects . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 9.5.1

iv

63

Network Diagrams and Graphical Pages . . . . . . . . . . . . . . . . . . . . . . . 90

DIgSILENT PowerFactory 15, User Manual

CONTENTS 9.5.2

Active Graphics, Graphics Board and Study Cases . . . . . . . . . . . . . . . . . 91

9.5.3

Single Line Graphics and Data Objects . . . . . . . . . . . . . . . . . . . . . . . . 92

9.5.4

Editing and Selecting Objects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93

9.5.5

Creating a New Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94

9.5.6

Creating New Graphic Windows . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94

9.5.7

Basic Functionality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95

9.5.8

Page Tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95

9.5.9

Drawing Toolboxes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95

9.5.10 Active Grid Folder (Target Folder) . . . . . . . . . . . . . . . . . . . . . . . . . . . 96 9.6

9.7

Drawing Diagrams with Existing Network Elements . . . . . . . . . . . . . . . . . . . . . 96 9.6.1

Drawing Existing Busbars . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97

9.6.2

Drawing Existing Lines, Switches, and Transformers . . . . . . . . . . . . . . . . 98

9.6.3

Building Single Line Diagrams from Imported Data . . . . . . . . . . . . . . . . . 98

Graphic Commands, Options, and Settings . . . . . . . . . . . . . . . . . . . . . . . . . . 99 9.7.1

Zoom, Pan, and Select Commands . . . . . . . . . . . . . . . . . . . . . . . . . . 100

9.7.2

Page, Graphic, and Print Options . . . . . . . . . . . . . . . . . . . . . . . . . . . 102

9.7.3

Graphic Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104

9.7.4

Layers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106

9.7.5

Element Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110

9.7.6

Graphic Attributes and Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113

9.7.7

Node Default Options

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 117

9.8

Editing and Changing Symbols of Elements . . . . . . . . . . . . . . . . . . . . . . . . . . 117

9.9

Results Boxes, Text Boxes and Labels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118 9.9.1

Results Boxes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118

9.9.2

Text Boxes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120

9.9.3

Labels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120

9.9.4

Free Text Labels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120

9.10 Annotation Layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121 9.11 Annotation of protection device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123 9.12 Geographical Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124 10 Data Manager

127

10.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127 DIgSILENT PowerFactory 15, User Manual

v

CONTENTS 10.2 Using the Data Manager . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127 10.2.1 Navigating the Database Tree . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 129 10.2.2 Adding New Items . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130 10.2.3 Deleting an Item . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131 10.2.4 Cut, Copy, Paste and Move Objects . . . . . . . . . . . . . . . . . . . . . . . . . . 132 10.2.5 The Data Manager Message Bar . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 10.2.6 Additional Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 133 10.3 Defining Network Models with the Data Manager . . . . . . . . . . . . . . . . . . . . . . . 134 10.3.1 Defining New Network Components in the Data Manager . . . . . . . . . . . . . 134 10.3.2 Connecting Network Components in the Data Manager . . . . . . . . . . . . . . . 134 10.3.3 Defining Substations in the Data Manager . . . . . . . . . . . . . . . . . . . . . . 134 10.3.4 Defining Composite Branches in the Data Manager . . . . . . . . . . . . . . . . . 135 10.3.5 Defining Sites in the Data Manager . . . . . . . . . . . . . . . . . . . . . . . . . . 136 10.3.6 Editing Network Components using the Data Manager . . . . . . . . . . . . . . . 136 10.4 Searching for Objects in the Data Manager . . . . . . . . . . . . . . . . . . . . . . . . . . 137 10.4.1 Sorting Objects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137 10.4.2 Searching by Name

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137

10.4.3 Using Filters for Search . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138 10.5 Editing Data Objects in the Data Manager . . . . . . . . . . . . . . . . . . . . . . . . . . . 140 10.5.1 Editing in Object Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141 10.5.2 Editing in "Detail" Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142 10.5.3 Copy and Paste while Editing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 144 10.6 The Flexible Data Page Tab in the Data Manager

. . . . . . . . . . . . . . . . . . . . . . 145

10.6.1 Customizing the Flexible Data Page . . . . . . . . . . . . . . . . . . . . . . . . . 145 10.7 The Input Window in the Data Manager . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147 10.7.1 Input Window Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147 10.8 Save and Restore Parts of the Database . . . . . . . . . . . . . . . . . . . . . . . . . . . 148 10.8.1 Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 149 10.9 Spreadsheet Format Data Import/Export . . . . . . . . . . . . . . . . . . . . . . . . . . . 149 10.9.1 Export to Spreadsheet Programs (e. g. MS EXCEL) . . . . . . . . . . . . . . . . 149 10.9.2 Import from Spreadsheet Programs (e. g. MS EXCEL) . . . . . . . . . . . . . . . 151 11 Study Cases vi

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CONTENTS 11.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 157 11.2 Creating and Using Study Cases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158 11.3 Summary Grid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159 11.4 Study Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 159 11.5 The Study Case Edit Dialogue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160 11.6 Variation Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161 11.7 Operation Scenarios . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161 11.8 Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161 11.9 Events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162 11.9.1 Dispatch Event . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163 11.9.2 External Measurement Event . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163 11.9.3 Intercircuit Fault Events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163 11.9.4 Events of Loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163 11.9.5 Message Event . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163 11.9.6 Outage of Element . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 163 11.9.7 Parameter Events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164 11.9.8 Save Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164 11.9.9 Short-Circuit Events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164 11.9.10 Stop Events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164 11.9.11 Switch Events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164 11.9.12 Synchronous Machine Event . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165 11.9.13 Tap Event . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165 11.10Simulation Scan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165 11.11Results Objects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 165 11.12Variable Sets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167 11.13Triggers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 167 11.14Graphic Board . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 168 12 Project Library

169

12.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169 12.2 Equipment Type Library . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169 12.3 Operational Library . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171 12.3.1 Circuit Breaker Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171 DIgSILENT PowerFactory 15, User Manual

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CONTENTS 12.3.2 Demand Transfers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173 12.3.3 Fault Cases and Fault Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173 12.3.4 Capability Curves (Mvar Limit Curves) for Generators . . . . . . . . . . . . . . . . 177 12.3.5 Planned Outages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178 12.3.6 Running Arrangements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180 12.3.7 Thermal Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 183 12.4 Templates Library . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184 12.4.1 General Templates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185 12.4.2 Substation Templates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185 12.4.3 Busbar Templates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185 12.4.4 Composite Branch Templates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185 12.4.5 Example Generator Template . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186 12.4.6 Example Busbar Template . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 186 13 Grouping Objects

189

13.1 Areas . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189 13.2 Virtual Power Plants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 189 13.2.1 Defining and Editing a New Virtual Power Plant . . . . . . . . . . . . . . . . . . . 190 13.2.2 Applying a Virtual Power Plant

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 191

13.2.3 Inserting a Generator into a Virtual Power Plant and Defining its Virtual Power Plant Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191 13.3 Boundaries . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192 13.4 Circuits (ElmCircuit) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 193 13.5 Feeders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 194 13.6 Operators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196 13.7 Owners . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197 13.8 Paths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197 13.9 Routes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198 13.10Zones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 198 14 Operation Scenarios

199

14.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199 14.2 Operation Scenarios Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199 14.3 How to use Operation Scenarios . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200 viii

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CONTENTS 14.3.1 How to create an Operation Scenario . . . . . . . . . . . . . . . . . . . . . . . . . 201 14.3.2 How to save an Operation Scenario . . . . . . . . . . . . . . . . . . . . . . . . . . 202 14.3.3 How to activate an existing Operation Scenario . . . . . . . . . . . . . . . . . . . 203 14.3.4 How to deactivate an Operation Scenario . . . . . . . . . . . . . . . . . . . . . . 203 14.3.5 How to identify operational data parameters . . . . . . . . . . . . . . . . . . . . . 204 14.4 Administering Operation Scenarios . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 205 14.4.1 How to view objects missing from the Operation Scenario data . . . . . . . . . . 205 14.4.2 How to compare the data in two operation scenarios . . . . . . . . . . . . . . . . 205 14.4.3 How to view the non-default Running Arrangements . . . . . . . . . . . . . . . . 206 14.4.4 How to transfer data from one Operation Scenario to another . . . . . . . . . . . 206 14.4.5 How to update the default data with operation scenario data . . . . . . . . . . . . 207 14.4.6 How exclude a grid from the Operation Scenario data

. . . . . . . . . . . . . . . 207

14.4.7 How to create a time based Operation Scenario . . . . . . . . . . . . . . . . . . . 207 14.5 Advanced Configuration of Operation Scenarios . . . . . . . . . . . . . . . . . . . . . . . 209 14.5.1 How to change the automatic save settings for Operation Scenarios . . . . . . . 209 14.5.2 How to modify the data stored in Operation Scenarios . . . . . . . . . . . . . . . 209 15 Network Variations and Expansion Stages

211

15.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 211 15.2 Variations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 212 15.3 Expansion Stages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213 15.4 The Study Time . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213 15.5 The Recording Expansion Stage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214 15.6 The Variation Scheduler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 214 15.7 Variation and Expansion Stage Example . . . . . . . . . . . . . . . . . . . . . . . . . . . 215 15.8 Variation and Expansion Stage Housekeeping . . . . . . . . . . . . . . . . . . . . . . . . 216 15.8.1 Applying Changes from Expansion Stages . . . . . . . . . . . . . . . . . . . . . . 216 15.8.2 Consolidating Variations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216 15.8.3 Splitting Expansion Stages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 217 15.8.4 Comparing Variations and Expansion Stages . . . . . . . . . . . . . . . . . . . . 217 15.8.5 Colouring Variations the Single Line Graphic . . . . . . . . . . . . . . . . . . . . . 218 15.8.6 Variation Conflicts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 218 15.8.7 Error Correction Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219 DIgSILENT PowerFactory 15, User Manual

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CONTENTS 15.9 Compatibility with Previous PowerFactory Releases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220 15.9.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220 15.9.2 Converting System Stages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 220 16 Parameter Characteristics, Load States, and Tariffs

225

16.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225 16.2 Parameter Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225 16.2.1 Time Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 228 16.2.2 Profile Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 230 16.2.3 Scalar Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 230 16.2.4 Vector Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 231 16.2.5 Matrix Parameter Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . 232 16.2.6 Parameter Characteristics from Files . . . . . . . . . . . . . . . . . . . . . . . . . 233 16.2.7 Characteristic References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233 16.2.8 Edit Characteristic Dialogue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 233 16.2.9 Browser in ’Scales’ mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 234 16.2.10 Example Application of Characteristics . . . . . . . . . . . . . . . . . . . . . . . . 235 16.3 Load States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238 16.3.1 Creating Load States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238 16.3.2 Viewing Existing Load States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 238 16.3.3 Load State Object Properties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239 16.3.4 Example Load States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 239 16.4 Load Distribution States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 241 16.4.1 Creating Load Distribution States . . . . . . . . . . . . . . . . . . . . . . . . . . . 241 16.4.2 Viewing Existing Load Distribution States . . . . . . . . . . . . . . . . . . . . . . 242 16.4.3 Load Distribution State Object Properties . . . . . . . . . . . . . . . . . . . . . . 242 16.4.4 Example Load Distribution States . . . . . . . . . . . . . . . . . . . . . . . . . . . 242 16.5 Tariffs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244 16.5.1 Defining Time Tariffs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244 16.5.2 Defining Energy Tariffs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 245 17 Reporting and Visualizing Results

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CONTENTS 17.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247 17.2 Results, Graphs and Documentation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247 17.2.1 Editing Result Boxes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 247 17.2.2 Output of Device Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250 17.2.3 Output of Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 252 17.2.4 Result Objects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 253 17.3 Comparisons Between Calculations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 256 17.3.1 Editing a Set Of Comparison Cases . . . . . . . . . . . . . . . . . . . . . . . . . 257 17.3.2 Update Database . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 257 17.4 Variable Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 258 17.4.1 The Variable Selection Monitor Dialogue . . . . . . . . . . . . . . . . . . . . . . . 258 17.4.2 Searching the Variables to Monitor . . . . . . . . . . . . . . . . . . . . . . . . . . 260 17.4.3 Examples of Variable Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . 261 17.4.4 Selecting the Bus to be Monitored . . . . . . . . . . . . . . . . . . . . . . . . . . 265 17.5 Virtual Instruments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 266 17.5.1 Virtual Instrument Panels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 268 17.5.2 Plots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 273 17.5.3 Calculated Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 282 17.5.4 The Vector Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 284 17.5.5 The Voltage Profile Plot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 286 17.5.6 Schematic Visualization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 289 17.5.7 The Waveform Plot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 290 17.5.8 The Curve-Input Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 292 17.5.9 Embedded Graphic Windows . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 295 17.5.10 Tools for Virtual Instruments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 296 17.5.11 User-Defined Styles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 305 18 Data Management

309

18.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 309 18.2 Project Versions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 309 18.2.1 What is a Version? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 309 18.2.2 How to Create a Version . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 310 18.2.3 How to Rollback a Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 311 DIgSILENT PowerFactory 15, User Manual

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CONTENTS 18.2.4 How to Check if a Version is the base for a derived Project . . . . . . . . . . . . . 312 18.2.5 How to Delete a Version . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 313 18.3 Derived Projects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 313 18.3.1 Derived Projects Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 313 18.3.2 How to Create a Derived Project . . . . . . . . . . . . . . . . . . . . . . . . . . . 315 18.4 Comparing and Merging Projects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 316 18.4.1 Compare and Merge Tool Background . . . . . . . . . . . . . . . . . . . . . . . . 316 18.4.2 How to Merge or Compare two projects using the Compare and Merge Tool . . . 317 18.4.3 How to Merge or Compare three projects using the Compare and Merge Tool . . 318 18.4.4 Compare and Merge Tool Advanced Options . . . . . . . . . . . . . . . . . . . . 319 18.4.5 Compare and Merge Tool ’diff browser’ . . . . . . . . . . . . . . . . . . . . . . . . 320 18.5 How to update a Project . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 325 18.5.1 Updating a Derived Project from a new Version . . . . . . . . . . . . . . . . . . . 325 18.5.2 Updating a base project from a Derived Project . . . . . . . . . . . . . . . . . . . 327 18.5.3 Tips for working with the Compare and Merge Tool . . . . . . . . . . . . . . . . . 327 18.6 Sharing Projects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 327 18.7 Database archiving . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 328 19 The DIgSILENT Programming Language - DPL

329

19.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 329 19.2 The Principle Structure of a DPL Command

. . . . . . . . . . . . . . . . . . . . . . . . . 330

19.3 The DPL Command Object . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 331 19.3.1 Creating a new DPL Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . 331 19.3.2 Defining a DPL Commands Set . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332 19.3.3 Executing a DPL Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332 19.3.4 DPL Advanced Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 332 19.3.5 DPL Script Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333 19.4 The DPL Script Editor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333 19.5 The DPL Script Language . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 333 19.5.1 Variable Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 334 19.5.2 Constant parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 334 19.5.3 Assignments and Expressions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335 19.5.4 Standard Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 335 xii

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CONTENTS 19.5.5 Program Flow Instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 336 19.5.6 Input and Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 338 19.6 Access to Other Objects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 339 19.6.1 Object Variables and Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 339 19.7 Access to Locally Stored Objects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 340 19.8 Accessing the General Selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 340 19.9 Accessing External Objects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 341 19.10Remote Scripts and DPL Command Libraries

. . . . . . . . . . . . . . . . . . . . . . . . 342

19.10.1 Subroutines and Calling Conventions . . . . . . . . . . . . . . . . . . . . . . . . . 344 19.11DPL Functions and Subroutines . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 345 20 PowerFactory Interfaces

347

20.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 347 20.2 DGS Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 347 20.2.1 DGS Interface Typical Applications . . . . . . . . . . . . . . . . . . . . . . . . . . 348 20.2.2 DGS Structure (Database Schemas and File Formats) . . . . . . . . . . . . . . . 349 20.2.3 DGS Import . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 349 20.2.4 DGS Export . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 351 20.3 PSS/E File Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 352 20.3.1 Importing PSS/E Steady-State Data . . . . . . . . . . . . . . . . . . . . . . . . . 352 20.3.2 Import of PSS/E file (Dynamic Data) . . . . . . . . . . . . . . . . . . . . . . . . . 355 20.3.3 Exporting a project to a PSS/E file . . . . . . . . . . . . . . . . . . . . . . . . . . 357 20.4 NEPLAN Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 358 20.4.1 Importing NEPLAN Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 359 20.5 INTEGRAL Interface

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 361

20.5.1 Importing Integral Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 361 20.6 UCTE-DEF Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 361 20.6.1 Importing UCTE-DEF Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 361 20.6.2 Exporting UCTE-DEF Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 363 20.7 CIM Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 364 20.7.1 Importing CIM Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 364 20.7.2 Exporting CIM Data

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 365

20.8 MATLAB Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 366 DIgSILENT PowerFactory 15, User Manual

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CONTENTS 20.9 OPC Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 366 20.9.1 OPC Interface Typical Applications . . . . . . . . . . . . . . . . . . . . . . . . . . 367 20.10StationWare Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 368 20.10.1 About StationWare . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 368 20.10.2 Component Architecture . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 369 20.10.3 Fundamental Concepts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 370 20.10.4 Configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 374 20.10.5 Getting Started . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 375 20.10.6 Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 384 20.10.7 Technical Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 390 20.11API (Application Programming Interface) . . . . . . . . . . . . . . . . . . . . . . . . . . . 394 20.12Python . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 394 20.12.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 394 20.12.2 Installation of a Python Interpreter . . . . . . . . . . . . . . . . . . . . . . . . . . 395 20.12.3 The Python PowerFactory Module . . . . . . . . . . . . . . . . . . . . . . . . . . . 395 20.12.4 The Python Command Object (ComPython) . . . . . . . . . . . . . . . . . . . . . 396 20.12.5 Running PowerFactory in Engine Mode . . . . . . . . . . . . . . . . . . . . . . . . 399 20.12.6 Debugging Python Scripts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 400 20.12.7 Example of a Python Script . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 401

IV

Power System Analysis Functions

21 Load Flow Analysis

403 405

21.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 405 21.2 Technical Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 409 21.2.1 Network Representation and Calculation Methods . . . . . . . . . . . . . . . . . 409 21.2.2 Active and Reactive Power Control . . . . . . . . . . . . . . . . . . . . . . . . . . 412 21.2.3 Advanced Load Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 416 21.2.4 Temperature Dependency of Lines and Cables . . . . . . . . . . . . . . . . . . . 420 21.3 Executing Load Flow Calculations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 422 21.3.1 Basic Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 423 21.3.2 Active Power Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 424 21.3.3 Advanced Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 427 xiv

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CONTENTS 21.3.4 Iteration Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 429 21.3.5 Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 430 21.3.6 Low Voltage Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 431 21.3.7 Advanced Simulation Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 432 21.4 Result Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 432 21.4.1 Viewing Results in the Single Line Diagram . . . . . . . . . . . . . . . . . . . . . 433 21.4.2 Flexible Data Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 433 21.4.3 Predefined Report Formats (ASCII Reports) . . . . . . . . . . . . . . . . . . . . . 434 21.4.4 Diagram Colouring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 434 21.4.5 Load Flow Sign Convention . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 435 21.5 Troubleshooting Load Flow Calculation Problems . . . . . . . . . . . . . . . . . . . . . . 435 21.5.1 General Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 435 21.5.2 Data Model Problem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 436 21.5.3 Some Load Flow Calculation Messages . . . . . . . . . . . . . . . . . . . . . . . 437 21.5.4 Too many Inner Loop Iterations . . . . . . . . . . . . . . . . . . . . . . . . . . . . 438 21.5.5 Too Many Outer Loop Iterations . . . . . . . . . . . . . . . . . . . . . . . . . . . . 439 21.6 Load Flow Sensitivities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 441 21.6.1 Load Flow Sensitivities Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . 442 21.6.2 Load Flow Sensitivities Execution and Results . . . . . . . . . . . . . . . . . . . . 443 21.6.3 Technical Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 443 22 Short-Circuit Analysis

447

22.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 447 22.2 Technical Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 448 22.2.1 The IEC 60909/VDE 0102 Method . . . . . . . . . . . . . . . . . . . . . . . . . . 451 22.2.2 The ANSI Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 455 22.2.3 The Complete Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 457 22.2.4 The IEC 61363 Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 459 22.2.5 The IEC 61660 (DC) Method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 460 22.2.6 The ANSI/IEEE 946 (DC) Method . . . . . . . . . . . . . . . . . . . . . . . . . . . 462 22.3 Executing Short-Circuit Calculations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 462 22.3.1 Toolbar/Main Menu Execution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 462 22.3.2 Context-Sensitive Menu Execution . . . . . . . . . . . . . . . . . . . . . . . . . . 463 DIgSILENT PowerFactory 15, User Manual

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CONTENTS 22.3.3 Faults on Busbars/Terminals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 463 22.3.4 Faults on Lines and Branches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 464 22.3.5 Multiple Faults Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 465 22.4 Short-Circuit Calculation Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 467 22.4.1 Basic Options (All Methods) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 467 22.4.2 Verification (Except for IEC 61363, IEC 61660 and ANSI/IEEE 946) . . . . . . . . 470 22.4.3 Basic Options (IEC 60909/VDE 0102 Method) . . . . . . . . . . . . . . . . . . . . 471 22.4.4 Advanced Options (IEC 60909/VDE 0102 Method) . . . . . . . . . . . . . . . . . 472 22.4.5 Basic Options (ANSI C37 Method) . . . . . . . . . . . . . . . . . . . . . . . . . . 474 22.4.6 Advanced Options (ANSI C37 Method) . . . . . . . . . . . . . . . . . . . . . . . . 476 22.4.7 Basic Options (Complete Method) . . . . . . . . . . . . . . . . . . . . . . . . . . 477 22.4.8 Advanced Options (Complete Method) . . . . . . . . . . . . . . . . . . . . . . . . 478 22.4.9 Basic Options (IEC 61363) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 480 22.4.10 Advanced Options (IEC 61363) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 481 22.4.11 Basic Options (IEC 61660 Method) . . . . . . . . . . . . . . . . . . . . . . . . . . 481 22.4.12 Advanced Options (IEC 61660 Method) . . . . . . . . . . . . . . . . . . . . . . . 482 22.4.13 Basic Options (ANSI/IEEE 946 Method) . . . . . . . . . . . . . . . . . . . . . . . 482 22.4.14 Advanced Options (ANSI/IEEE 946 Method) . . . . . . . . . . . . . . . . . . . . . 483 22.5 Result Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 483 22.5.1 Viewing Results in the Single Line Diagram . . . . . . . . . . . . . . . . . . . . . 483 22.5.2 Flexible Data Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 484 22.5.3 Predefined Report Formats (ASCII Reports) . . . . . . . . . . . . . . . . . . . . . 484 22.5.4 Diagram Colouring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 485 23 Power Quality and Harmonics Analysis

487

23.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 487 23.2 Harmonic Load Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 488 23.2.1 Basic Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 488 23.2.2 IEC 61000-3-6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 490 23.2.3 Advanced Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 490 23.3 Frequency Sweep . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 490 23.3.1 Basic Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 491 23.3.2 Advanced Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 491 xvi

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CONTENTS 23.4 Filter Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 492 23.5 Modelling Harmonic Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 494 23.5.1 Definition of Harmonic Injections . . . . . . . . . . . . . . . . . . . . . . . . . . . 494 23.5.2 Assignment of Harmonic Injections . . . . . . . . . . . . . . . . . . . . . . . . . . 501 23.5.3 Harmonic Distortion Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 502 23.5.4 Frequency Dependent Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . 503 23.5.5 Waveform Plot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 506 23.6 Flicker Analysis (IEC 61400-21) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 507 23.6.1 Continuous Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 508 23.6.2 Switching Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 508 23.6.3 Flicker Contribution of Wind Turbine Generator Models . . . . . . . . . . . . . . . 509 23.6.4 Definition of Flicker Coefficients . . . . . . . . . . . . . . . . . . . . . . . . . . . . 509 23.6.5 Assignment of Flicker Coefficients . . . . . . . . . . . . . . . . . . . . . . . . . . 510 23.6.6 Flicker Result Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 511 23.7 Short-Circuit Power Sk . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 511 23.7.1 Balanced Harmonic Load Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . 512 23.7.2 Unbalanced Harmonic Load Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . 512 23.7.3 Sk Result Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 512 23.7.4 Short-Circuit Power of the External Grid . . . . . . . . . . . . . . . . . . . . . . . 513 23.8 Connection Request . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 513 23.8.1 Connection Request Assessment: D-A-CH-CZ . . . . . . . . . . . . . . . . . . . 513 23.8.2 Connection Request Element . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 514 23.8.3 Connection Request Assessment Report . . . . . . . . . . . . . . . . . . . . . . 516 23.9 Definition of Result Variables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 517 23.9.1 Definition of Variable Sets . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 517 23.9.2 Selection of Result Variables within a Variable Set . . . . . . . . . . . . . . . . . 518 24 Flickermeter

521

24.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 521 24.2 Flickermeter (IEC 61000-4-15) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 521 24.2.1 Calculation of Short-Term Flicker . . . . . . . . . . . . . . . . . . . . . . . . . . . 521 24.2.2 Calculation of Long-Term Flicker . . . . . . . . . . . . . . . . . . . . . . . . . . . 522 24.3 Flickermeter Calculation

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 522

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CONTENTS 24.3.1 Flickermeter Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 522 24.3.2 Data Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 523 24.3.3 Signal Settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 523 24.3.4 Advanced Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 524 24.3.5 Input File Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 525 25 Quasi-Dynamic Simulation

531

25.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 531 25.2 Technical background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 532 25.3 How to complete a Quasi-Dynamic Simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 533 25.3.1 Defining the variables for monitoring in the Quasi dynamic simulation . . . . . . . 533 25.3.2 Running the Quasi dynamic simulation . . . . . . . . . . . . . . . . . . . . . . . . 534 25.3.3 Considering maintenance outages . . . . . . . . . . . . . . . . . . . . . . . . . . 535 25.4 Analysing the Quasi-dynamic simulation results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 535 25.4.1 Plotting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 535 25.4.2 Quasi-Dynamic simulation reports . . . . . . . . . . . . . . . . . . . . . . . . . . 536 25.4.3 Statistical summary of monitored variables . . . . . . . . . . . . . . . . . . . . . . 536 26 Stability and EMT Simulations

539

26.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 539 26.2 Calculation Methods

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 541

26.2.1 Balanced RMS Simulation

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 541

26.2.2 Three-Phase RMS Simulation

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 541

26.2.3 Three-Phase EMT Simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 542 26.3 Setting Up a Simulation 26.3.1 Basic Options 26.3.2 Step Sizes

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 542 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 543

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 544

26.3.3 Step Size Adaptation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 545 26.3.4 Advanced Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 545 26.3.5 Noise Generation

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 548

26.3.6 Advanced Simulation Options - Load Flow . . . . . . . . . . . . . . . . . . . . . . 548 26.4 Result Objects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 549

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CONTENTS 26.4.1 Saving Results from Previous Simulations . . . . . . . . . . . . . . . . . . . . . . 551 26.5 Simulation Scan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 552 26.5.1 Frequency Scan Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 552 26.5.2 Loss of Synchronism Scan Module . . . . . . . . . . . . . . . . . . . . . . . . . . 552 26.5.3 Variables Scan Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 552 26.5.4 Voltage Scan Module . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 553 26.5.5 Simulation scan example 26.6 Events (IntEvt)

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 553

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 554

26.7 Running a Simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 556 26.8 Models for Stability Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 557 26.9 System Modelling Approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 558 26.9.1 The Composite Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 563 26.9.2 The Composite Frame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 566 26.9.3 The Common Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 570 26.10The Composite Block Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 575 26.10.1 Drawing Composite Block Diagrams and Composite . . . . . . . . . . . . . . . . 577 26.11User Defined (DSL) Models

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 582

26.11.1 Modelling and Simulation Tools . . . . . . . . . . . . . . . . . . . . . . . . . . . . 584 26.11.2 DSL Implementation: an Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 585 26.11.3 Defining DSL Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 589 26.12The DIgSILENT Simulation Language (DSL) . . . . . . . . . . . . . . . . . . . . . . . . . 592 26.12.1 Terms and Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 593 26.12.2 General DSL Syntax . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 593 26.12.3 DSL Variables

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 594

26.12.4 DSL Structure

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 594

26.12.5 Definition Code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 594 26.12.6 Initial Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 595 26.12.7 Equation Code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 598 26.12.8 Equation Statement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 598 26.12.9 DSL Macros

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 599

26.12.10Events and Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 600 26.12.11Example of a Complete DSL Model

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. . . . . . . . . . . . . . . . . . . . . . . . . 601

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CONTENTS 26.13DSL Reference

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 602

26.13.1 DSL Standard Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 602 26.13.2 DSL Special Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 603 26.14MATLAB Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 607 26.14.1 Example Implementation of Voltage Controller

. . . . . . . . . . . . . . . . . . . 608

26.14.2 Additional notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 615 27 Modal Analysis / Eigenvalue Calculation

617

27.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 617 27.2 Theory of Modal Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 617 27.3 How to Complete a Modal Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 620 27.3.1 Completing a Modal Analysis with the Default Options . . . . . . . . . . . . . . . 620 27.3.2 Explanation of Modal Analysis Command Basic Options (ComMod) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 621 27.3.3 QZ method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 621 27.3.4 Selective Modal Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 622 27.3.5 Advanced Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 623 27.3.6 Output Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 625 27.4 Viewing Modal Analysis Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 625 27.4.1 Viewing Modal Analysis Reports in the Output Window . . . . . . . . . . . . . . . 626 27.4.2 Viewing Modal Analysis Results using the built-in Plots . . . . . . . . . . . . . . . 629 27.4.3 Viewing Modal Analysis Results using the Modal Data Browser . . . . . . . . . . 635 27.4.4 Viewing Results in the Data Manager Window . . . . . . . . . . . . . . . . . . . . 637 27.5 Troubleshooting Modal Analysis Calculation Problems . . . . . . . . . . . . . . . . . . . . 639 27.5.1 The Arnoldi/Lanczos Method is slow . . . . . . . . . . . . . . . . . . . . . . . . . 639 28 Model Parameter Identification

641

28.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 641 28.2 Target Functions and Composite Frames . . . . . . . . . . . . . . . . . . . . . . . . . . . 642 28.2.1 The Measurement File Slot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 643 28.2.2 Power System Element Slot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 643 28.2.3 Comparison Slot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 643 28.3 Creating The Composite Identification Model . . . . . . . . . . . . . . . . . . . . . . . . . 644 28.3.1 The Comparison Object . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 645 xx

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CONTENTS 28.4 Performing a Parameter Identification . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 646 28.5 Identifying Primary Appliances . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 648 29 Contingency Analysis

651

29.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 651 29.2 Technical Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 651 29.2.1 Single Time Phase Contingency Analysis . . . . . . . . . . . . . . . . . . . . . . 654 29.2.2 Multiple Time Phases Contingency Analysis . . . . . . . . . . . . . . . . . . . . . 654 29.2.3 Time Sweep Option (Single Time Phase) . . . . . . . . . . . . . . . . . . . . . . 655 29.2.4 Consideration of Predefined Switching Rules . . . . . . . . . . . . . . . . . . . . 655 29.2.5 Parallel Computing Option (Single Time Phase) . . . . . . . . . . . . . . . . . . . 655 29.3 Executing Contingency Analyses . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 655 29.4 The Single Time Phase Contingency Analysis Command . . . . . . . . . . . . . . . . . . 657 29.4.1 Basic Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 658 29.4.2 Effectiveness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 660 29.4.3 Multiple Time Phases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 660 29.4.4 Time Sweep . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 662 29.4.5 Advanced Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 663 29.4.6 Parallel Computing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 664 29.4.7 Calculating an Individual Contingency . . . . . . . . . . . . . . . . . . . . . . . . 666 29.4.8 Representing Contingency Situations Contingency Cases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 666 29.5 The Multiple Time Phases Contingency Analysis Command . . . . . . . . . . . . . . . . 668 29.5.1 Basic Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 669 29.5.2 Effectiveness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 669 29.5.3 Multiple Time Phases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 669 29.5.4 Time Sweep . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 671 29.5.5 Advanced Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 671 29.5.6 Parallel Computing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 671 29.5.7 Defining Time Phases for Contingency Analyses . . . . . . . . . . . . . . . . . . 671 29.5.8 Representing Contingency Situations with Post - Fault Actions . . . . . . . . . . . 673 29.6 Creating Contingency Cases Using Fault Cases and Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 674

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CONTENTS 29.6.1 Browsing Fault Cases and Fault Groups . . . . . . . . . . . . . . . . . . . . . . . 675 29.6.2 Defining a Fault Case . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 675 29.6.3 Defining a Fault Group . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 676 29.7 Creating Contingency Cases Using the Contingency Definition Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 677 29.8 Comparing Contingency Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 679 29.9 Result Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 681 29.9.1 Predefined Report Formats (Tabular and ASCII Reports) . . . . . . . . . . . . . . 681 30 Reliability Assessment

685

30.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 685 30.2 Probabilistic Reliability Assessment Technical Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 687 30.2.1 Reliability Assessment Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . 688 30.2.2 Stochastic Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 689 30.2.3 Calculated Results for Reliability Assessment . . . . . . . . . . . . . . . . . . . . 690 30.2.4 System State Enumeration in Reliability Assessment . . . . . . . . . . . . . . . . 695 30.3 Setting up the Network Model for Reliability Assessment . . . . . . . . . . . . . . . . . . 696 30.3.1 How to Define Stochastic Failure and Repair models . . . . . . . . . . . . . . . . 697 30.3.2 How to Create Feeders for Reliability Calculation . . . . . . . . . . . . . . . . . . 701 30.3.3 Configuring Switches for the Reliability Calculation . . . . . . . . . . . . . . . . . 701 30.3.4 Load Modelling for Reliability Assessment . . . . . . . . . . . . . . . . . . . . . . 702 30.3.5 Modelling Load Interruption Costs

. . . . . . . . . . . . . . . . . . . . . . . . . . 703

30.3.6 System Demand and Load States (ComLoadstate) . . . . . . . . . . . . . . . . . 704 30.3.7 Fault Clearance Based on Protection Device Location . . . . . . . . . . . . . . . 704 30.3.8 How to Consider Planned Maintenance . . . . . . . . . . . . . . . . . . . . . . . 704 30.3.9 Specifying Individual Component Constraints . . . . . . . . . . . . . . . . . . . . 705 30.4 Running The Reliability Assessment Calculation . . . . . . . . . . . . . . . . . . . . . . . 705 30.4.1 How to run the Reliability Assessment . . . . . . . . . . . . . . . . . . . . . . . . 705 30.4.2 Viewing the Load Point Indices . . . . . . . . . . . . . . . . . . . . . . . . . . . . 711 30.4.3 Viewing the System Reliability Indices (Spreadsheet format) . . . . . . . . . . . . 712 30.4.4 Printing ASCII Reliability Reports . . . . . . . . . . . . . . . . . . . . . . . . . . . 713 30.4.5 Using the Colouring modes to aid Reliability Analysis . . . . . . . . . . . . . . . . 713

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CONTENTS 30.4.6 Using the Contribution to Reliability Indices Script . . . . . . . . . . . . . . . . . . 714 31 Optimal Power Restoration

717

31.1 Failure Effect Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 717 31.2 Animated Tracing of Individual Cases . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 722 31.3 Optimal RCS Placement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 722 31.3.1 Basic Options Page

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 723

31.3.2 Output Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 724 31.3.3 Advanced Options Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 724 31.3.4 Example Optimal RCS Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . 724 31.4 Optimal Manual Restoration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 725 31.4.1 OMR Calculation Prerequisites . . . . . . . . . . . . . . . . . . . . . . . . . . . . 726 31.4.2 Basic Options Page

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 726

31.4.3 Advanced Options Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 727 31.4.4 Definition of the objective function . . . . . . . . . . . . . . . . . . . . . . . . . . . 729 31.4.5 Example of an Optimal Manual Restoration Calculation . . . . . . . . . . . . . . . 730 32 Generation Adequacy Analysis

733

32.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 733 32.2 Technical Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 733 32.3 Database Objects and Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 736 32.3.1 Stochastic Model for Generation Object (StoGen) . . . . . . . . . . . . . . . . . . 736 32.3.2 Power Curve Type (TypPowercurve) . . . . . . . . . . . . . . . . . . . . . . . . . 737 32.3.3 Meteorological Station (ElmMeteostat) . . . . . . . . . . . . . . . . . . . . . . . . 737 32.4 Assignment of Stochastic Model for Generation Object . . . . . . . . . . . . . . . . . . . 738 32.4.1 Definition of a Stochastic Multi-State Model . . . . . . . . . . . . . . . . . . . . . 738 32.4.2 Stochastic Wind Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 740 32.4.3 Time Series Characteristic for Wind Generation . . . . . . . . . . . . . . . . . . . 740 32.4.4 Demand definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 742 32.4.5 Generation Adequacy Analysis Toolbar . . . . . . . . . . . . . . . . . . . . . . . . 743 32.4.6 Generation Adequacy Initialisation Command (ComGenrelinc) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 743 32.4.7 Run Generation Adequacy Command (ComGenrel) . . . . . . . . . . . . . . . . . 746 32.5 Generation Adequacy Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 747 DIgSILENT PowerFactory 15, User Manual

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CONTENTS 32.5.1 Draws (Iterations) Plots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 747 32.5.2 Distribution (Cumulative Probability) Plots . . . . . . . . . . . . . . . . . . . . . . 748 32.5.3 Convergence Plots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 751 32.5.4 Summary of variables calculated during the Generation Adequacy Analysis . . . 753 33 Optimal Power Flow

755

33.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 755 33.2 AC Optimization (Interior Point Method) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 755 33.2.1 Basic Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 755 33.2.2 Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 769 33.2.3 Advanced Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 770 33.2.4 Iteration Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 770 33.2.5 Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 772 33.3 DC Optimization (Linear Programming) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 773 33.3.1 Basic Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 774 33.3.2 Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 778 33.3.3 Advanced Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 779 33.3.4 Iteration Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 780 33.4 Contingency Constrained DC Optimization (LP Method) . . . . . . . . . . . . . . . . . . . 781 33.4.1 Basic Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 782 33.4.2 Initialization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 788 33.4.3 Advanced Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 788 33.4.4 Iteration Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 788 33.4.5 Output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 788 34 Techno-Economical Calculation

791

34.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 791 34.2 Requirements for Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 792 34.3 Calculation Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 792 34.3.1 Basic Options Page

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 792

34.3.2 Costs Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 793 34.3.3 Output Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 794 34.4 Example Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 794

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CONTENTS 35 Distribution Network Tools

799

35.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 799 35.2 Voltage Sag . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 799 35.2.1 Calculation Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 800 35.2.2 How to Perform a Voltage Sag Table Assessment . . . . . . . . . . . . . . . . . . 801 35.2.3 Voltage Sag Table Assessment Results . . . . . . . . . . . . . . . . . . . . . . . 802 35.3 Voltage Profile Optimization

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 804

35.3.1 Optimization Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 805 35.3.2 Basic Options Page

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 807

35.3.3 Output Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 808 35.3.4 Advanced Options Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 808 35.3.5 Results of Voltage Profile Optimization . . . . . . . . . . . . . . . . . . . . . . . . 808 35.4 Tie Open Point Optimization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 809 35.4.1 Tie Open Point Optimization Background . . . . . . . . . . . . . . . . . . . . . . . 809 35.4.2 How to run a Tie Open Point Optimization . . . . . . . . . . . . . . . . . . . . . . 810 35.5 Backbone Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 813 35.5.1 Basic Options Page

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 814

35.5.2 Scoring Settings Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 815 35.5.3 Tracing Backbones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 816 35.5.4 Example Backbone Calculation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 816 35.6 Optimal Capacitor Placement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 817 35.6.1 OCP Objective Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 818 35.6.2 OCP Optimization Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 820 35.6.3 Basic Options Page

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 820

35.6.4 Available Capacitors Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 822 35.6.5 Load Characteristics Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 823 35.6.6 Advanced Options Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 824 35.6.7 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 825 36 Cable Sizing

827

36.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 827 36.2 Calculation Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 829 36.2.1 Basic Options Page

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 829

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CONTENTS 36.2.2 Constraints Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 831 36.2.3 Output Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 832 36.2.4 Advanced Options Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 834 36.2.5 Type Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 837 36.3 Cable Sizing Line Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 838 36.3.1 Cable Sizing Line Type Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . 838 36.3.2 Cable Sizing Line Element Parameters . . . . . . . . . . . . . . . . . . . . . . . . 839 36.4 System Technology Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 839 36.5 Predefined Laying Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 840 36.5.1 NF C 15-100 (Tableau 52C) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 840 36.5.2 NF C 13-200 (Tableau 52E) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 844 37 Motor Starting

849

37.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 849 37.2 How to define a motor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 849 37.2.1 How to define a motor Type and starting methodology . . . . . . . . . . . . . . . 849 37.2.2 How to define a motor driven machine . . . . . . . . . . . . . . . . . . . . . . . . 851 37.3 How to run a Motor Starting simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 852 37.3.1 Basic Options Page

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 852

37.3.2 Output Page . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 854 37.3.3 Motor Starting simulation results . . . . . . . . . . . . . . . . . . . . . . . . . . . 855 37.3.4 Motor Starting Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 856 38 Arc-Flash Hazard Analysis

859

38.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 859 38.2 Arc-Flash Hazard Analysis Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . 859 38.2.1 General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 859 38.2.2 Data Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 860 38.3 Arc-Flash Hazard Analysis Calculation Options . . . . . . . . . . . . . . . . . . . . . . . . 861 38.3.1 Arc-Flash Hazard Analysis Basic Options Page . . . . . . . . . . . . . . . . . . . 861 38.3.2 Arc-Flash Hazard Analysis Advanced Options Page . . . . . . . . . . . . . . . . 862 38.4 Arc-Flash Hazard Analysis Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 863 38.4.1 Viewing Results in the Single Line Graphic . . . . . . . . . . . . . . . . . . . . . . 863

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CONTENTS 38.4.2 Arc-Flash Reports Dialogue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 863 38.4.3 Arc-Flash Labels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 863 38.5 Example Arc-Flash Hazard Analysis Calculation . . . . . . . . . . . . . . . . . . . . . . . 864 39 Protection

867

39.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 867 39.1.1 The modelling structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 867 39.1.2 The relay frame . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 868 39.1.3 The relay type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 869 39.1.4 The relay element

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 870

39.2 How to define a protection scheme in PowerFactory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 871 39.2.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 871 39.2.2 Adding protective devices to the network model . . . . . . . . . . . . . . . . . . . 871 39.2.3 Protection single line diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . 875 39.2.4 Locating protection devices within the network model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 876 39.3 Setup of an overcurrent protection scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 877 39.3.1 Overcurrent relay model setup - basic data page . . . . . . . . . . . . . . . . . . 877 39.3.2 Overcurrent relay model setup - max/min fault currents tab . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 879 39.3.3 Configuring the current transformer . . . . . . . . . . . . . . . . . . . . . . . . . . 880 39.3.4 Configuring the voltage transformer . . . . . . . . . . . . . . . . . . . . . . . . . . 883 39.3.5 How to add a fuse to the network model . . . . . . . . . . . . . . . . . . . . . . . 887 39.3.6 Basic relay blocks for overcurrent relays . . . . . . . . . . . . . . . . . . . . . . . 889 39.4 The time-overcurrent plot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 896 39.4.1 How to create a time-overcurrent plot . . . . . . . . . . . . . . . . . . . . . . . . . 897 39.4.2 Understanding the time-overcurrent plot . . . . . . . . . . . . . . . . . . . . . . . 898 39.4.3 Showing the calculation results on the time-overcurrent plot . . . . . . . . . . . . 898 39.4.4 Displaying the grading margins . . . . . . . . . . . . . . . . . . . . . . . . . . . . 899 39.4.5 Adding a user defined permanent current line to the time-overcurrent plot . . . . 900 39.4.6 Configuring the auto generated protection diagram . . . . . . . . . . . . . . . . . 900 39.4.7 Overcurrent plot options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 900

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CONTENTS 39.4.8 Altering protection device characteristic settings from the time-overcurrent plot . 902 39.4.9 How to split the relay/fuse characteristic . . . . . . . . . . . . . . . . . . . . . . . 902 39.4.10 Equipment damage curves . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 905 39.5 Setup and analysis of a distance protection scheme . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 917 39.5.1 Distance relay model setup - basic data page . . . . . . . . . . . . . . . . . . . . 918 39.5.2 Primary or secondary Ohm selection for distance relay parameters . . . . . . . . 918 39.5.3 Basic relay blocks used for distance protection . . . . . . . . . . . . . . . . . . . 918 39.6 The impedance plot (R-X diagram) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 928 39.6.1 How to create an R-X diagram

. . . . . . . . . . . . . . . . . . . . . . . . . . . . 928

39.6.2 Understanding the R-X diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . 929 39.6.3 Configuring the R-X plot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 930 39.6.4 Modifying the relay settings and branch elements from the R-X plot . . . . . . . . 934 39.7 The time-distance plot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 934 39.8 Distance protection coordination assistant . . . . . . . . . . . . . . . . . . . . . . . . . . 939 39.8.1 Distance protection coordination assistant - technical background . . . . . . . . . 939 39.8.2 Worked example of the distance protection coordination assistant . . . . . . . . . 942 39.8.3 Prerequisites for using the distance protection coordination tool . . . . . . . . . . 945 39.8.4 How to run the distance protection coordination calculation . . . . . . . . . . . . 945 39.8.5 Distance protection coordination options . . . . . . . . . . . . . . . . . . . . . . . 945 39.8.6 How to output results from the protection coordination assistant . . . . . . . . . . 947 39.9 Accessing results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 949 39.9.1 Tabular protection setting report . . . . . . . . . . . . . . . . . . . . . . . . . . . . 950 39.9.2 Results in single line graphic

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 953

39.10Short circuit trace . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 954 39.10.1 Short Circuit Trace Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 956 39.11Building a basic overcurrent relay model . . . . . . . . . . . . . . . . . . . . . . . . . . . 957 39.12Appendix - other commonly used relay blocks . . . . . . . . . . . . . . . . . . . . . . . . 966 39.12.1 The frequency measurement block . . . . . . . . . . . . . . . . . . . . . . . . . . 966 39.12.2 The frequency block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 967 39.12.3 The under-/overvoltage block . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 967 40 Network Reduction

xxviii

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CONTENTS 40.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 969 40.2 Technical Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 969 40.2.1 Network Reduction for Load Flow . . . . . . . . . . . . . . . . . . . . . . . . . . . 969 40.2.2 Network Reduction for Short-Circuit

. . . . . . . . . . . . . . . . . . . . . . . . . 970

40.3 How to Complete a Network Reduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . 970 40.3.1 How to Backup the Project (optional) . . . . . . . . . . . . . . . . . . . . . . . . . 970 40.3.2 How to run the Network Reduction tool . . . . . . . . . . . . . . . . . . . . . . . . 971 40.3.3 Expected Output of the Network Reduction . . . . . . . . . . . . . . . . . . . . . 971 40.4 Network Reduction Command . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 973 40.4.1 Basic Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 973 40.4.2 Outputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 975 40.4.3 Advanced Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 975 40.5 Network Reduction Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 976 40.6 Tips for using the Network Reduction Tool

. . . . . . . . . . . . . . . . . . . . . . . . . . 979

40.6.1 Station Controller Busbar is Reduced . . . . . . . . . . . . . . . . . . . . . . . . . 979 40.6.2 Network Reduction doesn’t Reduce Isolated Areas . . . . . . . . . . . . . . . . . 980 40.6.3 The Reference Machine is not Reduced . . . . . . . . . . . . . . . . . . . . . . . 980 41 State Estimation

981

41.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 981 41.2 Objective Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 982 41.3 Components of the PowerFactory State Estimator . . . . . . . . . . . . . . . . . . . . . . 982 41.3.1 Plausibility Check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 983 41.3.2 Observability Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 984 41.3.3 State Estimation (Non-Linear Optimization) . . . . . . . . . . . . . . . . . . . . . 985 41.4 State Estimator Data Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 985 41.4.1 Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 986 41.4.2 Activating the State Estimator Display Option . . . . . . . . . . . . . . . . . . . . 990 41.4.3 Editing the Element Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 991 41.5 Running SE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 993 41.5.1 Basic Setup Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 994 41.5.2 Advanced Setup Options for the Plausibility Check . . . . . . . . . . . . . . . . . 997 41.5.3 Advanced Setup Options for the Observability Check . . . . . . . . . . . . . . . . 997 DIgSILENT PowerFactory 15, User Manual

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CONTENTS 41.5.4 Advanced Setup Options for Bad Data Detection . . . . . . . . . . . . . . . . . . 997 41.5.5 Advanced Setup Options for Iteration Control . . . . . . . . . . . . . . . . . . . . 998 41.6 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 999 41.6.1 Output Window Report . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 999 41.6.2 External Measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1000 41.6.3 Estimated States . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1002 41.6.4 Colour Representation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1003

V

Appendix

1005

A Glossary

1007

B Hotkeys Reference

1013

B.1

Calculation Hotkeys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1013

B.2

Graphic Windows Hotkeys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1013

B.3

Data Manager Hotkeys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1015

B.4

Dialogue Hotkeys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1017

B.5

Output Window Hotkeys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1017

B.6

Editor Hotkeys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1019

C Technical References of Models C.1

1023

Branch Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1024 C.1.1

2-Winding Transformer (ElmTr2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1024

C.1.2

3-Winding Transformer (ElmTr3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1024

C.1.3

Autoransformers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1025

C.1.4

Booster Transformer (ElmTrb) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1025

C.1.5

Overhead Lines Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1025

C.1.6

Cables Systems

C.1.7

Series Capacitances (ElmScap) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1028

C.1.8

Series Reactance (ElmSfilt) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1028

C.1.9

Series Filter (ElmSind) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1028

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1027

C.1.10 Common Impedance (ElmZpu) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1028 C.2

Generators and Loads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1028 C.2.1

xxx

Asynchronous Machine (ElmAsm) . . . . . . . . . . . . . . . . . . . . . . . . . . 1028 DIgSILENT PowerFactory 15, User Manual

CONTENTS

C.3

C.4

C.5

C.6

C.7

C.2.2

Doubly Fed Induction Machine (ElmAsmsc) . . . . . . . . . . . . . . . . . . . . . 1028

C.2.3

Static Generator (ElmGenstat) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1029

C.2.4

PV System (ElmPvsys) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1029

C.2.5

Synchronous Machine (ElmSym) . . . . . . . . . . . . . . . . . . . . . . . . . . . 1029

C.2.6

Loads (ElmLod) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1030

C.2.7

Low Voltage Load (ElmLodlv) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1030

C.2.8

Partial Loads (ElmLodlvp) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1030

C.2.9

Motor Driven Machine (ElmMdm__X) . . . . . . . . . . . . . . . . . . . . . . . . . 1030

Power Electronic Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1030 C.3.1

PWM AC/DC Converter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1030

C.3.2

Rectifier/Inverter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1031

C.3.3

Soft Starter (ElmVar) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1031

C.3.4

DC/DC Converter (ElmDcdc) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1031

Reactive Power Compensation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1031 C.4.1

Neutral Earthing Element (ElmNec) . . . . . . . . . . . . . . . . . . . . . . . . . . 1031

C.4.2

Shunt/Filter Element (ElmShnt) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1031

C.4.3

Static Var System (ElmSvs) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1032

Controllers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1032 C.5.1

Station Controller (ElmStactrl) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1032

C.5.2

Power Frequency Control (ElmSecctrl) . . . . . . . . . . . . . . . . . . . . . . . . 1032

Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1032 C.6.1

AC Voltage Source (ElmVac) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1032

C.6.2

DC Voltage Source (ElmVdc) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1032

C.6.3

AC Current Source (ElmIac) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1032

C.6.4

DC Current Source (ElmDci) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1033

C.6.5

Impulse Source (ElmImpulse) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1033

C.6.6

DC Battery (ElmBattery) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1033

C.6.7

DC Machine (ElmDcm) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1033

C.6.8

External Network (ElmXnet) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1033

C.6.9

Fourier Source (ElmFsrc) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1033

Measurement Devices C.7.1

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1034

Current Measurement (StaImea) . . . . . . . . . . . . . . . . . . . . . . . . . . . 1034

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C.8

C.9

C.7.2

Power Measurement (StaPqmea) . . . . . . . . . . . . . . . . . . . . . . . . . . . 1034

C.7.3

Voltage Measurement (StaVmea) . . . . . . . . . . . . . . . . . . . . . . . . . . . 1034

C.7.4

Phase Measurement Device (Phase Locked Loop, ElmPhi__pll) . . . . . . . . . . 1034

C.7.5

Measurement File (ElmFile) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1034

Digital Devices . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1034 C.8.1

Digital Clock (ElmClock) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1034

C.8.2

Digital Register (ElmReg) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1034

C.8.3

Sample and Hold Model (ElmSamp) . . . . . . . . . . . . . . . . . . . . . . . . . 1035

C.8.4

Trigger Model (ElmTrigger) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1035

Analysis Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1035 C.9.1

Fast Fourier Transform (ElmFft))

. . . . . . . . . . . . . . . . . . . . . . . . . . . 1035

C.10 Miscellaneous . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1035 C.10.1 Surge Arrester (StaSua) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1035 D DPL Reference

1037

D.1

Class Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1037

D.2

DPL Methods and Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1047

D.3

General Functions and Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1058

D.4

xxxii

D.3.1

Object . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1058

D.3.2

General Set . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1084

D.3.3

String . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1095

D.3.4

Time and Date . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1103

D.3.5

Output Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1107

D.3.6

File . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1113

D.3.7

Miscellaneous . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1116

Project Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1126 D.4.1

Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1126

D.4.2

Project Methods (IntPrj) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1134

D.4.3

Project Version Methods (IntVersion) . . . . . . . . . . . . . . . . . . . . . . . . . 1137

D.4.4

Project Folder Methods (IntPrjfolder) . . . . . . . . . . . . . . . . . . . . . . . . . 1139

D.4.5

StudyCaseMethods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1140

D.4.6

Variant Methods (IntVariant) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1143

D.4.7

Variation Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1144 DIgSILENT PowerFactory 15, User Manual

CONTENTS D.4.8 D.5

D.6

D.7

Scenario Methods (IntScenario) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1146

Reporting and Graphical Representation . . . . . . . . . . . . . . . . . . . . . . . . . . . 1148 D.5.1

Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1148

D.5.2

Virtual Instrument Methods: SetVipage . . . . . . . . . . . . . . . . . . . . . . . . 1149

D.5.3

Virtual Instrument Methods: VisPlot/VisPlot2 Methods . . . . . . . . . . . . . . . 1159

D.5.4

Virtual Instrument Methods:VisFft Methods . . . . . . . . . . . . . . . . . . . . . 1178

D.5.5

Virtual Instrument Methods: IntPlot Methods . . . . . . . . . . . . . . . . . . . . . 1179

D.5.6

Graphic Board Methods (SetDesktop) . . . . . . . . . . . . . . . . . . . . . . . . 1183

D.5.7

Text Box Methods (SetLevelvis) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1190

D.5.8

Table Report Methods (ComTablereport) . . . . . . . . . . . . . . . . . . . . . . . 1193

Data Container . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1208 D.6.1

SetFilt Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1208

D.6.2

SetSelect Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1209

D.6.3

Feeder (SetFeeder) Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1216

D.6.4

Path (SetPath) Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1217

D.6.5

IntDplmap Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1220

D.6.6

IntDplvector Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1227

PowerFactory Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1231 D.7.1

General Functions and Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . 1231

D.7.2

Load Flow Calculation (ComLdf) Methods . . . . . . . . . . . . . . . . . . . . . . 1234

D.7.3

Short-Circuit Calculation (ComShc) . . . . . . . . . . . . . . . . . . . . . . . . . . 1235

D.7.4

Time-Domain Simulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1236

D.7.5

Result Export (ComRes) Methods

D.7.6

Contingency Case (ComOutage) Methods . . . . . . . . . . . . . . . . . . . . . . 1238

D.7.7

Contingency Analysis (ComSimoutage) Methods . . . . . . . . . . . . . . . . . . 1240

D.7.8

Contingency Definition (ComNmink) Methods . . . . . . . . . . . . . . . . . . . . 1242

D.7.9

Reliability Assessment (ComRel3) Methods . . . . . . . . . . . . . . . . . . . . . 1244

. . . . . . . . . . . . . . . . . . . . . . . . . . 1237

D.7.10 DPL Command (ComDpl) Methods . . . . . . . . . . . . . . . . . . . . . . . . . . 1247 D.7.11 ComImport Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1247 D.7.12 ComMerge Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1248 D.7.13 ComLink Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1254 D.7.14 ComUcteexp Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1255

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CONTENTS D.8

Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1256 D.8.1

Grid (ElmNet) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1256

D.8.2

Asynchronous Machine (ElmAsm) . . . . . . . . . . . . . . . . . . . . . . . . . . 1257

D.8.3

Double Fed Induction Machine (ElmAsmsc) . . . . . . . . . . . . . . . . . . . . . 1258

D.8.4

Feeder (ElmFeeder) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1259

D.8.5

Boundary (ElmBoundary) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1263

D.8.6

Cubicles (StaCubic) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1264

D.8.7

Composite Model (ElmComp) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1267

D.8.8

Breaker/Switch (ElmCoup) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1267

D.8.9

Line (ElmLne) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1270

D.8.10 Result Object (ElmRes) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1276 D.8.11 Station Control (ElmStactrl) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1288 D.8.12 Substation (ElmSubstat) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1290 D.8.13 Synchronous Machine (ElmSym) . . . . . . . . . . . . . . . . . . . . . . . . . . . 1296 D.8.14 Terminal (ElmTerm) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1299 D.8.15 Tower (ElmTow) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1302 D.8.16 Transformer (ElmTr2 / ElmTr3) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1304 D.8.17

Zone (ElmZone) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1305

D.8.18 Switch (StaSwitch) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1307 D.8.19 Bay (ElmBay) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1309 D.9

Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1310 D.9.1

Induction Machine Type (TypAsm)

. . . . . . . . . . . . . . . . . . . . . . . . . . 1310

D.9.2

Induction Machine Type (TypAsmo) . . . . . . . . . . . . . . . . . . . . . . . . . . 1310

D.9.3

Line Type (TypLne) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1310

D.10 Additional Objects (Int*) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1312 D.10.1 IntEvt Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1312 D.10.2 IntForm Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1312 D.10.3 IntMat Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1314 D.10.4 IntMon Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1320 D.10.5 IntThrating Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1322 D.10.6 IntUser Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1323 D.10.7 IntUserman Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1324

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CONTENTS D.10.8 IntVec Methods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1327 D.11 DDE Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1329 D.12 DPL Extension for MS Office . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1330 D.12.1 Functions for MS Excel . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1330 D.12.2 MS Excel Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1343 D.12.3 Functions for MS Access . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1346 D.12.4 MS Access Examples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1349 E The DIgSILENT Output Language

1355

E.1

Format string, Variable names and text Lines . . . . . . . . . . . . . . . . . . . . . . . . . 1356

E.2

Placeholders . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1356

E.3

Variables, Units and Names . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1357

E.4

Colour . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1359

E.5

Advanced Syntax Elements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1359

E.6

Line Types and Page Breaks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1360

E.7

Predefined Text Macros . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1360

E.8

Object Iterations, Loops, Filters and Includes . . . . . . . . . . . . . . . . . . . . . . . . . 1361

F Element Symbol Definition

1363

F.1

Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1363

F.2

General Symbol Definition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1363

F.3

Geometrical Description

F.4

Including Graphic Files as Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1366

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1364

G Standard Functions DPL and DSL

1367

Bibliography

1369

Index

1371

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DIgSILENT PowerFactory 15, User Manual

Part I

General Information

Chapter 1

About this Guide 1.1

Introduction

This User Manual is intended to be a reference for users of the DIgSILENT PowerFactory software. This chapter provides general information about the contents and the used conventions of this documentation.

1.2

Contents of the User Manual

The first section of the User Manual provides General Information, including an overview of PowerFactory software, a description of the basic program settings, and a description of the PowerFactory data model. The next sections describe PowerFactory administration, handling, and power system analysis functions. In the Power System Analysis Functions section, each chapter deals with a different calculation, presenting the most relevant theoretical aspects, the PowerFactory approach, and the corresponding interface. Additional tools such as the DIgSILENT Programming Language (DPL), the reporting functions, and communication interfaces with other programs are presented in the appendices. The online version of this manual includes additional sections dedicated to the mathematical description of models and their parameters, referred to as Technical References. To facilitate their portability, visualization, and printing, the papers are attached to the online help as PDF documents. They are opened by clicking on the indicated links within the manual. References for DIgSILENT Programming Language functions are also included as appendices of the online manual. It is recommended that new users commence by reading Chapter 4 (PowerFactory Overview), and completing the PowerFactory Tutorials.

1.3

Used Conventions

Conventions to describe user actions are as follows: Buttons and Keys Dialogue buttons and keyboard keys are referred to with bold and underline text formatting. For example, press the OK button in the PowerFactory dialogue, or press CTRL+B on the keyboard. Menus and Icons Menus and icons are usually referenced using Italics. For example, press the User Settings icon , or select Tools → User Settings. . . Other Items "Speech marks" are used to indicate data to be entered by the user, and also to refer to an item defined by the author. For example, consider a parameter "x".

DIgSILENT PowerFactory 15, User Manual

3

CHAPTER 1. ABOUT THIS GUIDE

4

DIgSILENT PowerFactory 15, User Manual

Chapter 2

Contact For further information about the company DIgSILENT , our products and services please visit our web site, or contact us at: DIgSILENT GmbH Heinrich-Hertz-StraSSe 9 72810 Gomaringen / Germany www.digsilent.de

2.1

Direct Technical Support

DIgSILENT experts offer direct assistance to PowerFactory users with valid maintenance agreements via telephone or online via support queries raised on the customer portal. To register for the on-line portal, select Help → Register. . . or go to directly to the registration page (link below). Log-in details will be provided by email shortly thereafter. To log-in to the portal, enter the email (or Login) and Password provided. When raising a new support query, please include the PowerFactory version and build number in your submission, which can be found by selecting Help → About PowerFactory. . . from the main menu. Note that including relevant *.dz or *.pfd file(s) may assist with our investigation into your query. The customer portal is shown in Figure 2.1.1. Phone: +49-(0)7072-9168-50 (German) +49-(0)7072-9168-51 (English) Portal log-in and Registration: http://www.digsilent.de/index.php/support.html

DIgSILENT PowerFactory 15, User Manual

5

CHAPTER 2. CONTACT

Figure 2.1.1: DIgSILENT customer portal

2.2

General Information

For general information about DIgSILENT or your PowerFactory license, please contact us via: Phone: +49-(0)7072-9168-0 Fax: +49-(0)7072-9168-88 E-mail: [email protected]

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DIgSILENT PowerFactory 15, User Manual

Chapter 3

Documentation and Help System DIgSILENT PowerFactory is provided with a complete help package to support users at all levels of expertise. Documents with the basic information of the program and its functionality are combined with references to advanced simulation features, mathematical descriptions of the models and of course application examples. PowerFactory offers the following help resources: • Installation Manual: PowerFactory installation guide, describes the procedures followed to install and set the program. It is available in the PowerFactory installation CD and from the DIgSILENT Customer Portal under ’Download’. Also in this manual is described how to configure PowerFactory for local caching of projects when an external server connection is unavailable (Offline Mode). It is available from the DIgSILENT Customer Portal. The Offline mode guide is available in section 5.4: Offline Mode User Guide. • Tutorial: Basic Information for new users and hands-on tutorial. Access via Help menu (CHM file) of PowerFactory , and the DIgSILENT customer portal (PDF file) by searching for ’Tutorial’ on the ’Knowledge’ section. • User Manual: This document. Access via Help menu of PowerFactory. Current and previous manuals (PDF files) can also be found on the DIgSILENT Customer Portal by search for ’Manual’ on the ’Knowledge’ section. • Technical References: Description of the models implemented in PowerFactory for the different power systems components. The technical reference documents are attached to the online help (Appendix C: Technical References of Models). • Context Sensitive Help: Pressing the key F1 while working with PowerFactory will lead you directly to the related topic inside the User Manual. • PowerFactory Examples: The window PowerFactory Examples provides a list of application examples of PowerFactory calculation functions. Every example comes with an explaining document which can be opened by pressing the corresponding document button. Additional videos are available for demonstrating the software handling and its functionalities. The PowerFactory Examples window will “pop up" automatically every time the software is open, this could be deactivated by unchecking the Show at Startup checkbox. PowerFactory Examples are also accessible on the main menu, by selecting File → Examples. . . . • Release Notes: For all new versions and updates of the program Release Notes are provided, which document the implemented changes. They are available from the DIgSILENT Customer Portal under ’Download’, and on the DIgSILENT webpage. • FAQs: Users with a valid maintenance agreement can access the FAQ section, on the DIgSILENT customer portal under ’Knowledge’. In this section you will find interesting questions and answers DIgSILENT PowerFactory 15, User Manual

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CHAPTER 3. DOCUMENTATION AND HELP SYSTEM regarding specific applications of PowerFactory. See Chapter 2: Contact, for Customer Portal log-in and registration details. • Technical Support: See Chapter 2: Contact • Portal log-in and Registration: http://www.digsilent.de/index.php/support.html • Website: www.digsilent.de

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Chapter 4

PowerFactory Overview The calculation program PowerFactory , as written by DIgSILENT , is a computer aided engineering tool for the analysis of transmission, distribution, and industrial electrical power systems. It has been designed as an advanced integrated and interactive software package dedicated to electrical power system and control analysis in order to achieve the main objectives of planning and operation optimization. “DIgSILENT " is an acronym for “DIgital SImuLation of Electrical NeTworks". DIgSILENT Version 7 was the world’s first power system analysis software with an integrated graphical single-line interface. That interactive single-line diagram included drawing functions, editing capabilities and all relevant static and dynamic calculation features. PowerFactory was designed and developed by qualified engineers and programmers with many years of experience in both electrical power system analysis and programming fields. The accuracy and validity of results obtained with PowerFactory has been confirmed in a large number of implementations, by organizations involved in planning and operation of power systems throughout the world. To address users power system analysis requirements, PowerFactory was designed as an integrated engineering tool to provide a comprehensive suite of power system analysis functions within a single executable program. Key features include: 1. PowerFactory core functions: definition, modification and organization of cases; core numerical routines; output and documentation functions. 2. Integrated interactive single line graphic and data case handling. 3. Power system element and base case database. 4. Integrated calculation functions (e.g. line and machine parameter calculation based on geometrical or nameplate information). 5. Power system network configuration with interactive or on-line SCADA access. 6. Generic interface for computer-based mapping systems. Use of a single database, with the required data for all equipment within a power system (e.g. line data, generator data, protection data, harmonic data, controller data), means that PowerFactory can easily execute all power simulation functions within a single program environment - functions such as load-flow, short-circuit calculation, harmonic analysis, protection coordination, stability calculation, and modal analysis. Although PowerFactory includes some sophisticated power system analysis functions, the intuitive user interface makes it possible for new users to very quickly perform common activities such as load-flow and short-circuit calculations. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 4. POWERFACTORY OVERVIEW The functionality purchased by a user is configured in a matrix, where the licensed calculation functions, together with the maximum number of busses, are listed as coordinates. The user may, as required, configure the interface as well as some functions according to their requirements. Depending on user requirements, a specific PowerFactory license may or may not include all the functions described in this manual. As requirements dictate, additional functionality can be added to a license. These functions can be used within the same program interface with the same network data. Only additional data, as may be required by an added calculation function, need be added.

4.1

General Concept

The general PowerFactory program design concept is summarized as follows: Functional Integration DIgSILENT PowerFactory software is implemented as a single executable program, and is fully compatible with Windows XP/Vista and Windows 7. The programming method employed allows for fast selection of different calculation functions. There is no need to reload modules and update or transfer data and results between different program applications. As an example, the Load Flow, Short-Circuit, and Harmonic Load Flow analysis tools can be executed sequentially without resetting the program, enabling additional software modules and engines, or reading and converting external data files. Vertical Integration DIgSILENT PowerFactory software has adopted a unique vertically integrated model concept that allows models to be shared for all analysis functions. Furthermore, studies relating to “Generation", “Transmission", “Distribution", and “Industrial" analysis can all be completed within PowerFactory . Separate software engines are not required to analyze separate aspects of the power system, or to complete different types of analysis, as DIgSILENT PowerFactory can accommodate everything within one integrated program and one integrated database. Database Integration Single Database Concepts:DIgSILENT PowerFactory provides optimal organization of data and definitions required to perform various calculations, memorization of settings or software operation options. The PowerFactory database environment fully integrates all data required for defining Study Cases, Operation Scenarios, Single Line Graphics, textual and graphical Results, calculation options, and user-defined models, etc. Everything required to model and simulate the power system is integrated into a single database which can be configured for single and/or multiple users. Project Management: All data that defines a power system model is stored in “Project" folders within the database. Inside a “Project" folder, “Study Cases" are used to define different studies of the system considering the complete network, parts of the network, or Variations on its current state. This “project and study case" approach is used to define and manage power system studies in a unique application of the object-oriented software principle. DIgSILENT PowerFactory has taken an innovative approach and introduced a structure that is easy to use, avoids data redundancy, and simplifies the task of data management and validation for users and organizations. Additionally, the application of Study Cases and project Variations in PowerFactory facilitates efficient and reliable reproduction of study results. Multi-User Operation: Multiple users each holding their own projects or working with data shared from other users are supported by a “Multi-user" database operation. In this case the definition of access rights, user accounting and groups for data sharing are managed by a database Administrator. Offline Mode: In some instances, a network connection to a server database may not be avail10

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4.2. DATABASE, OBJECTS, AND CLASSES able. To address this, PowerFactory provides functionality to work in Offline Mode. The required project data is cached to the user’s local machine, which can then later be synchronized to the server database. Offline Mode functionality includes the ability to lock and unlock projects, edit projects as read-only, and limit the database size on the computer(s) working in offline mode. Customization By default, “Beginner" and “Default" user profiles are available in PowerFactory . Profiles can be selected from the main menu under Tools → Profiles. The “Beginner" profile limits the icons displayed on the main toolbar to those typically used by new users, such as load-flow and shortcircuit commands. The database Administrator can create and customize user profiles, in particular: • Customize the element dialogue pages that are displayed. • Customize element dialogue parameters. Parameters can be Hidden (not shown) or Disabled (shown but not editable). • Fully configure Main Toolbar and Drawing Toolbar menus, including definition of custom DPL Commands and Templates with user-defined icons. • Customize Main Menu, Data Manager, and context-sensitive menu commands. Chapter 6: User Accounts, User Groups, and Profiles (Section 6.5 Creating Profiles) details the customization procedure. Note: When right-clicking with the mouse button, the available menu options depend on the location of the mouse pointer. For example, if a load is selected, the menu options are those appropriate for loads, whereas when the mouse pointer is over the Output Window, the menu options are those appropriate for the Output Window. These menus are collectively referred to as ’Context sensitive menu’s’.

4.2

Database, Objects, and Classes

PowerFactory uses a hierarchical, object-oriented database. All the data, which represents power system Elements, Single Line Graphics, Study Cases, system Operation Scenarios, calculation commands, program Settings etc., are stored as objects inside a hierarchical set of folders. The folders are arranged in order to facilitate the definition of the studies and optimize the use of the tools provided by the program. The objects are grouped according to the kind of element that they represent. These groups are known as “Classes" within the PowerFactory environment. For example, an object that represents a synchronous generator in a power system belongs to a Class called ElmSym, and an object storing the settings for a load flow calculation belongs to a Class called ComLdf. Object Classes are analogous to computer file extensions. Each object belongs to a Class and each Class has a specific set of parameters that defines the objects it represents. As explained in Section 4.8 (User Interface), the edit dialogues are the interfaces between the user and an object; the parameters defining the object are accessed through this dialogue. This means that there is an edit dialogue for each class of objects. Note: Everything in PowerFactory is an object, all the objects belong to a Class and are stored according to a hierarchical arrangement in the database tree.

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4.3

PowerFactory Simulation Functions

PowerFactory incorporates a comprehensive list of simulation functions, described in detail in Volume II of the manual, including the following: • Load Flow Analysis, allowing meshed and mixed 1-,2-, and 3-phase AC and/or DC networks (Chapter 21: Load Flow Analysis). • Low Voltage Network Analysis (Section 21.2.3: Advanced Load Options). • Short-Circuit Analysis, for meshed and mixed 1-,2-, and 3-phase AC networks (Chapter 22: ShortCircuit Analysis). • Harmonic Analysis (Chapter 23: Harmonics Analysis). • RMS Simulation (time-domain simulation for stability analysis, Chapter 26: Stability and EMT Simulations). • EMT Simulation (time-domain simulation of electromagnetic transients, Chapter 26: Stability and EMT Simulations). • Eigenvalue Analysis (Chapter 27: Modal Analysis / Eigenvalue Calculation). • Model Parameter Identification (Chapter 28: Model Parameter Identification). • Contingency Analysis (Chapter 29: Contingency Analysis). • Reliability Analysis (Chapter 30: Reliability Assessment). • Generation Adequacy Analysis (Chapter 32: Generation Adequacy Analysis). • Optimal Power Flow (Chapter 33: Optimal Power Flow). • Distribution Network Optimization (Chapter 35: Distribution Network Tools). • Protection Analysis (Chapter 39: Protection). • Network Reduction (Chapter 40: Network Reduction). • State Estimation (Chapter 41: State Estimation).

4.4

General Design of PowerFactory

PowerFactory is primarily intended to be used and operated in a graphical environment. That is, data is entered by drawing the network Elements, and then editing and assigning data to these objects. Data is accessed from the graphics page by double-clicking on an object. An input dialogue is displayed and the user may then edit the data for that object. Figure 4.4.1 shows the PowerFactory Graphical User Interface (GUI) when a project is active. The GUI is discussed in further detail in Section 4.8

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4.4. GENERAL DESIGN OF POWERFACTORY

Figure 4.4.1: PowerFactory Main Window

All data entered for objects is hierarchically structured in folders for ease of navigation. To view the data and its organization, a “Data Manager" is used. Figure 4.4.2 shows the Data Manager window. The Data Manager is similar in appearance and functionality to a Windows Explorer window. Within the Data Manager, information is grouped based on two main criterion: 1. Data that pertains directly to the system under study, that is, electrical data. 2. Study management data, for example, which graphics should be displayed, what options have been chosen for a Load Flow, which Areas of the network should be considered for calculation, etc.

Figure 4.4.2: PowerFactory Data Manager DIgSILENT PowerFactory 15, User Manual

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CHAPTER 4. POWERFACTORY OVERVIEW Note that most user-actions can be performed in both the Single Line Graphic and the Data Manager. For example, a new terminal can be added directly to the Single Line Graphic, or alternatively created in the Data Manager. In the latter case, the terminal could be shown in the Single Line Graphic by “drawing existing net elements", by “dragging and dropping" from the Data Manager, or by creating a new Graphical Net Object in the Data Manger (advanced).

4.5

Type and Element Data

Since power systems are constructed using standardized materials and components, it is convenient to divide electrical data into two sets, namely “Type" data and “Element" data sets. • Characteristic electrical parameters, such as the reactance per km of a line, or the rated voltage of a transformer are referred to as Type data. Type objects are generally stored in the Global Library or Project Library, and are shown in red. For instance, a Line Type object, TypLne ( ). • Data relating to a particular instance of equipment, such as the length of a line, the derating factor of a cable, the name of a load, the connecting node of a generator, or the tap position of a transformer are referred to as Element data. Element objects are generally stored in the Network Data folder, and are shown in green. For instance, a Line Element object, ElmLne ( ). Consider the following example: • A cable has a Type reactance of “X" Ohms/ km, say 0.1 Ohms/ km. • A cable section of length “L" is used for a particular installation, say 600 m, or 0.6 km. • This section (Element) therefore has an reactance of X * L Ohms, or 0.06 Ohms. Note that Element parameters can be modified using Operation Scenarios (which store sets of network operational data), and Parameter Characteristics (which can be used to modify parameters based on the Study Case Time, or other user-defined trigger).

4.6

Data Arrangement

The PowerFactory database supports multiple users (as mentioned in 4.1) and each user can manage multiple projects. “User Account" folders with access privileges only for their owners (and other users with shared rights) must then be used. User accounts are of course in a higher level than projects. Figure 4.6.1 shows a snapshot from a database as seen by the user in a Data Manager window, where there is a User Account for “User", and one project titled “Project". The main folders used to arrange data in PowerFactory are summarized below:

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4.6. DATA ARRANGEMENT

Figure 4.6.1: Structure of a PowerFactory project in the Data Manager

4.6.1

Global Library

This global Library contains a wide range of pre-defined models, including: • Type data for standard components such as conductors, motors, generators, and transformers. • Standard control system frames, models, and macros (i.e. transfer functions and logic blocks, etc). • Standard CT, VT, fuse, and relay models. • Pre-defined model templates, including: – Battery System with frequency control (10 kV, 30 MVA). – Double Fed Induction Wind Turbine Generator (0.69 kV, 2 MW). – Fully Rated Converter Wind Turbine Generator (0.4 kV, 2 MW). – Variable Rotor Resistance Wind Turbine Generator (0.69 kV, 0.66 MW). – Photovoltaic System (0.4 kV, 0.5 MVA) DIgSILENT PowerFactory 15, User Manual

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CHAPTER 4. POWERFACTORY OVERVIEW • Standard DPL scripts, including scripts to: – Produce PV and QV curves. – Minimize the Net Present Value of project (Variation) costs by varying the project service date. – Conduct time-sweep load flow calculations.

4.6.2

Project Library

The project Library contains the equipment Types, network operational information, DPL scripts, templates, and user-defined models (generally) only used within a particular project. A particular project may have references to the project Library and / or global Library. The Project Library folder and subfolders are discussed in detail in Chapter 12 (Project Library).

4.6.3

Diagrams

Single Line Graphics are defined in PowerFactory by means of graphic folders of class IntGrfNet ( ). Each diagram corresponds to a IntGrfNet folder. They are stored in the Network Diagrams folder ( ) of the Network Model. Single line diagrams are composed of graphical objects, which represent components of the networks under study. Graphical components reference network components and symbol objects (IntSym). The relation between graphical objects and network components allows the definition and modification of the studied networks directly from the Single Line Graphics. Network components can be represented by more than one graphical object (many IntGrf objects can refer to the same network component). Therefore, one component can appear in several diagrams. These diagrams are managed by the active Study Case, and specifically by an object called the Graphics Board. If a reference to a network diagram is stored in a Study Case’s Graphics Board, when the Study Case is activated, the diagram is automatically opened. Diagrams can be easily added and deleted from the Graphics Boards. Each diagram is related to a specific Grid (ElmNet). When a Grid is added to an active Study Case, the user is asked to select (among the diagrams pointing to that grid) the diagrams to display. References to the selected diagrams are then automatically created in the corresponding Graphics Board. Chapter 9 (Network Graphics (Single Line Diagrams)), explains how to define and work with single line graphics.

4.6.4

Network Data

The Network Data folder holds network data (Element data) in “Grid" folders, network modification information in “Variation" folders, and object Grouping information. Grids In PowerFactory , electrical network information is stored in “Grid" folders (ElmNet, ). A power system may have as many grids as defined by the user. These grids may or may not be interconnected. As long as they are active, they are considered by the calculations. Data may be sorted according to logical, organizational and/or geographical areas (discussed further in Section 4.7: Project Structure). An example of this approach is the Tutorial project provided with the Getting Started Manual. In this project, a distribution network and a transmission network are created and analyzed separately. At a later stage both networks are connected and the analysis of the complete system is carried out.

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4.6. DATA ARRANGEMENT

Note: A Grid (and in general any object comprising the data model) is active when it is referred to by the current study case. Only objects referred in the current (active) Study Case are considered for calculation. In the Data Manager, the icon of an active Grid is shown in red, to distinguish it from inactive Grids.

For details of how to define grids refer to Chapter 8.Basic Project Definition, Section 8.2 (Creating New Grids). Variations During the planning and assessment of a power system, it is often necessary to analyze different variations and expansion alternatives of the base network. In PowerFactory these variations are modelled by means of “Variations". These are objects that store and implement required changes to a network, and can be easily activated and deactivated. The use of Variations allows the user to conduct studies under different network configurations in an organized and simple way. ) are stored inside the Variations folder ( ) which resides in the NetVariation objects (IntScheme, work Model folder. Variations are composed of “Expansion Stages" (IntStage), which store the changes made to the original network(s). The application of these changes depends on the current study time and the activation time of the Expansion Stages. The study time is a parameter of the active Study Case, and is used to situate the current study within a time frame. The activation time is a parameter given to the Expansion Stages, to determine whether or not, according to the study time, the changes contained within the Expansion Stages are applied to the network. If the activation time precedes the study time, the changes are applied to the original network. The changes of a subsequent expansion stage add to the changes of its predecessors. In order that changes to the network configuration are applied and can be viewed, a Variation must be activated. These changes are contained in the expansion stage(s) of this active Variation. Once the Variation is deactivated, the network returns to its original state. Changes contained in an Expansion Stage can be classified as: • Modifications to network components. • Components added to the network. • Components deleted from the network. Note: If there is no active Operation Scenario, modifications to operational data will be stored in the active Variation.

Grouping Objects In addition to Grid folders, the Network Data folder contains a set of objects that allow further grouping of network components. By default, when a new project is created, new empty folders to store these grouping objects is created inside the Network Model folder. For details of how to define grouping objects, refer to Chapter 13: Grouping Objects.

4.6.5

Operation Scenarios

Operation Scenarios may be used to store operational settings, a subset of Element data. Operational data includes data that relates to the operational point of a device but not to the device itself e.g. the tap position of a transformer or the active power dispatch of a generator. Operation Scenarios are stored in the Operation Scenarios folder. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 4. POWERFACTORY OVERVIEW

4.6.6

Study Cases

The Study Cases folder holds study management information. Study Cases are used to store information such as command settings, active Variations and Operations Scenarios, graphics to be displayed, and study results. See Chapter 11 (Study Cases) for details.

4.6.7

Settings

Project settings such as user-defined diagram styles for example, which differ from global settings, are stored inside the Settings folder.

4.7

Project Structure

The structure of project data depends on the complexity of the network, use of the model, and user preferences. The user has the flexibility to define network components directly within the Grid, or to organize and group components in a way that simplifies management of project data. Consider the example network data arrangement shown in Figure 4.7.1 In this case, two busbar systems (ElmSubstat in PowerFactory ) have been defined, one at 132 kV, and one at 66 kV. The two busbar systems are grouped within a Site, which includes the 132 kV / 66 kV transformers (not shown in Figure 4.7.1). A Branch composed of two line sections and a node connects “132 kV Busbar" to “HV terminal". Grouping of components in this way simplifies the arrangement of data within the Data Manager, facilitates the drawing overview diagrams, and facilitates storing of Substation switching configurations.

Figure 4.7.1: Example Project Structure

The following subsections provide further information regarding the PowerFactory representation of key network topological components.

4.7.1

Nodes

In PowerFactory , nodes connecting lines, generators, loads, etc. to the network are generally called “Terminals" (ElmTerm). Depending on their usage within the power system, Terminals can be used to represent Busbars, Junctions, or Internal Nodes (their usage is defined by a drop down menu found in the Basic Data page of the terminal dialogue). According to the selected usage, different calculation functions are enabled; for example the short-circuit calculation can be performed only for busbars, or for busbars and internal nodes, and so on.

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4.7. PROJECT STRUCTURE

4.7.2

Branches

Elements with multiple connections are referred to “Branches" (as distinct from a “Branch Element", which is a grouping of elements, discussed in Section 4.7.7). Branches include two-connection elements such as transmission lines and transformers, and three-connection elements such as threewinding transformers, AC/DC converters with two DC terminals, etc. For information about how to define transmission lines (and cables) and sections refer to Chapter 9: Network Graphics, Section 9.2(Defining Network Models with the Graphical Editor). Technical information about transmission line and cable models is provided in Appendix C (Line (ElmLne)).

4.7.3

Cubicles

When any branch element is directly connected to a Terminal, PowerFactory uses a “Cubicle" (StaCubic) to define the connection. Cubicles can be visualized as the panels on a switchgear board, or bays in a high voltage yard, to which the branch elements are connected. A Cubicle is generally created automatically when an element is connected to a node (note that Cubicles are not shown on the Single Line Graphic).

4.7.4

Switches

To model complex busbar-substation configurations, switches (ElmCoup) can be used. Their usage can be set to Circuit-Breaker, Disconnector, Switch Disconnector, or Load Switch. The connection of an ElmCoup to a Terminal is carried out by means of an automatically generated Cubicle without any additional switch (StaSwitch) object.

4.7.5

Substations

Detailed busbar configurations are represented in PowerFactory as Substations (ElmSubstat). Separate single line diagrams of individual substations can be created. Substation objects allow the use of running arrangements to store/set station circuit breaker statuses (see Chapter 12: Project Library, Section 12.3: Operational Library). For information about how to define substations refer to Chapter 9: Network Graphics, Section 9.2(Defining Network Models with the Graphical Editor) and Chapter 10, Section 10.3(Defining Network Models with the Data Manager).

4.7.6

Sites

Network components including Substations and Branches can be grouped together within a “Site" (ElmSite). This may include Elements such as substations / busbars at different voltage levels. For information about how to define sites refer to Chapter 10, Section 10.3(Defining Network Models with the Data Manager).

4.7.7

Branch Elements

Similar to Substations, Terminal Elements and Line Elements can be stored within an object called a Branch Element (ElmBranch). Branches are “composite" two-port elements that may be connected to a Terminal at each end. They may contain multiple Terminals, Line sections (possible including various line types), and Loads etc, but be represented as a single Branch on the Single Line Graphic. As for Substations, separate diagrams for the detailed branch can be created with the graphical editor.

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CHAPTER 4. POWERFACTORY OVERVIEW For information about how to define branches refer to Chapter 9: Network Graphics, Section 9.2(Defining Network Models with the Graphical Editor) and Chapter 10, Section 10.3(Defining Network Models with the Data Manager).

4.8

User Interface

An overview of the PowerFactory user interface is provided in this section, including general discussion of the functionality available to enter and manipulate data and graphics. Aspects of the user interface are discussed in further detail in the following chapters, in particular: • Chapter 6 (User Accounts, User Groups, and Profiles). • Chapter 9(Network Graphics (Single Line Diagrams)). • Chapter 10 (Data Manager).

4.8.1

Overview

The main PowerFactory window is shown in Figure 4.8.1

Figure 4.8.1: PowerFactory user interface

Key features of the main window are as follows: 1. The main window includes a description of the PowerFactory version, and standard icons to Minimize, Maximize/Restore, Resize, and Close the window. 20

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4.8. USER INTERFACE 2. The main menu bar includes drop-down menu selections. The main menu is discussed further in section 4.8.2 (Menu Bar). 3. The Main Toolbar includes commands and other icons. The Main Toolbar is discussed in further detail in section 4.8.3 (Main Toolbar). 4. The Graphical Editor displays single line diagrams, block diagrams and/or simulation plots of the active project. Studied networks and simulation models can be directly modified from the graphical editor by placing and connecting elements. 5. When an object is right clicked (in the graphical editor or in the data manager) a context sensitive menu with several possible actions appears. 6. When an object is double clicked its edit dialogue will be displayed. The edit dialogue is the interface between an object and the user. The parameters defining the object are accessed through this edit dialogue. Normally an edit dialogue is composed of several “pages". Each page groups parameters that are relevant to a certain function. In Figure 4.8.1 the Load Flow page of a generator is shown, where only generator parameters relevant to load flow calculations are shown. 7. The “Data Manager" is the direct interface with the database. It is similar in appearance and functionality to a Windows Explorer window. The left pane displays a symbolic tree representation of the complete database. The right pane is a data browser that shows the content of the currently selected folder. The data manager can be accessed by pressing the Data Manager icon ( ) on the left of the main toolbar. It is always ’floating’, and more than one can be active at a time. Depending on how the user navigates to the Database Manager, it may only show the database tree for selecting a database folder, or it may show the full database tree. The primary functionality of the Data Manager is to provide access to power system components/objects. The data manager can be used to edit a group of selected objects within the data manager in tabular format. Alternatively, objects may be individually edited by double clicking on an object (or rightclick → Edit). 8. The output window is shown at the bottom of the PowerFactory window. The output window cannot be closed, but can be minimized. The output window is discussed in further detail in section 4.8.4 (The Output Window). 9. The “Project Overview" window is displayed by default on the left side of the main application window between the main toolbar and the output window. It displays an overview of the project allowing the user to assess the state of the project at a glance and facilitating easy interaction with the project data.

4.8.2

Menu Bar

The menu bar contains the main PowerFactory menus. Each menu entry has a drop down list of menu options and each menu option performs a specific action. To open a drop down list, either click on the menu entry with the left mouse button, or press the Alt key together with the underlined letter in the menu. Menu options that are shown in grey are not available, and only become available as the user activates projects or calculation modes, as required.

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CHAPTER 4. POWERFACTORY OVERVIEW

Figure 4.8.2: The help menu on the Menu bar

For example as show in Figure 4.8.2: • To access PowerFactory tutorials: Press Alt-H to open the help menu. Use the keyboard to select Start Tutorial. Press Execute to open the Tutorial. Note that the on-line Getting Started Tutorial is identical to the printed version. • To access the User Manual: Left click the Help menu. Left-click the option User Manual to open the electronic User Manual.

4.8.3

Main Toolbar

The main PowerFactory toolbar provides the user with quick access to the main commands available in the program (see Figure 4.8.1). Buttons that appear in grey are only active when appropriate. All command icons are equipped with balloon help text which are displayed when the cursor is held still over the icon for a moment, and no key is pressed. To use a command icon, click on it with the left mouse button. Those icons that perform a task will automatically return to a non-depressed state when that task is finished. Some command icons will remain depressed, such as the button to Maximise Output Window. When pressed again, the button will return to the original (non-depressed) state. This section provides a brief explanation of the purpose of the icons found on the upper part of the toolbar. Icons from the lower part of the toolbar are discussed in Chapter 9(Network Graphics (Single Line Diagrams)). Detailed explanations for each of the functions that the icons command are provided in the other sections of the manual. Open Data Manager Opens a new instance of the Database Manager. When the option “Use Multiple Data Manager" is enabled in the user settings menu (User Settings → General) the user will be able to open as many instances of the data manager as required. If “Use Multiple Data Manager" is disabled in the user settings menu, the first instance of the data manager will be re-opened. For more information on the Data Manager refer to Chapter 10. Edit Relevant Objects for Calculation Provides a list of elements (coloured in green) and types (coloured in red) that are in an active Grid: e.g. transformer types, line elements, composite models, etc. When an object icon is selected, all objects from the selected class(es) will be shown in a browser. 22

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4.8. USER INTERFACE Date/Time of Calculation Case (SetTime) Displays the date and time for the case calculation. This option is used when parameter characteristics of specific elements (e.g. active and reactive power of loads) are set to change according to the study time, or a Variation status is set to change with the study time. Edit Trigger Displays a list of all Triggers that are in the active Study Case. These Triggers can be edited in order to change the values for which one or more characteristics are defined. These values will be modified with reference to the new Trigger value. All Triggers for all relevant characteristics are automatically listed. If required, new Triggers will be created in the Study Case. For more information, see Chapter 16: Parameter Characteristics, Load States, and Tariffs. Section 16.2 (Parameter Characteristics). Data Verification (ComCheck) Performs model data verification, see Section 21.5 (Troubleshooting Load Flow Calculation Problems). Calculate Load-Flow (ComLdf) Activates the load-flow command dialogue. For more information about the specific settings, refer to Chapter 21 (Load Flow Analysis). Calculate Short-Circuit (ComShc) Activates the short-circuit calculation command dialogue. For more information, refer to Chapter 22 (Short-Circuit Analysis). Edit Short-Circuits Edits Short-Circuit events. Events are used when a calculation requires more than one action or considers more than one object for the calculation. Multiple fault analysis is an example of this. If, for instance, the user multi-selects two busbars (using the cursor) and then clicks the right mouse button Calculate → Multiple Faults a Short-circuit event list will be created with these two busbars in it. Execute DPL Scripts Displays a list of DPL scripts that are available. See section 4.9 for a general description of DPL scripts, and Chapter 19 (The DIgSILENT Programming Language - DPL) for detailed information. Output Calculation Analysis (ComSh) Presents calculation results in various formats. The output is printed to the Output Window and can be viewed, or copied for use in external reports. Several different reports, depending on the calculation, can be created. For more information about the output of results refer to Chapter 17:Reporting and Visualizing Results, Section 17.2.3 (Output of Results). Documentation of Device Data (ComDocu) Presents a listing of device data (a device is the model of any physical object that has been entered into the project for study). This output may be used in reports, and for checking data that has been entered. Depending on the element chosen for the report, the user has two options; generate a short listing, or a detailed report. For more information please refer to Chapter 17:Reporting and Visualizing Results, Section 17.2.3 (Output of Results). Comparing of Results On/Off Turns on/off comparing of calculation results. Used to compare results where certain settings

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CHAPTER 4. POWERFACTORY OVERVIEW or designs options of a power system have been changed from one calculation to the next. For more information please refer to Chapter 17:Reporting and Visualizing Results, Section 17.3 (Comparisons Between Calculations). Edit Comparing of Results (CommDiff) Enables the user to select the cases/ calculation results that are to be compared to one another, or to set the colouring mode for the difference reporting. For more information please refer to Chapter 17:Reporting and Visualizing Results, Section 17.3 (Comparisons Between Calculations). Update Database Utilizes the current calculations results (i.e. the calculation ’output’ data) to change input parameters (i.e. data the user has entered). An example is the transformer tap positions, where these have been calculated by the load-flow command option “Automatic Tap Adjust of Tap Changers." For more information refer to Chapter 17:Reporting and Visualizing Results, Section 17.3 (Comparisons Between Calculations). Save Operation Scenario Saves the current operational data to an Operation Scenario (e.g. load values, switch statuses, etc.). See Chapter 14 (Operation Scenarios). Break Stops a transient simulation or DPL script that is running. Reset Calculation Resets any calculation performed previously. This icon is only enabled after a calculation has been carried out. Note: In User Settings, on the General page, if ’Retention of results after network change’ is set to ’Show last results’ in the User Settings (see Chapter 7: User Settings, section 7.1), results will appear in grey on the Single Line Diagram and on the Flexible Data tab until the calculation is reset, or a new calculation performed.

User Settings (SetUser) User options for many global features of PowerFactory may be set from the dialogue accessed by this icon. For more information refer to Chapter 7 (User Settings). Maximize Graphic Window Maximizes the graphic window. Pressing this icon again will return the graphic window to its original state. Maximize Output Window Maximizes the output window. Pressing this icon again will return the output window to its original state. Change Toolbox In order to minimize the number of icons displayed on the taskbar, some icons are grouped based on the type of analysis, and are only displayed when the relevant category is selected from the Change Toolbox icon. In Figure 4.8.3, the user has selected RMS/EMT Simulation, and therefore only icons relevant for RMS and EMT studies are displayed to the right of the Change Toolbox icon. If, for example, Reliability Assessment were selected then icons to the right of the Change 24

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4.8. USER INTERFACE Toolbox icon would change to those suitable for a reliability assessment.

Figure 4.8.3: Change Toolbox selection

4.8.4

The Output Window

In addition to results presented in the Single Line Graphics and / or Data Manager, the Output Window displays other textual output, such as error messages, warnings, command messages, device documentation, result of calculations, and generated reports, etc. This section describes Output Window use and functionality. Sizing and Positioning the Output Window The default location of the Output Window is “docked" (fixed) at the bottom of the main window, as shown in Figure 4.8.1 It can be minimized, but not closed. When right-clicking the mouse button with the cursor in the output windows area, the context sensitive menu of the output window appears. The output window can then be undocked by deselecting the Dock Output Window. The undocked output window is still confined to the main window, but now as a free floating window. This can occur unintentionally when the user left clicks the tool bar for the output window and drags the mouse (keeping the mouse button down) to somewhere outside of the output window boundaries. To rectify this simply left-click in the title bar of the undocked window and drag it down to the bottom of the screen where it will dock once more (if you have right-clicked and unticked “Docking View" then right click and select “Docking View" once more). The upper edge of the output window shows a splitter bar which is used to change the size of the output window. The “drag" cursor appears automatically when the cursor is placed on the splitter bar. The left mouse button can be pressed when the “drag" cursor is visible. This will turn the splitter bar to grey and the output window can now be resized by holding down the mouse button and moving the mouse up or down. The output window may be moved and resized by: • Dragging the splitter bar (grey bar at the upper edge of the output window) when the output window is in “docking mode". • Double-clicking the frame of the output window to dock/undock it from the main window. • Pressing the Maximize Graphic Window icon ( board by hiding the output window. DIgSILENT PowerFactory 15, User Manual

) on the main toolbar to enlarge the graphics

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CHAPTER 4. POWERFACTORY OVERVIEW • Pressing the Maximize Output Window icon ( window.

) icons on the main toolbar to enlarge the output

Output Window Options The contents of the output window may be stored, edited, redirected, etc., using the icons shown on the right-hand pane of the output window. Some commands are also available from the context sensitive menu by right-clicking the mouse in the output window pane. Opens an editor. The user can copy and paste text from the output window to the editor, and manually type data in the editor. Opens a previously saved output file. Saves the selected text to an ASCII file, or the complete contents of the output window if no selection was made. Copies the selected text to the Windows Clipboard. Text may then be pasted in other programs. Clears the output window by deleting all messages. Note that when the user scrolls through previous messages in the output window, the output window will no longer automatically scroll with new output messages. The Clear All icon will “reset" scrolling of the output window. Searches the text in the output window for the occurrences of a given text. Changes the font used in the output window. Redirects the output window to a file. The output window will not display messages while this icon is depressed. Redirects the output window to be printed directly. Redirects the output window to be printed directly. Using the Output Window The Output Window facilitates preparation of data for calculations, and identification of network data errors. Objects listed in the output window (with a folder name and object name) can be double-clicked with the left mouse button to open an edit dialogue for the object. Alternatively, the object can be right-clicked and then Edit, Edit and Browse Object, or Mark in Graphic selected. For example, if a Synchronous Machine Element does not have a Type defined, the load-flow will not solve and a message will be reported. (see Figure 4.8.4). This simplifies the task of locating objects in the Single Line Graphic.

Figure 4.8.4: Output Window Context Sensitive Menu Output Window Context Sensitive Menu As mentioned in the previous section, to show the Output Windows context sensitive menu, right-click the mouse button whilst pointing at the object name. The available option are as follows: 26

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4.8. USER INTERFACE • Edit Object: Opens the edit dialogue of the selected object. • Edit and Browse Object: Opens a Data Manager and displays the Element and its parameters. • Mark in Graphic: Marks the selected element in the Single Line Graphic and zooms into the region it is placed. Output Window Legend The Output Window uses colours and other formatting to distinguish between different types of messages, and for bar graph results. Used text message formats are as follows: DIgSI/err - ... Error messages. Format: red coloured. DIgSI/info - .... Information messages. Format: green coloured. DIgSI/wrng - ... Warning message. Format: brown coloured. DIgSI/pcl - ...’ Protocol message. Format: blue coloured. Text only Output text. Format: black coloured. Output Window Graphical Results Reports of calculation results may contain bar graphical information. The “voltage profiles" report after a load-flow command, for instance, produces bar graphs of the per-unit voltages of busbars. These bars will be coloured blue, green or red if the “Verification" option in the load-flow command dialogue has been enabled. They will be hatch-crossed if the bars are too large to display. Part of a bar graph output is shown in Figure 4.8.5 The following formatting is visible:

Figure 4.8.5: Output window bar diagram

• Green Solid Bar: Used when the value is in the tolerated range. • Blue Solid Bar: Used when the value is below a limit. • Red Solid Bar: Used when the value is above a limit. • Hatch-crossed Bar: Used when the value is outside the range.

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CHAPTER 4. POWERFACTORY OVERVIEW Copying from the Output Window The contents of the Output Window, or parts of its contents, may be copied to the built-in editor of PowerFactory , or to other programs. Normally, not all selected lines will be copied and the format of the copied text may undergo changes. The latter is caused by the fact that the PowerFactory output window uses special formatting “escape sequences", which other programs may not support. The lines that are to be copied is determined by the Output Window settings. When text from the output window is copied, an info message will be displayed, informing the user about the current settings (see Figure 4.8.6). From this dialogue, the Output Window User Settings may be modified, and the Info message may be disabled.

Figure 4.8.6: The output window Info Message

4.9

DIgSILENT Programming Language (DPL) Scripts

The DIgSILENT Programming Language DPL offers an interface to the user for the automation of tasks in PowerFactory . By means of a simple programming language and in-built editor, the user can define automation commands (scripts) to perform iterative or repetitive calculations on target networks, and post-process the results. To find the name of an object parameter to be used in a DPL script, simply hover the mouse pointer over the relevant field in an object dialogue. For example, for a General Load, on the Load Flow page, hover the mouse pointer over the Active Power field to show the parameter name “plini". User-defined DPL scripts can be used in all areas of power system analysis, for example: • Network optimization. • Cable-sizing. • Protection coordination. • Stability analysis. • Parametric sweep analysis. • Contingency analysis. DPL scripts may include the following: 28

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4.9. DIGSILENT PROGRAMMING LANGUAGE (DPL) SCRIPTS • Program flow commands such as ’if-else’ and ’do-while’. • PowerFactory commands (i.e. load-flow or short-circuit commands: ComLdf, ComShc). • Input and output routines. • Mathematical expressions. • PowerFactory object procedure calls. • Subroutine calls. DPL command objects provide an interface for the configuration, preparation, and use of DPL scripts. These objects may take input parameters, variables and/or objects, pass these to functions or subroutines, and then output results. DPL commands are stored inside the Scripts folder ( ) in the project directory. Consider the following simple example shown in Figure 4.9.1 to illustrate the DPL interface, and the versatility of DPL scripts to take a user-selection from the Single Line Graphic. The example DPL script takes a load selection from the Single Line Graphic, and implements a while loop to output the Load name(s) to the Output Window. Note that there is also a check to see if any loads have been selected by the user.

Figure 4.9.1: Example DPL Script

For further information about DPL commands and how to write and execute DPL scripts refer to Chapter 19 (The DIgSILENT Programming Language - DPL), and Appendix D DPL Reference.

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Part II

Administration

Chapter 5

Program Administration This chapter provides information on how to configure the program, and how to log on. More Detailed descriptions of the installation, database settings and additional information on these topics can be found in the PowerFactory Installation Manual.

5.1

Program Installation and Configuration

In general there are 3 main questions to be answered before installing the software, the answers to these questions will determine the installation settings: • License: Where should the license key(s) reside? • Installation: Where should PowerFactory be installed? • Database: Where should the database reside? Once PowerFactory has been set up in a computer PowerFactory can be started directly by clicking either on the shortcut on the Desktop or by selecting PowerFactory in the in the Windows start menu. PowerFactory will start automatically and create a User account when logging on for the first time. As a default user name for PowerFactory the User name from Windows will be used if the user is working in a single-user-database environment. In case more users accounts have been created a Log-On dialogue will pop up and the User can select the User name used for the session. The user will be asked to enter a password if the user has defined a password for the user account. In a multi-user-database installation (see Chapter 6: User Accounts, User Groups, and Profiles) new accounts and passwords are created by the administrator. The Administrator account is created when installing PowerFactory and is used to create and manage user’s accounts in a multi-user environment (see Chapter 6: User Accounts, User Groups, and Profiles). To log on as administrator, the shortcut from the Windows Start Menu can be used. As default the administrator account password is Administrator. When already running a PowerFactory session, the user can select Tools → Switch User in the main menu to log-on as Administrator. For further information about the roll of the database administrator please refer Section 6.2: The Database Administrator. Changes to the default settings of the installation settings can be carried out by means of the ’SetConfig’ dialogue. This dialogue can be found in the Windows Start menu. Through the Database and Licence tabs of the SetConfig dialogue, the answers to the questions above are provided and the program installation is configured. Administrator rights are necessary to perform changes to the settings. Once

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CHAPTER 5. PROGRAM ADMINISTRATION PowerFactory is started, the Configurations Dialgue can be accessed via Tools → Configuration in the main menu of PowerFactory . A detailed description of the installation procedure and the program configuration alternatives is given in the PowerFactory Installation Manual.

5.2

The SetConfig Dialogue

The SetConfig-dialogue is used to apply changes to the Configuration settings. Windows Administration rights are required.

5.2.1

General

In this page the user can select the application language for the session.

5.2.2

Database

In this page it is specified how the database is going to be used. You can select among: • A single-user database which resides locally on each computer. • A multi-user database which resides on an remote server. Here all users have access to the same data simultaneously. In this case user accounts are created and administrated exclusively by the Administrator. DIgSILENT PowerFactory provides drivers for the following multi-user database systems: • Oracle. • Microsoft SQL Server. For further information about the database configuration please refer to the PowerFactory Installation Manual.

5.2.3

License

In order to run the program, the user require to define the License Setting in the License page of the SetConfig-dialogue. The options are described below, more information about the licenses types is available in the PowerFactory Installation Manual Demo request When starting PowerFactory for the first time with this option, the DIgSILENT License Activation dialogue is opened with the instructions to get the activate the installation. PowerFactory Workstation This option is for single-user clients with a license key (also known as a dongle or hardlock). PowerFactory Server 34

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5.3. WORKSPACE OPTIONS This option if for multi-user clients with a network license key which allows access to several users over a network. The network license key requires an additional program which is also part of the installation package: License Server. When using PowerFactory Server, the computer name or the IP network address of the license server is required. Advanced RPC-Settings If a network license key with protocol based communication is used, the ’Advanced RPC-Settings’ must be given. These fields, are in the Advanced tab of the License page. The ’RPC’ settings must be the ones specified in the license server. For detailed information the network administrator should be consulted, also more information is available in the PowerFactory Installation Manual.

5.2.4

Workspace

The Workspace tab allows the User to set the Workspace directory and the Workspace backup directory. In the Workspace the local database, the result files and the log-files are saved. For more options how to configure and use the workspace, please refer to chapter 5.3.

5.2.5

External Application

The External Application tap is used to set the Python editor path. This setting is taken by Python functionality.

5.2.6

Advanced Settings

The advanced program settings should only be changed under the guidance of the DIgSILENT PowerFactory support (see Chapter 2 Contact)

5.3

Workspace options

By selecting Tools → Workspace in the main menu the user is able to perform several steps as follows.

5.3.1

Show Workspace Directory

The user is able to see the workspace directory by clicking Tools → Workspace→ Show workspace directory.

5.3.2

Import and Export Workspace

To import the workspace the user can select Tools → Workspace→ Import Workspace.... This is a convenient way to import the entire workspace after a new installation. Accordingly, to export the workspace the user can select Tools → Workspace→ Export Workspace.... The package will be saved as a .zip

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CHAPTER 5. PROGRAM ADMINISTRATION format. The option Tools → Workspace→ Import Workspace from 14.x or 15.0 allows the user to import the workspace from an older version of PowerFactory .

5.3.3

Show Default Export Directory

The selection Tools → Workspace→ Show Default Export Directory in the main menu offers the user to see the directory that is used for the export.

5.4

Offline Mode User Guide

This section describes user actions relevant when working in Offline mode.How to install the Offline Mode is described in the PowerFactory Installation Manual.

5.4.1

Functionality in Offline mode

5.4.1.1

Start Offline Session

Preconditions: • A PowerFactory user account must already exist in the Online database. The PowerFactory "Administrator" user is able to create user accounts. • The user mustn’t be logged on in an Online session. In the example showed in figure 5.4.1 User 2 and User 3 are able to start an Offline session, but not User 1, who is already logged on in an Online session.

Figure 5.4.1: Users allowed to start Offline session Note: the Administrator user isn’t allowed to work in Offline mode, but only in Online mode.

Steps to create an Offline session: • Start PowerFactory . In the Log on dialogue enter the user name and password. • On the "Database" tab insert the Offline Proxy Server settings (see figure 5.4.2)

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5.4. OFFLINE MODE USER GUIDE

Figure 5.4.2: Log-on dialogue. Database page • Press OK • An info message is shown. (fig. 5.4.3)

Figure 5.4.3: Info message • Press OK • After initialization the usual PowerFactory application window will is shown.

5.4.1.2

Release Offline Session

• Open the main menu File → Offline→ Terminate Offline session • A warning message is shown to confirm the synchronization. • Press Yes • Then all unsynchronized local changes are transferred to the server and the local Offline database is removed.

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CHAPTER 5. PROGRAM ADMINISTRATION 5.4.1.3

Synchronize All

Synchronizes the global data (new users, projects added, projects removed, projects moved) and all subscribed projects. • Open the main menu File → Offline→ Synchronize all

5.4.1.4

Subscribe Project for reading only

• Open the Data Manager and navigate to the project • Right-click on the project stub. A context menu is shown. • Select Subscribe project in Offline mode for reading only Then the project is retrieved from the Offline Proxy Server and stored in the local Offline DB cache.

5.4.1.5

Subscribe Project for reading and writing

Write access to the project is required. • Open the Data Manager and navigate to the project • Right-click on the project stub. A context menu is shown. • Select Subscribe project in Offline mode for reading and writing

5.4.1.6

Unsubscribe Project

• Open the Data Manager and navigate to the project • Right-click on the project. A context menu is shown. • Select Unsubscribe project in Offline mode

5.4.1.7

Add a new project

A new project is created in Offline mode. It is available only in this Offline session. Later this project should be published to other users and synchronized to the Online database. • Create new project or import an PFD file with a project • Open the Data Manager and navigate to the project • Right-click on the project stub. A context menu is shown. • Select Subscribe project in Offline mode for reading and writing

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5.4. OFFLINE MODE USER GUIDE 5.4.1.8

Synchronize Project

Synchronizes a subscribed project. If the project is subscribed for reading only, the local project will be updated from the Online database. If the project is subscribed for reading and writing, the changes from the local Offline database will be transferred to the Online database. • Open the Data Manager and navigate to the project • Right-click on the project stub. A context menu is shown. • Select Synchronize

5.4.2

Functionality in Online mode

5.4.2.1

Show current Online/Offline sessions

The session status for each user is shown in the Data Manager.

Figure 5.4.4: Online and Offline Users

In figure 5.4.4: • User 1 and Administrator are logged in an Online session. They are marked by the green ONLINE icon. • User 2 has started an Offline session. It is marked by the red OFFLINE icon. • Public, Demo, and User 3 are not logged on at all.

5.4.3

Terminate Offline session

It might be necessary that an Offline session has to be terminated by the Administrator e.g. if the computer where the Offline session was initialized is now damaged and can’t be used any more, and the user wants to start a new Offline session on a different computer. The Administrator is able terminate such a session: • Right-click on the user object; the context menu is shown. • Select Terminate session (see fig. 5.4.5)

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CHAPTER 5. PROGRAM ADMINISTRATION

Figure 5.4.5: Terminate Offline session • A warning message is shown to confirm the synchronization. • Press Yes As shown in figure 5.4.6 User 2 has no active session now:

Figure 5.4.6: Online Users

5.5 5.5.1

Housekeeping Introduction

Housekeeping automates administration of certain aspects of the database, in particular purging projects, emptying user recycle bins and the deletion of old projects. Housekeeping is triggered by the execution of a Windows Scheduled Task; this can be set up to run at night, thus improving performance during the day by moving regular data processing to off-peak periods. An additional benefit to housekeeping is that users will need to spend less time purging projects and emptying recycle bins, something in particular that can slow down the process of exiting PowerFactory . Housekeeping is only available for multi-user databases (e.g. Oracle, SQL Server). For details about how to schedule housekeeping, see the PowerFactory Installation Manual.

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5.5. HOUSEKEEPING

5.5.2

Configuring permanently logged-on users

Normally housekeeping will not process data belonging to logged-on users; however, some user accounts (e.g. those for a control room) may be connected to PowerFactory permanently. These users can be configured to allow housekeeping to process their data whilst logged-on. This is done from the User Settings dialogue (see figure 5.5.1). Regardless of this setting, housekeeping will not operate on a user’s active project.

Figure 5.5.1: The User Settings Dialogue: housekeeping for connected users

5.5.3

Configuring housekeeping tasks

The SetHousekeeping object is used to control which housekeeping tasks are enabled (see figure 5.5.2). It is recommended that you move this object from Database∖System∖Configuration∖Housekeeping to Database∖Configuration ∖Housekeeping, in order to preserve your configuration through database upgrades. The following sections discuss the different housekeeping tasks shown on the SetHousekeeping object.

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Figure 5.5.2: The SetHousekeeping object

5.5.4

Configuring deletion of old projects

If ‘Delete projects based on last activation’ is set on the SetHousekeeping object, then when housekeeping executes, for each user, each project in turn will be considered for automatic deletion. The project properties determine whether a project can be automatically deleted, as shown in figure 5.5.3. The default setting is for project deletion to be off. When set on, the default retention period is 60 days. These defaults can be changed for new projects by using a template project (under Configuration/Default in the Data Manager tree).

Figure 5.5.3: Project properties

You can change the settings for many existing projects at once using the tabular pane of the Data Manager window (select the relevant column, right-click and choose Modify Values). A value of ’1’ is 42

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5.5. HOUSEKEEPING equivalent to the Housekeeping project deletion radio button being set to ‘On’. (see figure 5.5.4). You can also change projects in bulk via the tabular window resulting from a Find operation, though note that executing a Find is potentially a lengthy operation.

Figure 5.5.4: Setting parameters for many projects at once

A project will be deleted by the housekeeping task if it meets the following criteria: 1. The project is configured for automatic deletion on the Storage page of the project properties. 2. The last activation of the project is older than the retention setting on the project. 3. It is not a base project with existing derived projects 4. It is not a special project (user settings, or anything under System or Configuration trees) 5. The project is not locked (e.g. active). 6. The owner of the project is not connected, unless that user is configured to allow concurrent housekeeping (see section 5.5.2).

5.5.5

Configuring purging of projects

If ‘Purge projects’ is set on the SetHousekeeping object, then when housekeeping executes, each project in turn will be considered for purging. A project that is already locked (e.g. an active project) is not purged. The criteria for housekeeping to purge a project are: • if the project has been activated since its last purge.

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CHAPTER 5. PROGRAM ADMINISTRATION • if it is now more than a day beyond the object retention period since last activation, and the project hasn’t been purged since then. • if the project is considered to have invalid metadata (e.g. is a pre 14.0 legacy project, or a PFD import without undo information). Once housekeeping is configured to purge projects you can consider disabling the automatic purging of projects on activation, thus preventing the Yes/No dialogue popping up. To do this set ’Automatic Purging’ to Off on the Storage page of the Project properties dialogue. You can also set this parameter to Off for many projects at a time (see methods described in section 5.5.4).

5.5.6

Configuring emptying of recycle bins

If ‘Delete recycle bin objects’ is set on the SetHousekeeping object, then when housekeeping executes, each user’s recycle bin in turn will be examined. Entries older than the number of days specified on the SetHousekeeping object (see figure 5.5.2) will be deleted.

5.5.7

Monitoring Housekeeping

Once deployed, how do you know that housekeeping is operating effectively? For example, it could be failing every night with a connection error. An administrator should regularly check that housekeeping is working. The primary check is to inspect the HOUSEKEEPING_LOG table via SQL or the data browsing tools of your multi-user database. For each run, housekeeping will insert a new row to this table showing the start and end date/time and the completion status (success or failure). Other statistics such as the number of deleted projects are kept. Note that absence of a row in this table for a given scheduled day indicates that the task failed before it could connect to the database. In addition to the HOUSEKEEPING_LOG table, there is also a detailed log of a Housekeeping run in the log file of the Housekeeper user.

5.5.8

Summary of Housekeeping Deployment

The basic steps to implement housekeeping are: 1. Set up the Windows Scheduled Task, as described in the PowerFactory Installation Manual.. 2. Configure users expected to be active during housekeeping, as described in section 5.5.2. 3. Configure the SetHousekeeping object as described in section 5.5.3. 4. If using the project deletion task, configure automatic deletion properties for new projects, as described in section 5.5.4. 5. If using the project deletion task, configure automatic deletion properties for existing projects, as described in section 5.5.4. 6. Regularly monitor HOUSEKEEPING_LOG table to check for success after housekeeping runs, as described in 5.5.7.

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Chapter 6

User Accounts, User Groups, and Profiles This chapter provides details of how to create and manage user accounts, user groups, and profiles. Key objectives of the user account managing system are to: • Protect the ’system’ parts of the database from changes by normal (non-Administrator) users. • Protect parts of the databases belonging to user “A" from changes by user “B". • Facilitate sharing of user data. The user account managing system provides each user with their own “private" database space. The user is nevertheless able to use shared data, either from the common system database or from other users, and may enable other users to use data from their private database. The user account managing system manages this whilst using only one single database in the background, which allows for simple backup and management of the overall database. The default name for a PowerFactory user is the Windows user name, which ia automatically created when PowerFactory is started for the first time.

6.1 PowerFactory Database Overview A brief introduction to the top level structure of the PowerFactory database is convenient before presenting the user accounts and their functionality. The data in PowerFactory is stored inside a set of hierarchical directories. The top level structure is constituted by the following folders: The Configuration folder Contains company specific customizing for user groups, user default settings, project templates and class templates for objects. Configuration folder is read only for normal users. The main Library folder Contains all standard types and models provided with PowerFactory. The main library folder is read only for normal users. The System folder Contains all objects that are used internally by PowerFactory. The system folder is read only for all normal users. Changes are only permitted when logged on as the Administrator, and should be conducted under the guidance of DIgSILENT customer support. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 6. USER ACCOUNTS, USER GROUPS, AND PROFILES User account folders Contain user project folders and associated objects and settings. The structure described above is illustrated in Figure 6.1.1

Figure 6.1.1: Basic database structure

6.2

The Database Administrator

A database administrator account is created with the PowerFactory installation. The main functions of the administrator are: • Creation and management of user accounts. • System database maintenance under the guidance of the DIgSILENT customer support. Under a multiuser database environment, the administrator is the only user with permissions to: • Add and delete users. • Define users groups. • Set individual user rights. • Restrict or allow calculation functions. • Set/reset user passwords. • Create and edit Profiles (see Section 6.4 for details). The administrator is also the only user that can modify the main library and the system folders. Although the administrator has access to all the projects of all the users, it does not have the right to perform any calculation. To log on as administrator, there are two options: • Select the Shortcut in the Windows Start Menu PowerFactory 15.1 (Administrator). • Log into PowerFactory as a normal User and select via the Main menu Tools → Switch User. Select Administrator and enter the corresponding password. By default the administrator password is Administrator. For further information about the administrator roll, please refer to the PowerFactory Installation Manual. 46

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6.3. CREATING AND MANAGING USER ACCOUNTS

6.3

Creating and Managing User Accounts

In the case of an installation with a local database, the default name for a PowerFactory user is the Windows user name, which is automatically created when PowerFactory is started for the first time. (see Chapter 5: Program Administration). In this case the program will automatically create and activate the new account, without administrator intervention. In order to create other PowerFactory users if required, the ’User Manager’ object can be used as described below: In multi-user database installations, the administrator creates new user accounts by means of a tool called the ’User Manager’, which is found in the Configuration folder. To create a new user: • Log on as administrator. You can do so by starting the PowerFactory 15.1 (Administrator) shortcut in the Windows Start menu or by switching the user via Tools → Switch User in the main tool bar. • In the left pane of the Data Manager click on Configuration folder to display its contents. • Double click on the User Manager icon (

, rigth pane) and press the Add User. . . button.

The User edit dialogue will be displayed: • In the General tab, enter the new user name and password. • If a licensed version with a restricted number of functions is used (i.e. you may have 4 licences with basic functionality, but only 2 stability licences), the License tab may be used to define the functions that a user can access. The Multi User Database option (bottom of the tab) should be checked for all users that will access the multi user database. The administrator can edit any user account to change the user name, set new calculation rights or change the password. To edit an existing user account: • Right-click on the desired user and select Edit from the context sensitive menu. The User edit dialogue will be displayed. Any user can edit her/his own account by means of the User edit dialogue. In this case only the full name and the password can be changed. Note: The administrator is the only one who may delete a user account. Although users can delete all projects inside their account folder, they cannot delete the account folder itself or the standard folders that belong to it (i.e. the Recycle Bin or the Settings folder).

6.4

Creating User Groups

Any project or folder in a user account may be shared. This action can be performed selectively by sharing only with certain user groups. User groups are created by the administrator via the User Manager. To create a new user group: • Log on as administrator. • In the Data Manager open the Configuration folder and double click on the User Manager icon( DIgSILENT PowerFactory 15, User Manual

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CHAPTER 6. USER ACCOUNTS, USER GROUPS, AND PROFILES • In the User manager dialogue that appears press Add Group. . . • Enter the name of the new group, optionally a description and press Ok. • The new group is automatically created in the User Groups directory of the Configuration folder. The administrator can change the name of an existing group by means of the corresponding edit dialogue (right clicking on it and selecting Edit from the context sensitive menu). Via the context sensitive menu, groups can also be deleted. The administrator can add users to a group by: • Copying the user in the Data Manager (right click on the user and select Copy from the context sensitive menu). • Selecting a user group in the left pane of the Data Manager. • Pasting a shortcut of the copied user inside the group (right-click the user group and select Paste Shortcut from the context sensitive menu). Users are taken out of a group by deleting their shortcut from the corresponding group. The administrator can also set the Groups Available Profiles on the Profile tab of the Group dialogue. For information about sharing projects please refer to Chapter 18 (Data Management).

6.5

Creating Profiles

Profiles can be used to configure toolbars, menus, dialogue pages, and dialogue parameters. By default, PowerFactory includes “Base Package" and “Standard" profiles, selectable from the main menu under Tools → Profiles. Selecting the “Base Package" profile limits icons shown on the Main Toolbar to those that are used with the Base Package of the software. The “Standard" profile includes all available PowerFactory icons. Profiles are created in the Configuration → Profiles folder by selecting the New Object icon and then Others → Settings→ Profile. An Administrator can create and customize profiles, and control User/User Group selection of profiles from the Profile tab of each group. Figure 6.5.1 shows the Profile dialogue for a new profile, CustomProfile, and Figure 6.5.2 illustrates aspects of the GUI that may be customized using this profile. This section describes the customization procedure.

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Figure 6.5.1: Profile Dialogue

Figure 6.5.2: GUI Customization using Profiles

6.5.1

Tool Configuration

Definition of Icons Icons can be defined in the Configuration → Icons folder by selecting the New Object icon and then Others → Other Elements→ Icon. From the Icon dialogue, icon images can be imported and exported. Icons should be 19 pixels by 19 pixels in Bitmap format (recommended to be 24-bit format). Command Configuration Figure 6.5.3 shows the Tool Configuration Commands tab.

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Figure 6.5.3: Commands Configuration. • Command: This is the selected DPL script (which should generally be located in the Configuration → DPL commands folder), or selected Com* object. • Edit: If selected, the DPL command dialogue will appear when a Command is executed. If deselected, the DPL command dialogue will not appear when a Command is executed. • Icon: Previously created icons can be selected, which will be shown on the menu where the command is placed. If no icon is selected, a default icon will appear (a Hammer, DPL symbol, or default Com* icon, depending on the Class type). Template Configuration: Figure 6.5.4 shows the Tool Configuration Templates tab.

Figure 6.5.4: Template Configuration • Template The name of the template. The name may be for a unique template, or include wild´ cards (such as *.ElmLne) for selection of a group of templates. Templates should be in SSys´ tem/Library/Busbar SystemsŠ folder, or in the STemplatesŠ folder of the active project. • Drawing modeThe drawing mode can be set where there are multiple diagrammatic representations for a template (such as for a substation). Three options are available: 50

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6.5. CREATING PROFILES – Blank will place the default (detailed) graphic of the template. – Simplified will place the simplified graphic of the template. – Composite will place a composite representation of the template. • Symbol name Sets the representation of templates with a composite drawing mode (e.g. GeneralCompCirc or GeneralCompRect). • Icon Previously created icons can be selected, which will be shown on the menu where the template is placed. If no icon is selected, a default icon will appear (a Template symbol or custom icon). • Description This description will be displayed when a user hovers the mouse pointer over the icon. If left blank, the template name will be displayed.

6.5.2

Configuration of Toolbars

The Main Toolbar and Drawing Toolbars can be customized using the Toolbar Configuration. The field Toolboxes may either refer to a Toolbox Configuration (SetTboxconfig) or a Toolbox Group Configuration (SetTboxgrconfig), which may in-turn refer to one or more Toolbox Configurations. Figure 6.5.5 shows an example where there is a main toolbox, and a toolbox group. The toolbox group adds a Change Toolbox icon to the menu, which allows selection of Basic Commands and Custom Commands groups of commands.

Figure 6.5.5: Toolbar Configuration

Each toolbox can be customized to display the desired icons, such as illustrated in Figure 6.5.6

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Figure 6.5.6: Toolbox Configuration

Prior to customizing the displayed buttons and menu items etc, the user should first define any required custom Commands and Templates. A Tool Configuration object can be created in the Configuration → Profiles folder, or within a user-defined Profile, by selecting the New Object icon and then Others → Settings→ Tool Configuration. If created in the Profiles folder, the commands will be available from the “Standard" profile. Conversely, if the Tool Configuration object is created within a profile (SetProfile) the commands and templates will only be available for use in this profile. If there is a Tool Configuration within a user-defined profile, as well as in the Profiles folder, the Tool Configuration in the user-defined profile will take precedence. Optionally, customized icons can be associated with the Commands and Templates.

6.5.3

Configuration of Menus

The Main Menu, Data Manager, Graphic, Virtual Instruments, and Output Window menus can be customized from the Menu Configuration dialogue. The Change to Configuration View button of the Profile dialogue is used to display description identifiers for configurable items, such as illustrated in the contextsensitive menu shown in Figure 6.5.7. The Menu Configuration includes a list of entries to be removed from the specified menu. Note that a Profile may include multiple menu configurations (e.g. one for each type of menu to be customized).

Figure 6.5.7: Menu Configuration

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6.5.4

Configuration of Dialogue Pages

The Dialogue Page Configuration may be used to specify the Available and Unavailable Dialogue pages shown when editing elements, such as illustrated in Figure 6.5.8. Note that Users can further customize the displayed dialogue pages from the Functions tab of their User Settings.

Figure 6.5.8: Dialogue Page Configuration

6.5.5

Configuration of Dialogue Parameters

The Dialogue Configuration may be used to customize element dialogue pages, such as illustrated for a Synchronous Machine element in Figure 6.5.9. “Hidden Parameters" are removed from the element dialogue page, whereas “Disabled Parameters" are shown but cannot be modified by the user. A Profile may include multiple dialogue configurations (e.g. one for each class to be customized). Note that if a there is a Dialogue Configuration for say, Elm* (or similarly for ElmLne,ElmLod), as well as a Dialogue Configuration for ElmLne (for example), the configuration settings will be merged.

Figure 6.5.9: Dialogue Configuration Note: Configuration of Dialogue parameters is an advanced feature of PowerFactory , and the user should be cautious not to hide or disable dependent parameters. Please seek assistance from DIgSILENT support if required.

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6.5.6

References

Profiles can also contain references to configurations. This allows several profiles to use the same configurations. These referenced configurations can either be stored in another profile or in a subfolder of the “Profiles" folder (e.g. a user-defined profile can use configurations from a pre-defined profile).

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Chapter 7

User Settings The User Settings dialogue, shown in Figure 7.0.1, offers options for many global features of PowerFactory. This chapter is dedicated to describe this options. The User settings dialogue may be opened either by clicking the User Settings button ( ) on the main tool bar, or by selecting the Options → User Settings. . . menu item from the main menu.

Figure 7.0.1: User Settings dialogue

7.1

General Settings

The general settings include (Figure 7.0.1): Confirm Delete Activity Pops up a confirmation dialogue whenever something is about to be deleted. Open Graphics Automatically Causes the graphics windows to re-appear automatically when a project is activated. When not checked, the graphics window must be opened manually. Beep on user errors May be de-selected to suppress sounds. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 7. USER SETTINGS Use Multiple Data Manager When enabled, more than one data manager dialogue can be opened at a time. When disabled only one data manager may be opened at a time and pressing the New Data Manager button will pop up the minimized data manager. Use operating system Format for Date and Time The operating system date and time settings are used when this is checked. Use Default Graphic Converter. Edit Filter before Execute Presents the filter edit dialogue when a filter is selected, allowing the user to edit the filter before application. However, this is sometimes irksome when a user is applying a filter several times. Thus one may choose to go straight to the list of filtered objects when the filter is applied by un-checking this option. Always confirm Deletion of Grid Data When this option checked a confirmation dialogue is popped up when the user deletes grid data. Decimal Symbol Selects the symbol selected to be used for the decimal point. Use Standard Database Structure In order to simplify the operation of PowerFactory for users who do not use the program often, or who are just starting out certain restrictions may be introduced into the database structure, for example, allowing only ’Type’ data to be placed in Library folders (when this option is un-checked). However, this may be irksome for advanced users or those who are used to the standard database working where a great deal of flexibility is permitted, so as to suit the users needs, and thus the standard structure may be engaged by checking this option. System Stage Profile The ability to create system stages may be limited by this option. Existing system stages will still be visible but the right menu options that create new revisions or system stages will be removed. This is once again a tool that may be used to ’simplify’ PowerFactory for users not familiar with the program by limiting the operations that they may use. Retention of results after network change when the option “Show last results" is selected, modifications to network data or switch status etc. will retained the results, these will be shown on the single line diagram and on flexible data pages in grey until the user reset the results (e.g. by selecting Reset Calculation, or conducting a new calculation).

7.2

Graphic Windows Settings

The graphic windows has the following settings. Cursor settings Defines the cursor shape: • Arrow A normal, arrow shaped cursor. • Tracking cross A small cross. General Options Valid for all graphs: • Show Grid only if stepsize will be least Grid points smaller than the selected size will not be shown. • Show Text only if height will be least Text smaller than the selected size will not be shown. • No. of Columns in Drawing Tools Floater Specifies the width of the graphics toolbar when this is a floating window. 56

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7.3. DATA MANAGER SETTINGS • No. of Columns in Drawing Tools Docker Specifies the width of the graphics toolbar when it is docked on the right side of the drawing space. • Line factor when printing The width of all lines in the graphics will be multiplied by the specified percentage when printing. Update Hidden pages always Results in all graphical pages on a graphics board being updated, even when they are not visible. Note that this can slow the processing speed considerably. The advantage is that no updating is required when a different graphics page is selected. Exclude Feeder Colours May be used to exclude colours, by number code, which are to be used for feeder definitions. This is used to prevent the use of colours which are already used for other purposes. Ranges of colour numbers are entered as ’2-9’. Multiple ranges of colours must separated by commas, as in ’2-9;16-23’. Update Graphic while Simulation is running Use own background colour for single line graphics If the option is enabled, the user can define the background colour of the single line graphics by using the pop up menu and then pressing OK. In the Advanced tab of the Graphic Window page more graphic setting options are available: Allow Resizing of branch objects If the option is enabled, the user can left click a branch element within the single line graphic and then resize it. Edit Mode Cursor Set Allows the selection of the mouse pointer shape. Mark Objects in Region Defines how objects within an user defined region of the single line graphic (defined by left clicking and then drawing a rectangle) are selected: • Complete Only the objects, that are completely enclosed in the defined region, are selected. • Partial All the objects within the defined area are selected. Show balloon Help Enables or disables the balloon help dialogues. For information about the Graphic Window refer to Chapter 9(Network Graphics (Single Line Diagrams)).

7.3

Data Manager Settings

The data manager page specifies which object types will be displayed or hidden in the tree representation, and whether confirmation prompts will appear when objects or data is changed in the data manager itself.

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CHAPTER 7. USER SETTINGS Show in Treelist Object classes that are selected will be displayed in the database tree. Browser • Save data automatically The data manager will not ask for confirmation every time a value is changed in the data browser when this option is selected. • Sort Automatically Specifies that objects are automatically sorted (by name) in the data browser. Operation Scenario If the Save active Operation Scenario automatically is enabled, the period for automatic saving must be defined. Export/Import Data Configures the export and import of PowerFactory ’DZ’-files, as follows: • Binary DataSaves binary data, such as results in the result folders, to the ’DZ’ export files according to selection. • Export References to Deleted Objects Will also export references to objects which reside in the recycle bin. Normally, connections to these objects are deleted on export. • Enable export of activated projects Will permit the export of an activated project. Folders for Global Library The default global type folder is the System/Library/Types folder. This default folder contains many predefined object types, but objects within this folder may not be changed by the user (read-only access). This option allows the user to specify a different ”Global Type Folder”, possibly a company specific and defined type library. For information about the PowerFactory Database Manager refer to Chapter 10 (Data Manager).

7.4

Output Window Settings

The output window settings control the way in which messages selected by the user, in the output window are to be copied for pasting into other programs. Whichever options are checked will determine what will be copied. The text in the output window itself will not be influenced. Escape sequences are special hidden codes which are used for colouring the text, or other formatting commands. Some text processing programs are not capable of using the PowerFactory escape codes. The Text Only option should be set in such cases. The text in the output window itself will not be influenced by the options chosen here. The number of lines displayed in the output window may also be limited.

7.5

Functions Settings

The functions settings page provides check boxes for the function modules that are accessible from the data manager or from the object edit dialogues. The user may choose to see only certain modules in 58

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7.6. DIRECTORIES order to “unclutter" dialogues. This may also be used to protect data by allowing only certain calculation functionality to be seen by certain users. This is particularly useful in a multi-user environment or in when inexperienced users utilize PowerFactory .

7.6

Directories

• Compiled DSL Models Pre-compiled DSL models may be available for use as external models. The DSL directory should be directed to the correct folder/ directory in order for PowerFactory to find these models. • PFM-DSM

7.7

Editor

The editor which is used to enter large pieces of text (such as DPL scripts, objects descriptions, etc.) can be configured on this page. Options • Enable Virtual Space Allows the cursor to move into empty areas. • Enable Auto Indent Automatically indents the next line. • Enable Backspace at Start of Line Will not stop the backspace at the left-most position, but will continue at the end of the previous line. • View blanks and tabs Shows these spaces. • Show Selection Margin Provides a column on the left side where bookmarks and other markings are shown. • Show line Numbers Shows line numbers. • Tab Size Defines the width of a single tab. Tabs Toggles between the use of standard tabs, or to insert spaces when the tab-key is used. Language colouring Defines the syntax-highlighting used when the type of text is not known. ShortCuts Opens the short-cut definition dialogue.

7.8

StationWare

When working with DIgSILENT Šs StationWare , connection options are stored in the user settings.The connection options are as follows: DIgSILENT PowerFactory 15, User Manual

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CHAPTER 7. USER SETTINGS Service Endpoint Denotes the StationWare server name. This name resembles a web page URL and must have the form: • http://the.server.name/psmsws/psmsws.asmx or • http://192.168.1.53/psmsws/psmsws.asmx http denotes the protocol, the.server.name is the computer name (or DNS) of the server computer and psmsws/psmsws.asmx is the name of the StationWare application. Username/Password Username and Password have to be valid user account in StationWare . A StationWare user account has nothing to do with the StationFactory user account. The very same StationWare account can be used by two different PowerFactory users.The privileges of the StationWare account actually restrict the functionality. For device import the user requires read-access rights. For exporting additionally writeaccess rights are required.

7.9

Advanced Options

Contingency Analysis A confirmation dialogue is showed when the Remove Contingencies option is selected in the Contingency Analysis dialogue.

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Part III

Handling

Chapter 8

Basic Project Definition The basic database structure in PowerFactory and the data model used to define and study a power system is explained in Chapter 4 (PowerFactory Overview). It is recommended that users become familiar with this chapter before commencing project definition and analysis in PowerFactory . This Chapter describes how to define and configure projects, and how to create grids.

8.1

Defining and Configuring a Project

There are three methods to create a new project. Two of them employ the Data Manager window and the third the main menu. Whichever method is used, the end result will be the same, a project object in the data base. Method 1 - Using the Main Menu: • On the Main Menu choose File → New→ Project. • Enter the name of the project. Make sure that the ’Target Folder’ points to the folder in which you want to create the project (By default it is set to the active user account folder). • Press Execute. Method 2 - Using the Element Selection Dialogue from the Data Manager: • In the Data Manager press on the New Object button (

)

• In the field at the bottom of the New Object window type IntPrj (after selecting the option ’Others’ in the Elements field). Note that the names in PowerFactory are case-sensitive. • Press Ok. The window that opens next is the edit dialogue of the project folder. Press Ok. Method 3 - Direct from the Data Manager: • Locate the active user in the left-hand portion of the Data Manager. • Place the cursor on the icon of the active user or a folder within the active user account and right-click. • From the context sensitive menu choose New → Project. Press Ok. The window that opens next is the edit dialogue of the project folder. Press Ok. DIgSILENT PowerFactory 15, User Manual

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Note: The ComNew command is used to create objects of several classes. To create a new project it must be ensured that the ’Project’ option is selected.

In order to define and analyze a power system, a project must contain at least one grid and one study case. After the new project is created (by any of the presented methods), a new study case is automatically created and activated. A dialogue used to specify the name and nominal frequency of a new automatically created grid pops up. As the button OK is pressed in the grid edit dialogue: • The new grid folder is created in the newly created project folder. • An empty single line diagram associated to the grid is opened. The newly created project has the default folder structure shown in 8.1.1. Although a grid folder and a study case are enough to define a system and perform calculations, the new project may be expanded by creating library folders, extra grids, variations, operation scenarios, operational data objects, extra study cases, graphic windows, etc. Projects can be deleted by right clicking on the project name on the data manager and selecting Delete from the context sensitive menu. Only non active projects can be deleted. Note: The default structure of the Project folder is arranged to take advantage of the data model structure and thus the user is advised to keep to this pre-determined data structure, at least at first until sufficient experience in using PowerFactory is gained. As may be inferred, the user is not limited to the pre-determined structure and may create, within certain limits, their own project structure for advanced or particular studies.

Figure 8.1.1: Default Project Structure

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8.1.1

The Project Edit Dialogue

The project dialogue of 8.1.2 pops up when selecting Edit → Project. . . on the main menu or when right-clicking the project folder in the Data Manager and selecting Edit from the context sensitive menu. The ’Basic Data’ page, allows the edition of basic project settings and the creation of new study cases and grids: button at the ’Project Settings’ field opens a dialogue where the validity period of • Pressing the the project, the input units to be used within the project (unit system and the decimal prefixes for the adaptable element input dialogues within the project) and the calculation settings (the base apparent power and the minimal value of the resistances and conductances in p.u) are defined. • Pressing the New Grid button will create a new grid and will open the grid edit dialogue. A second dialogue will ask for the study case to which the new grid folder will be added. For additional information about creating a new grid please refer to Section 8.2(Creating New Grids). • The New Study Case button will create a new study case and will open its dialogue. The new study case will not be activated automatically. For further information about creating study cases please refer to Chapter 11: Study Cases, Section 11.2 (Creating and Using Study Cases). • When a project is created, its settings (i.e.the result box definitions, the reports definitions, the flexible page selectors, etc.) are defined by the ’default settings’ from the system library. If these settings are changed, the changes are stored in the Settings folder of the project. The settings from another project or the original (default) ones can be taken by using the buttons Take from existing Project or Set to default in the ’Changed Settings’ field of the edit dialogue. The settings can only be changed when a project is inactive. • The name of the active study case is shown in the lower part of the dialogue window under the ’Active Study Case’ assignment, it’s edit dialogue can be opened by pressing the button.

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Figure 8.1.2: The project dialogue • Pressing the Contents button on the dialogue will open a new data browser displaying all the folders included in the current project directory. The ’Sharing’ page of the dialogue allows the definition of the project sharing rules. This function is especially suitable when working in a multiple user database environment, further information is given in Chapter 18 (Data Management). The ’Derived Project’ page provides information when the project is a derived project of a master project. The ’Storage’ page provides information about the stored data inside the project. The ’Description’ page, like all object’s description pages is used to add user comments and the approval status.

8.1.2

The Project Overview Window

The Project Overview window is illustrated in figure 8.1.3. It is a dockable window, displayed by default on the left side of the main application window between the main toolbar and the output window. It displays an overview of the project allowing the user to assess the state of the project at a glance and facilitating easy interaction with the project data. The window is docked by default, but can be undocked by the user and displayed as a floating window that can be placed both inside and outside of the main application window. If required, the window can be closed by the user. To close or reopen the window the user should deselect or select the option Window → Dock Output Window. . . from the main menu. Only one window can be open at a time. 66

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Figure 8.1.3: The project Overview Window

The following objects and information can be accessed via the project window. • Study Cases – Active Study Case – Inactive Study Cases – Current Study Time • Operation Scenarios – Active Scenario Schedulers – Active Scenarios – Inactive Scenarios • Variations – Recording Expansion Stage – List of active Variations with active Expansion Stages as children – List of inactive Variations with inactive Expansion Stages as children • Grid/System Stages – List of active Grids or System Stages – List of active Grids or System Stages • Trigger – Active triggers Entries for active objects are displayed with bold text, entries for inactive objects (where currently no object is active, but inactive objects exist) are displayed as disabled/grey. A context sensitive menu can be accessed by right clicking on each of the tree entries. The following actions are available for each of the entries: DIgSILENT PowerFactory 15, User Manual

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CHAPTER 8. BASIC PROJECT DEFINITION • Change active item(s): Activate, Deactivate, Change active • Show all available items • Edit (open dialogue) • Edit and Browse • Delete • Save (for Operation Scenario only)

8.1.3

Project Settings

In the Project Settings you can set up the Validity Period of the Project, the method used for Calculation of symmetrical components for untransposed lines, and other settings. The Validity Period of the Project PowerFactory 15 extends the idea of a model into the dimension of time. The Project may span a period of months or even years considering network expansions, planned outages and other system events. The period of validity of a project specifies therefore the time span the network model, which is defined in the Project, is valid for. The Validity Period is defined by Start Time and End Time of the Project (see Figure 8.1.2). The Study Case has got a Study Time, which has to be inside the Validity Period of the Project. To specify the Validity Period of the Project: • Open the Data Manager and browse for the Project folder object (IntPrj). • Right click on it and select Edit from the context sensitive menu. • On the Basic Data tab press the ’Project Settings’ Edit button ( will open.

). The Project Settings dialogue

• On the ’Validity Period’ page adjust the start and end time of the project. • Press OK to accept the changes and close the window. Advanced Calculation Parameters • Auto slack assignment This option has only an influence of the automatic slack assignment (e.g. if no machine is marked as "Reference Machine") – Method 1: all the synchronous machines can be selected as "Slack" (Reference Machine); – Method 2: a synchronous machine is not automatically selected as "Slack" if for that machine the option on load flow page: "Spinning if circuit-breaker is open" is disabled. • Calculation of symmetrical components for untransposed lines The selection of one of these methods defines how the sequence components of lines in PowerFactory will be calculated: – Method 1: apply the 012 transformation (irrespective of line transposition). This is the standard method used; – Method 2: first calculate a symmetrical transposition for untransposed lines, and then apply the 012 transformation.

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8.1.4

Activating and Deactivating Projects

To activate a project use the option File → Activate Project from the main menu. This brings up a tree with all the projects in your user account. Select the project that you want to activate. Alternatively, you may activate a project using the context sensitive menu on the Data Manager. The last 5 active projects are listed at the File field of the main menu bar. The currently active project is the first one in this list. To deactivate the currently active project, select it in the list (left click on it). Alternatively, you may choose the option File → Deactivate Project from the main menu. To activate another project, select it in the list of 5 last active projects. Note: Only one project can be activated at a time.

8.1.5

Exporting and Importing of Projects

Projects (or any folder in the data base) can be exported using the *.dz or the *.pfd (PowerFactory Data) file format. Whenever possible it is recommended to use the new PFD format (*.pfd). This format (*.pfd) is improved for handling even very large projects. The performance of the import/export has been optimized and the consumption of memory resources is much lower than with the old file format (*.dz). All new functions available in the data base of PowerFactory , e.g. time stamps and versions, are fully supported with the new PFD file format. icon To export a project select File → Export. . . → Data. . . from the main menu or by clicking on the of the Data Manager. Alternatively projects can be exported by selecting the option Export. . . on the project context sensitive menu (only available for non active projects). Projects can be imported by selecting File → Import. . . → Data. . . from the main menu or by clicking on the icon of the Data Manager. The user can select the type of file to import from the ’Files of type’ menu of the Windows Open file that pops up. Alternatively projects can be imported by selecting the option Import. . . on the project context sensitive menu (only available for non active projects). Additionally a lot of Import/Export filters are available for foreign data formats.

8.1.6

External References

In order to avoid problems when exporting/importing projects, it is recommended to check for external references before exporting the project. This can be done by selecting the option Check for external References on the project context sensitive menu. If external references are found, these can be packed before exporting by selecting the option Pack external References on the project context sensitive menu. The user can define the source of the External References (i.e. Global Library, Configuration folder, etc). A new folder call "External" containing all the external references will be created inside the Project.

8.2

Creating New Grids

Electrical networks can be defined in PowerFactory using the Graphical Editor or the Data Manager. The graphical method is the simplest one, it just consist in selecting the desired network components from the drawing toolbox and place them in the desired location within the single line graphic. In this case the program automatically creates the network components represented by the graphical objects in the active grids/expansion stages. The connections and the corresponding cubicles are automatically created as the new component is placed (and connected). The use of the data manager requires the DIgSILENT PowerFactory 15, User Manual

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CHAPTER 8. BASIC PROJECT DEFINITION manual definition of the cubicles within the terminals and the selection of the specific cubicle where a branch element is to be connected. This manual definition is more suitable for big networks whose graphical representation becomes complicated. Advanced users may combine both graphical and data manager methods to define and modify their network models more efficiently. Besides explaining the basic methods used to define and edit the network models, this section is intended to explain practical aspects related with the creation and managing of the network grouping objects (reference to grouping objects). The procedures used to create and manage additional network diagrams are also presented here. Information about defining and working with variations and variations stages will be given in a separate section. To start with the description of the network model definition, a description of how new grid folders are created is required. Note: Experienced users may define networks combining the Data Manager and the Graphical Editor. A good practice is to create and connect the network components in the single line graphic and multi edit them in the Data Manager.

To add a grid folder to the current network model, various methods may be employed: 1. Select Edit → Project on the main menu. This will open the dialogue of the project that is currently active. Press the New Grid button. 2. Select Insert → Grid . . . on the main menu. 3. Right-click the project folder in a data manager and select Edit. Press the New Grid button. 4. Right-click the Network Data folder (of the active project) in a data manager window and select New → Grid from the context sensitive menu. The dialogue to create a new grid will pop up after the indicated actions are performed. There the grid name, the nominal frequency and a grid owner (optional) may be specified. A second dialogue will appear after the Ok button has been pressed, here the study case that the grid will be linked to must be selected. Three options are presented: 1. add this Grid/System Stage to active Study Case: Only available when a study case is active. 2. activate a new Study Case and add this Grid/System Stage: Creates and activates a new study case for the new grid. 3. activate an existing Study Case and add this Grid/System Stage: Add the new grid folder to an existing, but not yet active study case. After the Ok button of the second dialogue is pressed, the new grid is created in the Network Model folder and a reference in the Summary Grid object of the selected study case is created. Normally, the second option is preferred because this creates a new study case, dedicated to the new grid only. In that way, the new grid may be tested separately by load-flow or other calculations. To analyze the combination of two or more grids, new study cases may be created later on, or the existing ones may be altered. As indicated in Chapter 11(Study Cases), grids can be added or removed from the active study case afterwards by right clicking and selecting Add/Remove from Active study case.

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Chapter 9

Network Graphics (Single Line Diagrams) 9.1

Introduction

PowerFactory works with three different classes of graphics which constitute the main tools used to design new power systems, controller block diagrams and displays of results: • Single Line Diagrams (described in this chapter) • Block Diagrams (described in Section 26.8: Models for Stability Analysis) • Virtual Instruments (described in Section 17.5: Virtual Instruments) Diagrams are organized in Graphic Boards for visualization (see Section 9.5.2 for more information).

9.2

Defining Network Models with the Graphical Editor

In this section it is explained how the tools of the Graphical Editor are used to define and work with network models.

9.2.1

Adding New Power System Elements

Drawing power system elements is a simple matter of choosing the required element representation in the Drawing Toolbox located in the right hand pane of the PowerFactory GUI. Input parameters of the element are edited through the element and type dialogue. Complete information about the element and type parameters are given in the Appendix C Technical References of Models. To create a new power system element, select the corresponding button in the Drawing Toolbox. This toolbar is only visible to the user when a project and study case is active and the open graphic is unfrozen by deselecting the Freeze Mode button ( ). As the cursor is positioned over the drawing surface, it will have a symbol of the selected tool ’attached’ to it, showing that the cursor is, for example, in ’Terminal’ drawing mode (to reset the mode either press the one of the cursor icons (rectangular or free-form selection) or press ESC or right-click with the mouse). Power system elements are placed and connected in the single line graphic by left clicking on empty places on the drawing surface (places a symbol), and by left clicking nodes (makes a connection). If DIgSILENT PowerFactory 15, User Manual

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CHAPTER 9. NETWORK GRAPHICS (SINGLE LINE DIAGRAMS) wishing to stop the drawing and connecting process press the Escape key or right click at the mouse. There are basically three ways of positioning and connecting new power system elements: 1. By left clicking on one or more nodes to connect and position the element directly. Single port elements (loads, machines) will be positioned directly beneath the nodes at a default distance (the symbol can later be moved if required). Double or triple port objects (transformers) will be centered between the first two terminal connections automatically. 2. By first left clicking on an empty place to position the symbol and then left clicking a node to make the connections. 3. By first left clicking on an empty place, consequently clicking on the drawing surface to define a non-straight connection line and finally clicking on a terminal to make the connection. Note: Nodes for connecting branches are usually defined before placing them on the single line diagram. However, it is possible to place ’connection free’ branch element on the single line diagram by pressing the Tab key once for each required connection (e.g. twice for a line, three times for a three winding transformer)

Figure 9.2.1 shows an example of a generator placed according to the first method (left generator), one placed according to the second method (middle generator), and one placed according to the third method (right generator with long connection).

Figure 9.2.1: Illustration of graphical connection methods

If a load or machine is connected to a terminal using the first method (single left click on busbar), but a cubicle already exists at that position on the busbar, the load or machine symbol will be automatically positioned on the other side of the terminal, if possible. Note: By default all power system elements are positioned “bottom down". However, if the Ctrl key is pressed when the graphic symbol is positioned onto the drawing surface, it will be positioned either turned 90 degrees (terminals) or 180 degrees (edge elements). If the element has already been placed and the user wishes to flip it to the other side of the terminal, it can be done by selecting the element and the right-click → Flip At Busbar.

Once drawn, an element can be rotated by right-click and selecting from the Rotate commands. Figure 9.2.2 shows an example of rotated and flipped power system elements.

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Figure 9.2.2: Flipped and rotated power system elements

The connection between edge elements and terminals is carried out by means of cubicles. When working with the graphical editor, the cubicles are automatically generated in the corresponding terminal. Note: When connections to terminals are defined with switch elements of the class ElmCoup (circuit breakers), cubicles without any additional switches (StaSwitch) are generated.

9.2.2

Drawing Nodes

When commencing a single line diagram, it is common to first place the required nodes / terminals (ElmTerm) on the graphic. There are several symbol representations available for busbar type terminals, from the drawing toolbox on the right-hand pane of the PowerFactory GUI. Busbar This is the most common representation of a node. Busbar (Short) Looks the same as a Busbar but is shorter and the results box and name is placed on the “Invisible Objects" layer by default. Typically used to save space or to unclutter the graphic. Junction / Internal Node Typically used to represent a junction point, say between an overhead line and cable. The results box and name is placed on the “Invisible Objects" layer by default. Busbar (rectangular) Typically used for reticulation and / or distribution networks. Busbar (circular) Typically used for reticulation and / or distribution networks. Busbar (polygonal) Typically used for reticulation and / or distribution networks. Busbars (terminals) should be placed in position and then, once the cursor is reset, dragged, rotated and sized as required. Re-positioning is performed by first left clicking on the terminal to mark it, and then click once more so that the cursor changes to . Hold the mouse button down and drag the terminal to a new position. Re-sizing is performed by first left clicking on the terminal to mark it. Sizing handles appear at the ends.

9.2.3

Drawing Branch Elements

Single port elements (loads, machines, etc.) can be positioned in two ways. The simplest method is to select the symbol from the toolbar and then left click the busbar where the element is to be placed. This will draw the element at a default distance under the busbar. In case of multi busbar systems, only DIgSILENT PowerFactory 15, User Manual

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CHAPTER 9. NETWORK GRAPHICS (SINGLE LINE DIAGRAMS) one of the busbars need be left-clicked. The switch-over connections to the other busbars will be drawn automatically. The ’free-hand’ method first places the element symbol wherever desired, that is, first click wherever you wish to place the symbol. The cursor now has a ’rubber band’ connected to the element (i.e. a dashed line), left-clicking on another node will connect it to that node. To create corners in the joining line left click on the graphic. The line will snap to grid, be drawn orthogonally, as determined by the “Graphic Options" that have been set. Double port elements (lines, transformers, etc.) are positioned in a similar manner to single port symbols. By left-clicking the first busbar, the first connection is made. The second connection line is now held by the cursor. Again, left-clicking the drawing area will create corners. Double-clicking the drawing area will position the symbol (if not a line or cable - e.g. a transformer). The second connection is made when a node is left clicked. Triple port elements (e.g. three-winding transformers) are positioned in the same manner as two port symbols. Clicking the first, and directly thereafter the second node, will place the symbol centered between the two nodes, which may be inconvenient. Better positioning will result from left clicking the first busbar, double-clicking the drawing space to position the element, and then making the second and third connection. The ’free-hand’ method for two and triple port elements works the same as for one port elements. Note: Pressing the Tab key after connecting one side will leave the second leg unconnected, or jump to the third leg in the case of three port elements (press Tab again to leave the third leg unconnected). Pressing Esc or right-click will stop the drawing and remove all connections. If the element being drawn seems as if it will be positioned incorrectly or untidily there is no need to escape the drawing process, make the required connections and then right-click the element and Redraw the element whilst retaining the data connectivity.

Annotations are created by clicking one of the annotation drawing tools. Tools are available for drawing lines, squares, circles, pies, polygons, etc. To draw these symbols left click at on an empty space on the single line diagram and release the mouse at another location (e.g. circles, lines, rectangles). Other symbols require that you first set the vertices by clicking at different positions and finishing the input mode by double-clicking at the last position. For further information on defining lines, see section 9.3 (Defining and Working with Lines and Cables).

9.2.4

Marking and Editing Power System Elements

To mark (select) a power system element click on it with the cursor. The element is then highlighted and becomes the “focus" of the next action or command. The element can be un-marked or de-selected by clicking on another element or by clicking onto some free space in the graphic.

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(a) Freeze Mode

(b) Unfreeze Mode

Figure 9.2.3: Marking/ Selecting elements

The element is highlighted with a different pattern depending on whether the graphic has been frozen or not, as seen in Figure 9.2.3, where 9.2.3a is the when the Freeze Mode is selected and 9.2.3b when Freeze Mode is deselected. There are different ways to mark several objects at once: • To mark all graphical elements, press the All button ( be used.

). The keyboard short cut Ctrl+A may also

• To mark a set of elements at the same time click on a free spot in the drawing area, hold down the mouse key and move the cursor to another place where you release the mouse button. All elements in the so defined rectangle will now be marked. A setting, found in the User Settings dialogue under the ’Graphic Windows’ page, on the Advanced tab, can alter the manner in which objects are marked using this marking method, as either ’Partial’ or ’Complete’. ’Complete’ means that the whole object marked must lie inside the rectangle. • To mark more than one object, hold down the Ctrl key whilst marking the object. • When clicking on an element and clicking on this element a second time whilst holding down the Alt key will also mark all the elements connected to the first element. • In PowerFactory it is possible to place a terminal on an existing line in the single line diagram by placing the terminal on the line itself. Moving the terminal to a different location on the single line diagram may move line sections in an undesirable manner. By holding the Ctrl+Alt keys whilst moving the terminal, the line sections will not be moved. However, note that this does not change the actual location of the terminal along the line. The data of any element (its edit dialogue) may be viewed and edited by either double-clicking the graphic symbol under consideration, or by right-clicking it and selecting Edit Data. When multiple objects are selected, their data can be viewed and edited trough a data browser by right-clicking the selection and choosing Edit Data from the context sensitive menu. Note: Finding specific elements in a large project may be difficult if one had to look through the single line diagram alone. PowerFactory includes the Mark in Graphic tool, to assist the user in finding elements within the graphic. The user has to first search for the desired object in the Data Manager using any of the methods presented in Chapter 10 (Data Manager). Once a searched object is identified, it may be right-clicked and the option Mark in Graphic selected.

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9.2.5

Interconnecting Power Subsystems

Interconnections between two different graphics can be achieved using two methods: 1. Representing a node in additional different graphics by copying and pasting the graphic only and then by connecting branch and edge elements to the graphical object in the additional graphic. This is performed by copying the desired node (right-click → Copy ) and then clicking on the other graphic in which it should be represented and right-click → Paste Graphic Only. Only a graphical object is pasted into the second graphic and no new data element is created. 2. Ensure that there is a node to connect to in the graphics that are to be interconnected. Then connect an edge element between the two graphics. Example In this example a line will be used to interconnect two regions according to the second method. 1. Select a line drawing tool from the toolbar and create the first connection as normal by left clicking a node (see Figure 9.2.4). 2. Double-click to place the symbol. Your cursor is now attached to the line by a ’rubber band’. Move the cursor to the bottom of the drawing page and click on the tab of the graphic that the interconnection is to be made to (see Figure 9.2.5). 3. Once in the second graphic left click to place the line symbol (see Figure 9.2.6) and then left click on the second node. The interconnected leg is shown by an next page option.

symbol. Right-clicking on the element presents a Jump to

Figure 9.2.4: First step to interconnecting

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Figure 9.2.5: Second step to interconnecting

Figure 9.2.6: Third step to interconnecting Note: The first method of interconnection, that of representing a node in two, or more, different graphics, may lead to confusion at a later point as the ’inflow’ and ’outflow’ to the node will not appear correct when just one graphic is viewed - especially if a user is not familiar with the system. The node may be right-clicked to show all connections in what is known as the ’Station Graphic’ (menu option Show station graphic). Thus, the second method may be preferred. To check for nodes that have connections on other graphics the “Missing graphical connections" diagram colouring may be employed.

9.2.6

Working with Substations in the Graphical Editor

Substations and Secondary Substations from existing templates are created using the network diagrams. The substations are represented in these diagrams by means of composite node symbols. Creating a New Substation in an Overview Diagram Overview diagrams are single line diagrams without detailed graphical information of the substations. Substations and Secondary Substations are illustrated as “Composite Nodes", which can be coloured DIgSILENT PowerFactory 15, User Manual

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CHAPTER 9. NETWORK GRAPHICS (SINGLE LINE DIAGRAMS) to show the connectivity of the connected elements (“Beach Ball"). Substations and Secondary Substations from pre-defined templates (or templates previously defined by the user) are created using the network diagrams. The substations are represented in these diagrams by means of composite node symbols. To draw a substation from an existing template in an overview diagram: or ) for Substations or ( • Click on the symbol of the composite node ( Substations listed among the symbols on the right-hand drawing pane.

) for Secondary

• Select the desired substation template from the list. • Click on the overview single line diagram to place the symbol. The substation is automatically created in the active grid folder. • Right click the substation, select Edit Substation, and rename the substation appropriately. • Close the window with the templates. • Press Esc or right click on the mouse to get the cursor back. • Resize the substation symbol in the overview diagram to the desired size. A diagram of the newly created substation can be opened by double clicking at the composite node symbol. In the new diagram it is possible to rearrange the substation configuration and to connect the desired components to the grid. To resize a composite node: • Click once on the composite node you want to resize. • When it is highlighted, place the cursor on one of the black squares at the corners and hold down the left mouse button. • A double-arrow symbol appears and you can resize the figure by moving the mouse. For a rectangular composite node you can also resize the shape by placing the cursor on one of the sides. For further information on templates please refer to Chapter 12: Project Library, Section 12.4 (Templates Library). To show the connectivity inside a composite node: Press the button to open the colouring dialog. Select the ’Function’ for which the colouring mode is relevant (for example, select the ’Basic Data’ tabpage). Under ’Other’ select ’Topology’, and then ’Station Connectivity’. There are two ways to open the graphic page of a substation. The first is to double-click on the corresponding composite node in the overview diagram. The second is to go to the graphic object of the substation in the data manager, right-click and select Show Graphic. Details of how to define templates are provided in Chapter 12 (Project Library). Substation Switching Rules Switching Rules ( ) (IntSwitching) store switching actions for a selected group of switches that are defined inside a substation. The different switching actions (no change, open or close) are defined by the user considering different fault locations that can occur inside a substation. By default, the number of fault locations depends on the number of busbars and bay-ends contained inside the substation; although the user is allowed to add (and remove) specific fault locations and switches belonging to the substation. The switch actions will always be relative to the current switch positions of the breakers. 78

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9.2. DEFINING NETWORK MODELS WITH THE GRAPHICAL EDITOR The selection of a Switching Rule for a substation is independent of the selection of a Running Arrangement and if required, the reference to the switching rule in a substation can be stated to be operational data; provided the user uses the Scenario Configuration object. For more information on the scenario configuration refer to Chapter 14 (Operation Scenarios). A typical application of Switching Rules is in contingency analysis studies, where there is a need to evaluate the contingency results considering the “actual" switch positions in a substation and compare them to the results considering a different substation configuration (for the same contingency). To create a switching rule To create a new Switching Rule: • Edit a Substation, either by right-clicking on the substation busbar from the single line graphic, and from the context-sensitive menu choosing Edit a Substation, or by clicking on an empty place in the substation graphic, and from the context-sensitive menu choosing Edit Substation. This will open the substation dialogue. • Press the Select button (

) in the Switching Rule section and select New. . .

• The new Switching Rule dialogue pops up, where a name and the switching actions can be specified. The switching actions are arranged in a matrix where the rows represent the switches and the columns the fault locations. By default the fault locations (columns) correspond to the number of busbars and bay-ends contained inside the substation, while the switches correspond only to the circuit breakers. The user can nevertheless add/remove fault locations and/or switches from the Configuration page. The switch action of every defined breaker in the matrix can be changed by double clicking on the corresponding cell, as illustrated in Figure 9.2.7. Press afterwards Ok. • The new switching rule is automatically stored inside the substation element.

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Figure 9.2.7: Switching Rule Dialogue

To select a Switching Rule A Switching Rule can be selected in the Basic Data page of a substation dialogue (ElmSubstat) by: • Opening the substation dialogue. • Pressing the Select button ( ) in the Switching Rule section. A list of all Switching Rules for the current substation is displayed. • Selecting the desired Switching Action. To apply a Switching Rule A Switching Rule can be applied to the corresponding substation by pressing the Apply button from within the switching rule dialogue. This will prompt the user to select the corresponding fault locations (busbars) in order to copy the statuses stored in the switching rule directly in the substation switches. Here, the user has the option to select either a single fault location, a group or all of them. The following functional aspects must be regarded when working with switching rules: • A switching rule can be selected for each substation. By default the selection of a switching rule in a substation is not recorded in the operation scenario. However, this information can defined as part of an operational scenario by using the Scenario Configuration object (see Chapter 14: Operation Scenarios).

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9.2. DEFINING NETWORK MODELS WITH THE GRAPHICAL EDITOR • If a variation is active the selection of the Switching Rule is stored in the recording expansion stage; that is considering that the Scenario Configuration object hasn’t been properly set. To assign a Switching Rule The Assign button contained in the switching rule dialogue allows to set it as the one currently selected for the corresponding substation. This action is also available in the context-sensitive menu in the data manager (when right-clicking on a switching rule inside the data manager). To preview a Switching Rule The Preview button contained in the switching rule dialogue allows to display in a separate window the different switch actions for the different fault locations of the corresponding substation.

9.2.7

Working with Composite Branches in the Graphical Editor

New composite branches can be created in the Data Manager using the procedure described in Chapter 10, Section 10.3.4 (Defining Composite Branches in the Data Manager). The definition and connection of the branch components can then be carried out in the relevant single line diagram, which is automatically generated after the creation of the new branch. Branches from previously defined templates are created using the single line diagram. The branches are represented in these diagrams by means of the Composite Branch symbol ( ). To create a new branch from a template: • Click on the Composite Branch button ( ) listed among the symbols on the right-hand drawing pane. A list of available templates (from the Templates library) for branches will appear. If only one Branch template exists, no list is shown. • From this list choose the template that you want to create the branch from. • If the branch is to be connected with terminals of the same single line graphic, simply click once on each terminal. • If the branch is to be connected with a terminal from another single line diagram, you have to ’Paste graphically’ one of the terminals on the diagram where you want to represent the branch, or connect across pages as discussed in section 9.2.5 (Interconnecting Power Subsystems). • If the branch is to be connected with terminals from a substation, click once on each composite node to which the branch is to be connected. You will be automatically taken inside each of those composite nodes to make the connections. In the substation graphic click once on an empty spot near the terminal where you want to connect the branch end, and then on the terminal itself. A diagram of the newly created branch can be opened by double clicking at the composite branch symbol. In the new diagram it is possible to rearrange the branch configuration and to change the branch connections. Details of how to define templates are provided in Chapter 12 (Project Library).

9.2.8

Working with Single and Two Phase Elements

It is possible to define the phase technology of elements such as terminals, lines, and loads. In instances where the number of phases of a connecting element (e.g. a circuit breaker or line) is equal to the number of phases of the terminal to which it connects, PowerFactory will automatically assign the connections. However, when connecting single-phase elements to a terminal with greater than one phase, or two-phase elements to terminals with greater than three phases, it is sometimes necessary to DIgSILENT PowerFactory 15, User Manual

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CHAPTER 9. NETWORK GRAPHICS (SINGLE LINE DIAGRAMS) adjust the phase connectivity of the element to achieve the desired connections. The phase connectivity can be modified as follows: • Open the dialogue window of the element (by double-clicking on the element). • Press the Figure >> button to display a figure of the elements with its connections on the bottom of the dialogue window. • Double-click on the dark-red names for the connections inside this figure. • Specify the desired phase connection/s. Alternatively, click the right arrow ( tion/s.

) next to the Terminal entry and specify the desired phase connec-

Note: It is possible to colour the grid according to the phases (System Type AC/DC and Phases). For more information about the colouring refer to Section 9.7.6 (Graphic Attributes and Options).

9.3

Defining and Working with Lines and Cables

This section describes specific features and aspects of line and cable data models used in PowerFactory . Detailed technical descriptions of the models are provided in Appendix C (Technical References of Models). In PowerFactory , lines and cables are treated alike, they are both instances of the generalized line element ElmLne. A line may be modelled simply as a point-to-point connection between two nodes and will refer to a line (TypLne), tower (TypTow), a tower geometry (TypGeo), a line coupling (ElmTow), or a cable system coupling (ElmCabsys) type. Alternatively, lines may be subdivided into sections referring to different types. Note: Anywhere that ’line’ is written in this section, ’lines and/or cables’ may be read, unless otherwise specified.

The two basic line configurations are depicted in Figure 9.3.1: 1. Top line: the simplest line is a single line object (ElmLne). 2. Bottom line: such a single line may be subdivided into line section objects (ElmLnesec) at any time/location. No terminals are allowed between two sections, but the sections may have different line types.

Figure 9.3.1: Basic line configurations

The purpose of separating lines into sections is to obtain different line parts, with different types (such as when a line uses two or more different tower types, or when manual transpositions should be modelled - since the “Transposed" option in the type object is a perfect, balanced, transposition). 82

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9.3. DEFINING AND WORKING WITH LINES AND CABLES

9.3.1

Defining a Line (ElmLne)

The simplest line model is a point-to-point connection between two nodes. This is normally done in the single line graphic by selecting the ( ) icon and by left clicking the first terminal, possibly clicking on the drawing surface to draw a corner in the line and ending the line at the second terminal by left clicking it. This will create an ElmLne object in the database. When this object is edited, the following dialogue will appear.

Figure 9.3.2: Editing a transmission line

The dialogue shows the two cubicles to which the transmission line is connected (’terminal i’ and ’terminal j’). The example in Figure 9.3.2 shows a line which is connected between the nodes called ’Line End Terminal’ and ’Line Feeder Bus’ from a grid called ’ North’. The line edit dialogue shows the name of the node (in red) in addition to the name of the cubicle (in blue). The actual connection point to the node is the cubicle and this may be edited by pressing the edit button ( ). The cubicle may be edited to change the name of the cubicle, add/remove the breaker, or change phase connectivity as discussed in section 9.2.8 (Working with Single and Two Phase Elements). The type of the line is selected by pressing the ( are:

) next to the type field. Line types for a line/ line route

• The TypLne object type, where electrical parameters are directly written (the user can select if the type is defined for an overhead line or a cable). • Tower types (TypTow and TypGeo), where geometrical coordinates and conductor parameters are specified, and the electrical parameters are calculated from this data. Selection of the tower type will depend on the user’s requirement to link conductor type data to the line element as in TypGeo (for re-use of the one tower geometry with different conductors), or to link conductor type data to the tower type as in TypTow (for re-use of one tower geometry with the same conductors). Once the lines (or cables) have been created it is possible to define couplings between the circuits that DIgSILENT PowerFactory 15, User Manual

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CHAPTER 9. NETWORK GRAPHICS (SINGLE LINE DIAGRAMS) they are representing by means of line coupling elements ElmTow (for overhead lines) and cable system coupling elements ElmCabsys (for cables). Details of how to create Line Sections, Cable Systems, and Line Couplings are provided in the following sections, and further information about line/cable modelling is given in the respective Technical References.

9.3.2

Defining Line Sections

To divide a line into sections: • Press the Sections/Line Loads button in the line dialogue. This will open a data browser showing the existing line sections (if the line has not been sectioned, it will be empty). • Click on the new object icon (

) and select the element Line Sub-Section (ElmLnesec).

• The edit dialogue of the new line section will pop up. There it is possible to define the type and length of the new section.

9.3.3

Example Cable System

Consider a three-phase underground cable comprised of three single-core cables with sheaths. The cable system is created within the active project by taking the following steps. 1. Create a Single Core Cable Type (TypCab) and Cable Definition Type (TypCabsys): • Navigate to the ’Equipment Type Library’ and select the New Object icon, or on the right-hand side of the data manager right-click and select New → Others. • Select ’Special Types’, ’Single Core Cable Type’, and then Ok. • Enter the Type parameters and select Ok. (Note that in this example, a Sheath is also selected, and therefore a separate line will later be defined in the Network Model to represent the sheath.) • Again select the New Object icon, or on the right hand side of the data manager right-click and select New → Others. • Select ’Special Types’, ’Cable Definition’, and then Ok. • Enter type parameters including ’Earth Resistivity’, and ’Coordinates of Line Circuits’ (note that positive values indicate the depth below the surface). Select the Single Core Cable Type defined in the previous steps and press Ok. 2. Create the Network Model: • Add four terminals in the single line diagram at the same voltage defined in the Single Core Cable Type. • Connect a Line Element between two of the terminals to represent the phase conductors, and enter the element parameters. • Connect another Line Element between the other two terminals to represent the sheath, and enter the element parameters. (Add connections from the sheath terminals to earth as required.) 3. Create a Cable System Element (ElmCabsys): • Create a Cable System by selecting the two lines drawn in the single line diagram (hold down Ctrl and left-click each line). Then right-click one of the lines and select Define → Cable System from the context sensitive menu. Alternatively, define the cable system in the Data Manager by creating a New Object and selecting Other → Net Elements→ Cable System, and then select the required Cable Definition and Line Elements to represent the Conductor and Sheath circuits. 84

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9.3. DEFINING AND WORKING WITH LINES AND CABLES • Select the Cable Definition defined in step 1 and press Ok twice. Note that the steps above could be conducted in an alternative order. For example, item 2 could be completed before 1. Also, item 3 could be completed before item 1, and Cable Types could be created at the time the Cable System Element is created. However, the recommended approach is to first define the Type data that is to be used in the Network Model, then to create the Network Model with particular instances of the cable as in the example. Figure 9.3.3 illustrates the interrelationship between the elements and types used to define cable systems inPowerFactory. Note that by right-clicking the line that represents the sheath and selecting ’Edit Graphic Object’ the Line Style can be modified to indicate graphically that this line represents the sheath.

Figure 9.3.3: Example Cable System DIgSILENT PowerFactory 15, User Manual

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9.3.4

Example Line Couplings

Consider an example where there are two parallel transmission lines, each with a three-phase HV (132 kV) circuit, three-phase MV (66 kV) circuit, and two earth conductors. The tower element is created within the active project by taking the following steps. 1. Create the Conductor Types (TypCon) for phase and earth conductors: • Navigate to the ’Equipment Type Library’ and select the New Object icon, or on the right-hand side of the data manager right-click and select New → Others. • Select ’Special Types’, ’Conductor Type’, and then Ok. • Enter the Type parameters and select Ok. In this example, conductors are defined for HV, MV, and earth conductors. 2. Create a Tower Geometry Type (TypeGeo): • Again select the New Object icon, or on the right hand side of the data manager right-click and select New → Others. • Select ’Special Types’, ’Tower Geometry Type’, and then Ok. • Enter type parameters for the number of Earth Wires and Line Circuits (in this example, two earth wires and two line circuits), and the coordinates of the conductors. 3. Create the Network Model: • Add two HV and two MV terminals in the single line diagram (at voltages consistent with the previously defined conductor types). • Connect two Line Elements between the HV terminals, connect two Line Elements between the MV terminals, and enter element parameters. 4. Create a Line Couplings Element (ElmTow): • Create a Line Coupling by selecting the four lines drawn in the single line diagram (hold down Ctrl and left-click each line). Then right-click one of the lines and select Define → Line Couplings from the context sensitive menu. Alternatively, define the Line Coupling in the Data Manager by creating a New Object and selecting Other → Net Elements→ Line Couplings. • Enter the Number of Overhead Line Systems (in this case, two) select the previously defined tower Geometries, Earth Wires, Circuits, and Types, and enter element parameters such as the Distance between the Towers. • Optionally define a Route so that the single line diagram may be coloured based on the defined Line Couplings and press Ok. Note that the steps above could be conducted in an alternative order. For example, item 3 could be completed before 1 and 2. Also, item 4 could be completed before items 1 and 2, and Conductor Types and Towers could be created at the time the Line Couplings Element is created. However, the recommended approach is to first define the Type data that is to be used in the Network Model, then to create the Network Model with particular instances of the lines/towers as in the example. Figure 9.3.4 illustrates the interrelationship between the elements and types used to define Line Couplings (Tower Elements) in PowerFactory.

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9.4. NEUTRAL WINDING CONNECTION IN NETWORK DIAGRAMS

Figure 9.3.4: Example Tower

9.4

Neutral winding connection in network diagrams

PowerFactory offers the user the option to explicitly represent the neutral connections and interconnections of the following widely used elements: • Power transformers (ElmTr2 and ElmTr3) • Shunt elements (ElmShunt) DIgSILENT PowerFactory 15, User Manual

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CHAPTER 9. NETWORK GRAPHICS (SINGLE LINE DIAGRAMS) • External grids (ElmXnet) • Synchronous (ElmSym) and asynchronous machines (ElmAsm) • Static generators (ElmGenstat) • PV systems (ElmPvsys) • Neutral earthing elements (ElmNec) The interconnection of separate neutral wires is illustrated with the help of the Synchronous Generator. A separate neutral connection can be activated by choosing the option N-Connection on the Zero Sequence/Neutral Connection tab on the basic data page of the element as shown in figure 9.4.1, the graphical symbol of the object will change. An illustration for the the Synchronous Generator element is shown in figure 9.4.2. Please note, once the N-Connection via a separate terminal option is selected, the Vector Groups layer can no longer be hidden in the single line diagram.

Figure 9.4.1: Zero Sequence/Neutral Connection Tap

Figure 9.4.2: Generator with N-Connection via seperate terminal

To connect the neutral of the Element to a neutral busbar, right click on the element and press Connect Element. An example of a single line diagram with the interconnection of neutral wires is shown in figure 9.4.3. A Neutral terminal is configured by ensuring that the Phase Technology of the terminal is set to N as shown in figure 9.4.4.

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9.4. NEUTRAL WINDING CONNECTION IN NETWORK DIAGRAMS

Figure 9.4.3: Grid with neutral winding connection

Figure 9.4.4: Set neutral Terminal

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9.5

Graphic Windows and Database Objects

In the PowerFactory graphic windows, graphic objects associated with the active study case are displayed. Those graphics include single line diagrams, station diagrams, block diagrams and Virtual Instruments. Many commands and tools are available to edit and manipulate symbols in the graphics. The underlying data objects may also be accessed and edited from the graphics, and calculation results may be displayed and configured. Many of the tools and commands are found in the drop down menus or as buttons in the toolbars, but by far the most convenient manner of accessing them is to use the right mouse button to display a menu. This menu is known as a ’Context Sensitive Menu’; PowerFactory evaluates where the tip of your cursor is, and then presents a menu that is appropriate to the cursor location. Thus cursor position is important when selecting various menu options. It is important to keep the cursor in place when right-clicking, as the menu presented is determined from cursor position primarily, and not from the selected or marked object.

9.5.1

Network Diagrams and Graphical Pages

Four types of graphical pages are used in PowerFactory : 1. Single Line Diagrams (network diagrams) for entering power grid definitions and for showing calculation results. 2. Detailed graphics of substations or branches (similar to network diagrams) for showing busbar (nodes) topologies and calculation results 3. Block Diagrams for designing logic (controller) circuits and relays. 4. Virtual Instrument Pages for designing (bar) graphs, e.g. for the results of a stability calculation, bitmaps, value boxes, etc... The icon Graphical Pages ( ) can be found inside the Data Manager. Grids, substations, branches, and controller types (common and composite types in PowerFactory terminology) each have a graphical page. In order to see the graphic on the screen, open a Data Manager and locate the graphic page object you want to show, click on the icon next to it, right-click and select Show Graphic. The “Show Graphic" option is also available directly from each object. So for example you can select a grid in the data manager, right-click, and show the graphic. The graphic pages of grids and substations are to be found in the subfolder Diagrams ( ) under the “Network Model" folder. Note that it is also possible to store Diagrams within the Grid, although this is generally not recommended.

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9.5. GRAPHIC WINDOWS AND DATABASE OBJECTS

Figure 9.5.1: The Diagrams folder inside the Data Manager

9.5.2

Active Graphics, Graphics Board and Study Cases

The graphics that are displayed in an active project are determined by the active study case. The study case folder contains a folder called the ’Graphics Board’ folder (SetDesktop) in which references to the graphics to be displayed are contained. This folder is much like the ’Summary Grid’ folder which is also stored within the Study Case, and links active grids to the Study Case. Both the Graphics Board and Summary Grid are automatically created and maintained and should generally not be edited by the user. Within a PowerFactory project, the Network Model folder contains a sub-folder called Diagrams. This sub-folder should generally also not be edited by the user as it is automatically created and maintained. It contains the objects that represent single line and substation graphics (IntGrfnet objects). More than one graphic (single line or substation diagrams) may be created for a grid, either to display the different grid elements over several pages, or to display the same grid elements in different graphical arrangements. Consider the ’Project’ that is shown in Figure 9.5.2. The active study case is called Study Case_1 and the active grid has three single line graphics that have been created for it, Grid_1, Grid_2 and Grid_3. The graphics board folder in the study case has a reference to only the Grid_1 graphic object and thus only this graphic for the grid will be shown when the study case is activated. In the case of single line graphics, the references in the graphics board folder are created when the user adds a grid to a study case. PowerFactory will ask the user which graphics of the grid should be displayed. At any time later the user may display other graphics by right-clicking the grid and selecting Show Graphic from the context sensitive menu. Graphics may be removed from the active study case by right-clicking the tab at the bottom of the corresponding graphic page and selecting Remove Page(s). The study case and graphics board folder will also contain references to any other graphics that have been created when the study case is active, such as Virtual Instrument Panels.

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Figure 9.5.2: Relationship between the study case, graphics board and single line diagrams

9.5.3

Single Line Graphics and Data Objects

In a simple network there may be a 1:1 relationship between data objects and their graphical representations, i.e. every load, generator, terminal and line is represented once in the graphics. However, PowerFactory provides additional flexibility in this regard. Data objects may be represented graphically on more than one graphic, but only once per graphic. Thus a data object for one terminal can be represented graphically on more than one graphic. All graphical representations contain the link to the same data object. Furthermore, graphical symbols may be moved without losing the link to the data object they represent. Likewise, data objects may be moved without affecting the graphic. The graphics themselves are saved in the database tree, by default in the Diagrams folder of the Network Model. This simplifies finding the correct Single Line graphic representation of a particular grid, even in the case where there are several graphic representations for one grid. When the drawing tools are used to place a new component (i.e. a line, transformer, etc.) a new data object is also created in the database tree. A Single Line Graphic object therefore has a reference to a grid folder. The new data objects are stored into the ’target’ folders that the graphics page are associated with. This information may be determined by right-clicking the graphic → Graphic Options, see Section 10.5 (Editing Data Objects in the Data Manager) for more information. Since data objects may have more than one graphic representation the deletion of a graphic object should not mean that the data object will also be deleted. Hence the user may choose to delete only the graphical object (right-click menu → Delete Graphical Object only ). In this case the user is warned that the data object will not be deleted. This suggests that a user may delete all graphical objects related to a data object, with the data object still residing in the database and being considered for calculations. 92

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9.5. GRAPHIC WINDOWS AND DATABASE OBJECTS When an element is deleted completely (right menu option → Delete Element) a warning message will confirm the action. This warning may be switched off in the User Settings dialogue, General page, “Always confirm deletion of Grid Data").

9.5.4

Editing and Selecting Objects

Once elements have been drawn on the graphic the data for the element may be viewed and edited by either double-clicking the graphic symbol under consideration, or by right-clicking it and selecting Edit Data. The option Edit and Browse Data will show the element in a data manager environment. The object itself will be selected (highlighted) in the data manager and can be double-clicked to open the edit dialogue. A new data manager will be opened if no data manager is presently active. If more than one symbol was selected when the edit data option was selected, a data browser will pop up listing the selected objects. The edit dialogues for each element may be opened from this data browser one by one, or the selected objects can be edited in the data browser directly, see Section 10.5 (Editing Data Objects in the Data Manager). Finding specific elements in a large project may be difficult if one had to look through the single line diagram alone. PowerFactory includes the Mark in Graphic tool, to assist the user in finding elements within the graphic. To use this tool the user has to first search for the desired object in the Data Manager using any of the methods presented in Chapter 10 (Data Manager). Once a searched object/element is identified, it may be right-clicked and the option Mark in Graphic selected. This action will mark the selected object in the single line graphic where it appears. When performing this command ensure that the object itself is selected, as shown in Figure 9.5.3. The menu will be different to that seen when selecting an individual field, as shown in Figure 9.5.4.

Figure 9.5.3: Selecting an object correctly to Mark in Graphic

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Figure 9.5.4: Selecting an object incorrectly to Mark in Graphic Note: The position of an object in the database tree can be found by: -Opening the edit dialogue. The full path is shown in the header of the dialogue. -Right-clicking the object and selecting Edit and Browse. This will open a new database browser when required, and will focus on the selected object.

9.5.5

Creating a New Project

A new project may be created by selecting File → New on the main menu. This creates a new Project folder and a dialogue is displayed where the user can define a grid folder in the Project folder. Finally the Graphic page in which the single line diagram will be displayed.

9.5.6

Creating New Graphic Windows

A new graphic window can be created using the New command dialogue. This dialogue may be opened using one of the following methods: • By pressing the

icon.

• By pressing the keyboard shortcut Ctrl+N. • By selecting from the Insert menu on the main menu. The ComNew dialogue must be configured to create the desired new object and the new object should be named appropriately. Ensure that the correct target folder for the new object is selected. Graphical objects that may be created using this dialogue (DiaPagetyp) are: Grid Creates a new grid folder and a new Single Line Graphic object in that folder. The (empty) single line graphic will be displayed. Block Diagram Creates a new Block Diagram folder in the selected folder and a new Block Diagram Graphic object. The (empty) block diagram graphic will be displayed. 94

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9.5. GRAPHIC WINDOWS AND DATABASE OBJECTS Virtual Instrument Panel Creates a new Virtual Instrument Page object. The (empty) Virtual Instrument Page will be displayed. Single Line Diagram Creates a Single Line Graphic in the target folder. Before the graphic is inserted, the user is prompted to select the relevant grid. The target folder will be set to the ∖User folder by default, but may be changed to any folder in the database tree. The new grid, Block Diagram or Virtual Instruments folder will be created in the target folder. In all cases, a new graphics board object is also created, because graphic pages can only be shown as a page in a graphics board. An exception is the creation of a new page, while in a graphics board. This icon on the graphics board toolbar. This will add the new graphics page can be done by pressing the to the existing graphics board. Further information about how to draw network components is given in the following sections.

9.5.7

Basic Functionality

Each of the four graphic window types are edited and used in much the same way. This section gives a description of what is common to all graphic windows. Specific behaviour and functionality of the graphic windows themselves are described other sections of the manual.

9.5.8

Page Tab

The page tab of the graphic window displays the name of the graphics in the graphics board. The sequence of the graphics in the graphics board may be changed by the user. A page tab is clicked and moved by dragging and dropping. An arrow marks the insert position during drag and drop. Another way to change the order of the graphics is to select the option Move/Copy Page(s) of the context sensitive menu. In addition virtual instrument panels can be copied very easily. To do so the Ctrl key is pressed during drag and drop. The icon copies a virtual instrument panel and inserts the copy alongside the original panel. The page tab menu is accessed by a right-click on the page tab of the graphic windows. The following commands are found: • Insert Page → Create New Page creates a new page (the

icon in the toolbar will do the same).

• Insert Page → Open Existing Page opens a page or graphic that has already been created but which is not yet displayed (the icon in the toolbar will do the same). • Rename Page presents a dialogue to change the name of the graphic. • Move/Copy Page(s) displays a dialogue to move or copy the selected page. Copy is only available for virtual instrument panels.

9.5.9

Drawing Toolboxes

Each graphics window has a specific Drawing Tool Box. This toolbox has buttons for new network symbols and for non-network symbols. See Figure 9.5.5 for two examples.

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(a) Single Line Diagrams

(b) Block Diagrams

Figure 9.5.5: Drawing Toolbox examples

The toolboxes have: • Network or block diagram symbols, which are linked to a database object: terminals, busbars, lines, transformers, switches, adders, multipliers, etc. • Graphical add-on symbols: text, polygons, rectangles, circles, etc. The toolboxes are only visible when the graphics freeze mode is off. The graphics freeze mode is turned on and off with the icon (found at the main icon bar of the graphical window).

9.5.10

Active Grid Folder (Target Folder)

On the status bar of PowerFactory (Figure 9.5.6), the active grid folder is displayed on the left-most field, indicating the target folder (grid) that will be modified when you make changes in the network diagram. To change the active target folder, double-click this field and then select the desired target folder. This can be useful if the user intends to place new elements on a single line diagram, but have the element stored in a different grid folder in the data manager.

Figure 9.5.6: The Status Bar

9.6

Drawing Diagrams with Existing Network Elements

This section provides information about how to draw network components from existing objects. Designing new (extensions to) power system grids, is preferably done graphically. This means that the new power system objects should be created in a graphical environment. After the new components 96

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9.6. DRAWING DIAGRAMS WITH EXISTING NETWORK ELEMENTS are added to the design, they are edited, either from the graphical environment itself (by double-clicking the objects), or by opening a database manager and using its editing facilities. It is however possible, to first create objects in the database manager (either manually, or via import from another program), and subsequently draw these objects in one or more single line diagrams. PowerFactory allows for this either by drag and drop facilities to drag power system objects from the data manager to a graphic window, or by the ’Draw Existing Net Elements’ tool. The way this is done is as follows: 1. Select from the drawing tools toolbox the type of object that is to be drawn in the graphic. 2. Enable the drag & drop feature in the data manager by double-clicking the drag & drop message in the message bar. 3. Select the data object in the data manager by left clicking the object icon. 4. Hold down the left mouse button and move the mouse to the graphic drawing area (drag it). 5. Position the graphical symbol in the same way as is done normally. 6. A new graphical symbol is created, the topological data is changed, but the graphical symbol will refer to the dragged data object. No new data object is created. The Draw Existing Net Elements tool may also be used to perform this action, as described in the next sections.

9.6.1

Drawing Existing Busbars

Click on the button Drawing existing Net Elements ( ) and a window with a list of all the terminals (busbars) in the network that are not visualized in the active diagram will appear. Click on the symbol for busbars ( attached to the cursor.

) in the drawing toolbox. The symbol of the busbar (terminal) is now

If the list is very large, press the button Adjacent Element Mode ( ), and then right-click an existing node in the single line diagram and select ’Set as starting node’. This activates the selecting of distance (number of elements) from elements in the active node. Select the Distance of 1 in order to reduce the number of busbars (terminals) shown. If the button Use drawn nodes as starting objects ( all drawn nodes (not just a single starting node).

) is also selected, the list will be filtered based on

If Show elements part of drawn composite nodes ( ) is selected, elements internal to already drawn composite nodes will be shown in the list. However, since they are already drawn as part of the composite node, they should not be re-drawn. The marked or selected element can now be visualized or drawn by clicking somewhere in the active diagram. This element is drawn and disappears from the list. Note that the number of elements in the list can increase or decreases depending on how many elements are a distance away from the element lastly drawn. Scroll down the list, in case only certain elements have to be visualized. Close the window and press Esc to return the Cursor to normal. The drawn terminals (busbars) can be moved, rotated or manipulated in various ways.

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9.6.2

Drawing Existing Lines, Switches, and Transformers

Similar to the busbars, elements like lines and transformers connecting the terminals in the substation can be drawn. Press the button Draw Existing Net Elements ( ). For lines select the line symbol ( toolbox, for transformers select the transformer symbol ( ), and so on.

) from the drawing

Similar to terminals, a list of all the lines (or transformers, or elements which have been chosen) in the network, that are not in the active diagram are listed. Reduce the list by pressing the button Elements which can be completely connected ( ) at the top of the window with the list. A list of lines with both terminals in the active diagram is pre-selected. If the list is empty, then there are no lines connecting any two unconnected terminals in the active diagram. For each selected line (or transformers...) a pair of terminals, to which the line is connected is marked in the diagram. Click on the first terminal and then on the second. The selected line is drawn and is removed from the list of lines. Continue drawing all lines (or transformers...), until the list of lines is empty or all the lines to be drawn have been drawn. If a branch cannot be completely drawn (for example, when the terminal at only one end of a line is shown on the diagram), it is possible to double-click the diagram and arrows will appear to indicate that the line connects to a terminal that is not shown. Figure 9.6.1 provides an illustration.

Figure 9.6.1: Illustration of single line diagram connectivity

9.6.3

Building Single Line Diagrams from Imported Data

When a power system model is imported from DGS format that includes graphical information or GIS data, single line diagram/s will automatically be created. However, if a model is imported from another program it may only include network data (some data converters provided in PowerFactory do also import graphics files). Even without a single line diagram, it is possible to perform load-flow and other calculations, and new single line diagram can be created by drawing existing database elements. This is done by first creating a new single line graphic object in the Diagrams folder of the Network Model (right-click the Diagrams folder and select New → Graphic). This opens the single line graphic dialogue, where the ’Current Net Data’ pointer should be set to the respective grid folder. See Section 9.7 for more information. As soon as the correct folder has been set, and OK has been pressed, the single line graphic object ( ) is created and a blank graphic page will be displayed. The Draw Existing Net Elements ( ) icon on the graphics toolbar may now be pressed. This opens a database browser listing all elements considered by the active study case (see Figure 9.6.2) and which have not yet been inserted into the new single line graphic. This list may be filtered to show only particular grids or all grids by using the drop down window (Figure 9.6.2, red square) provided. Once a drawing tool is chosen, in this case the Terminal tool, the list is further filtered to show only terminals, as can be seen in the example. When the user now clicks on the graphic the highlighted terminal (in the browser, Figure 9.6.2) will be removed from the list and placed onto the graphic, and the next terminal down will be highlighted, ready for placement. 98

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9.7. GRAPHIC COMMANDS, OPTIONS, AND SETTINGS

Figure 9.6.2: Using the Draw Net Elements tool

After all busbars have been inserted into the single line graphic, branch elements may be selected in the graphic toolbox. When one of the branch elements is selected in the browser, the corresponding two busbars will be highlighted in the single line graphic. This is also why the nodes should first be placed on the graphic. Branch elements are placed once the nodes are in position. See also: 9.6.1: Drawing Existing Terminals 9.6.2: Drawing Existing Lines, Switches, and Transformers Note: Another useful approach to developing single line diagrams is to first define a feeder (say, at the cubicle closest to the source node), then run a load-flow, navigate to the feeder in the data manager, right-click and select Show → Schematic visualization by Distance or Bus Index. See Section 13.5 (Feeders) for further information on how to define feeders.

Note: Before placing elements onto the graphic users may find it useful to configure and display a background layer. This will be an image of an existing single line diagram of the system. It may be used to ’trace’ over so that the PowerFactory network looks the same as current paper depictions; see Section 9.7.4 for more information on layers.

9.7

Graphic Commands, Options, and Settings

In this section the commands, options and settings that are available in PowerFactory to configure and use the graphic windows are introduced. The sub-sections of this chapter are divided as illustrated in Figure 9.7.1.

Figure 9.7.1: Categories of graphic commands, options, and settings

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9.7.1

Zoom, Pan, and Select Commands

Figure 9.7.2 shows the commands available for zooming, panning, and selecting. These commands are also available from the main menu under ’View’. The commands are described below.

Figure 9.7.2: Zoom, Pan, and Select Commands

Freeze Mode: Locks the diagram from graphical changes, no network elements can be added or deleted. Note that the status of switches can still be modified when freeze mode is on. Zoom In: Press the Zoom In icon to change the cursor to a magnifying glass. The mouse can then be clicked and dragged to select a rectangular area to be zoomed. When the frame encompasses the area you wish to zoom into release the mouse button. Alternatively, Ctrl+- and Ctrl++ keys can be used to zoom in and out, or Ctrl and the mouse scroll wheel. Note: The Acceleration Factor for zooming and panning can be changed on the second page of the Graphic Window page in User Settings.

Zoom Back: To zoom “back" press the Zoom Out button - this will step the zoom back to the last state. Zoom All: Zooms to the page extends. Zoom Level: Zooms to a custom or pre-defined level. Hand Tool: Use the hand tool to pan the single line diagram (when not at the page extends). Alternatively, the mouse scroll wheel can be used to scroll vertically, and Ctrl+Arrow keys used to scroll vertically and horizontally. When zoomed to the extent of the page, the tool will automatically switch to either ’Rectangular Selection’ or ’Free-form Selection’. Rectangular Selection: Used to select a rectangular section of the single line diagram. Note that this icon is generally depressed when using the mouse pointer for other tasks, such as selecting Menu items, however the ’Hand Tool’ or ’Free-form Selection’ may also be used. 100

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9.7. GRAPHIC COMMANDS, OPTIONS, AND SETTINGS Free-form Selection: Used to select a custom area of the single line diagram.

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CHAPTER 9. NETWORK GRAPHICS (SINGLE LINE DIAGRAMS) Mark All Elements: This function marks (selects) all objects in the single line diagram. This is helpful for moving the whole drawing to another place or copying the whole drawing into the clipboard. In block diagrams the surrounding block will not be marked. The keyboard short cut Ctrl+A may also be used to perform this action.

9.7.2

Page, Graphic, and Print Options

Figure 9.7.3 shows the page, graphic, and print options buttons available. These commands are discussed in this section, as well as some commands available through the page tab menu.

Figure 9.7.3: Page, Graphic, and Print Options

Print: This function will send the graphic to a printer. A printer dialogue will first appear. Also accessed through: Main Menu: File → Print Keyboard: Ctrl+P Drawing Format: The drawing area for single line diagrams, block diagrams and virtual instruments is modified in the “Drawing Format" dialogue. A predefined paper format can be selected as-is, edited, or a new format be defined. The selected paper format has ’Landscape’ orientation by default and can be rotated by 90 degrees by selecting ’Portrait’. The format definitions, which are shown when an existing format is edited or when a new format is defined, also show the landscape dimensions for the paper format. It is not possible to draw outside the selected drawing area. If a drawing no longer fits to the selected drawing size, then a larger format should be selected. The existing graphs or diagrams are repositioned on the new format (use Ctrl+A to mark all objects and then grab and move the entire graphic by left clicking and holding the mouse key down on one of the marked objects; drag the graphic to a new position if desired). If no ’Subsize for Printing’ format has been selected, then, at printing time, the drawing area will be scaled to fit the paper size of the printer. If, for instance, the drawing area is A3 and the selected paper in the printer is A4, then the graphs/diagrams will be printed at 70% of their original size. By selecting a subsize for printing, the scaling of the drawing at printing time can be controlled. The dimensions of the sub-sized printing pages are shown in the graphic page. If, for instance, the drawing size has been selected as A3 landscape, and the printing size as A4 portrait, then a vertical grey line will divide the drawing area in two halves. The drawing area will be accordingly partitioned at printing time and will be printed across two A4 pages. Make sure that the selected subsize for used for printing is available at the printer. The printed pages are scaled to the available physical paper if this is not the case. For instance: 102

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9.7. GRAPHIC COMMANDS, OPTIONS, AND SETTINGS • The drawing area has been selected as A2 landscape. • The subsize for printing has been selected as A3 portrait. The A2 drawing is thus to be printed across two pages. • Suppose that the selected printer only has A4 paper. The original A2 drawing is then scaled down to 70% and printed on two A4 sheets of paper. Also accessed through: Main Menu: File → Page Setup Rebuild: The drawing may not be updated correctly in some circumstances. The rebuild function updates the currently visible page by updating the drawing from the database. Also accessed through: Main Menu: Edit → Rebuild Right-Click: Drawing → Rebuild Insert New Graphic: Inserts a new graphic object into the Graphic Board folder of the active study case and presents a blank graphics page to the user. A dialogue to configure the new graphics object will appear first. Also accessed through: Page Tab Menu: Insert Page → Create New Page Note: The Page Tab menu is opened by right-clicking a page tab, shown just below the single line diagram.

Insert Existing Graphic: Inserts existing graphics, which may be one of the following: • Graphic folder object (IntGrfnet, lected graphic.

single line network or substation diagrams) → opens the se-

• Terminal (ElmTerm, ) opens the station graphic of the selected terminal (this may also be accessed by right-clicking the terminal in a Data Manager, or a terminal on the single line graphic → Show Station Graphic. • Block Definition (BlkDef, ) → The graphic of the block definition is opened. If there is no graphic defined for the block definitions the command is not executed • Virtual Instrument Panels (SetVipage) → A copy of the selected virtual instrument panel is created and displayed. Graphic folder objects (IntGrfnet) may be opened in more than one Graphics Board at the same time, even more than once in the same Graphics Board. Changes made to a graphic will show themselves on all pages on which the graphic object is displayed. Also accessed through: Page Tab Menu: Insert Page → Open Existing Page Other Page Commands: Other page commands accessed through the Page Tab Menu are as follows: Remove Page: This function will remove the selected graphic from the Graphics Board. The graphic itself will not be deleted and can be re-inserted to the current or any other Graphics Board at any time. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 9. NETWORK GRAPHICS (SINGLE LINE DIAGRAMS) Rename Page: This function can be used to change the name of the selected graphic. Move/Copy Page(s): This function can be used to move a page/s to modify the order of graphics. Also accessed through: Mouse Click: Left-click and select a single page (optionally press control and select multiple pages) and drag the page/s to change the order graphics are displayed. Data Manager: (Advanced) Modify the order field of Graphics Pages listed within the Study Case Graphics Board. To reflect the changes, the study case should be deactivated and then reactivated.

9.7.3

Graphic Options

Each graphic window has its own settings, which may be changed using the Graphic Options function ( ).

9.7.3.1

Basic Attributes page:

This function presents a dialogue for the following settings. See Figure 9.7.4. Name The name of the graphic Current Grid Data The reference to the database folder in which new power system elements created in this graphic will be stored. Write protected If enabled, the single line graphic can not be modified. The drawing toolboxes are not displayed and the ’freeze’ icon becomes inactive. Snap Snaps the mouse onto the drawing raster. Grid Shows the drawing raster using small points. Ortho-Type Defines if and how non-orthogonal lines are permitted: • Ortho Off: Connections will be drawn exactly as their line points were set. • Ortho: Allow only right-angle connections between objects. • Semi Ortho: The first segment of a connection that leads away from a busbar or terminal will always be drawn orthogonally. Line Style for Cables Is used to select a line style for all cables. Line Style for Overhead Lines Is used to select a line style for all overhead lines. Offset Factor for Branch Symbols Defines the length of a connection when a branch symbol is drawn by clicking on the busbar/terminal. This is the default distance from the busbar/terminal in grid points. Allow Individual Line Style Permits the line style to be set for individual lines. The individual style may be set for any line in the graphic by right-clicking the line → Set Individual Line Style. This may also be performed for a group of selected lines/cables in one action, by first multi selecting the elements.

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9.7. GRAPHIC COMMANDS, OPTIONS, AND SETTINGS Allow Individual Line Width As for the individual line style, but may be used in combination with the “Line Style for Cables/Overhead Lines" option. The individual width is defined by selecting the corresponding option in the right mouse menu (may also be performed for a group of selected lines/cables in one action).

Figure 9.7.4: Graphic Options dialogue

Text Boxes page: Boxes of Object Names - Background Specifies the transparency of object names boxes: • Opaque: Means that objects behind the results box cannot be seen through the results box. • Transparent: Means that objects behind the results box can be seen through the results box. Result Boxes - Background Specifies the transparency of result boxes (as boxes of object names). Always show result boxes of detailed couplers Self-explanatory. Space saving representation of result boxes on connection lines Self-explanatory. Show line from General Textboxes to referenced objects may be disabled to unclutter the graphic. Reset textboxes completely Textboxes and result boxes have reference points (the point on the box at which the box will ’attach’ to its element) that may be changed by the user. If this option is: • Enabled: The default reference will be used. • Disabled: The user defined reference will be used.

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Switches page:

Cubicle representation Selects the switch representation (see Figure 9.7.5): • Permanent Box: Shows a solid black square for a closed and an frame line for an open switch (left picture). • Old Style Switch: Shows the switches as the more conventional switch symbol (right picture).

Figure 9.7.5: Cubicle representations

Display Frame around Switches Draws a frame around the switch itself (Breakers, Disconnectors, etc.). This only applies to user-drawn breakers and disconnectors. Create switches when connecting to terminal Self-explanatory. Show connected busbars as small dots in simplified substation representation Defines how the connection points on busbars are represented in busbar systems. Additional Attributes and Coordinates pages should generally only be configured with the assistance of DIgSILENT support staff. Note that if Use Scaling Factor for Computation of Distances is selected on the Coordinates page, it is possible to calculate the length of lines on the Single Line Graphic by right-clicking and selecting Measure Length of Lines. Also accessed through: Right-click: Graphic Options Note: The settings for the cursor type for the graphic windows (arrow or tracking cross) may be set in the User Settings dialogue, see Section 7.2 Graphic Windows Settings. This is because the cursor shape is a global setting, valid for all graphic windows, while all graphic settings described above are specific for each graphic window.

9.7.4

Layers

The single line graphic and the Block diagram graphic windows use transparent layers of drawing sheets on which the graphical symbols are placed. Each of these layers may be set to be visible or not. The names of objects that have been drawn, for example, are on a layer called ’Object Names’ and may be made visible or invisible to the user. Which layers are visible and exactly what is shown on a layer is defined in the ’Graphical Layers’ dialogue, accessed through the main toolbar ( ), by right-clicking on an empty spot of the graphic area 106

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9.7. GRAPHIC COMMANDS, OPTIONS, AND SETTINGS → Show Layer, or selecting View → Layers from the main menu. The layers dialogue has a “Visibility" page to determine which layers will be visible, and a “Configuration" page to define various attributes for the layers. See Figure 9.7.6. In Figure 9.7.6, the layers in the left pane (Base Level, Object Names, Results, etc.) are visible in the graphical window. The layers in the right pane are invisible. Layers can be made visible by multi selectbutton (alternatively, double-click ing them (hold the Ctrl key down whilst selecting) and pressing the a layer name and it will jump to the other pane). A layer can be made invisible again by selecting it in the left pane and pressing the button or by double-clicking it. It is also possible to define user-specific layers, by pressing the New button.

Figure 9.7.6: Graphical layers dialogue (SetLevelvis)

The layers existing in PowerFactory are described in Table 9.7.1. Each graphic symbol in a single line diagram or block diagram is assigned to default layer at first. All busbar symbols, for example, are drawn on the ’Base Level’ layer by default. Graphic symbols may be shifted onto other layers by right-clicking them in the single line graphic and selecting the option Shift to Layer from the context sensitive menu. This option will show a second menu with all layers. Selecting a layer will move all selected symbols to that layer. Moving symbols from one layer to another is normally only needed when only a few symbols from a certain group should be made visible (for instance the result boxes of one or two specific junction node), or when user defined layers are used. Note: Certain names and results boxes are, by default, assigned to the ’Invisible Objects’ layer. An example are the names and results boxes for point terminals. This is done to unclutter the graphic. Should the user wish to display names and/or results boxes for certain Junction / Internal nodes simply make the ’Invisible Objects’ layer visible and re-assign the names and results boxes required to another layer, such as the ’Object Names’ or ’Results’ layers - then make the ’Invisible Objects’ layer invisible once more.

The ’Configuration’ page has a drop down list showing all layers that may be configured by the user. Considering the ’Object Names’ layer as shown in Figure 9.7.7, it may be seen that a target (or focus) may be set. The selected target will be the focus of the performed configuration command. Various actions or settings may be performed, such as e.g. changing the font using the Change Font button. The configuration page may also be used to mark (select/ highlight) the target objects in the graphic using the Mark button. The options available to configure a layer depend on the type of Layer. Table 9.7.1 shows for each layer in which way its content can be changed in format. DIgSILENT PowerFactory 15, User Manual

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Figure 9.7.7: Graphical layers configuration page

As and example, suppose that a part of the single line graphics is to be changed, for instance, to allow for longer busbar names. To change the settings, the correct graphical layer is first selected. In this example, it will be the ’Object Names’ layer. In this layer, only the busbar names are to be changed, and the target must therefore be set to ’All Nodes’. When the layer and the target has been selected, the width for object names may be set in the Settings area. The number of columns may be set using the Visibility/Frame/Width button. Alternatively, the Adapt Width will adapt all of the object name placeholders to the length of the name for each object. Changing a setting for all nodes or all branches at once will overwrite the present settings. Note: Should an object disappear when it has been re-assigned to a layer, that layer may be invisible. Layer visibility should be inspected and changed if required.

Layer

Base Level Object Names Results

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Content Symbols for the elements of the grid Boxes with names and additional data description, if configured Boxes with calculation results

Diagram Type Configuration SL Single Line Options B Block Text/Box Format

SL/B

Text/Box Format

SL/B

Text/Box Format

SL/B

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Layer

Connection Points

Device Data Invisible Objects

Background

Numbers of connection lines Sections and Line Loads Connection Arrows Tap Positions Vector Groups

Direction Arrows

Phases Connection Numbers Connection Names Signals Block Definition

Content Dots at the connections between edges and buses/terminals and signal connections to blocks Additional Text explanation given in the device symbol Layer containing the symbols of elements hidden by default Graphic used as the background (Swallpa¸ ˇ perT) to allow easier drawing of the diagram or to show additional information (map information) Number of lines for each connection Symbols at lines consisting of sections and/or where line loads are connected Double-Arrow at connections where the end point is not represented in the current diagram. Positions of taps for shunts and transformers Vector group for rotating machines and transformers Arrows that can be configured for active and reactive power flow representation Number of phases of a line/cable, shown as parallel lines Index of each possible block connection point Name of each unused connection of a block Name of the signal transmitted Definition each block is based on

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Diagram Type Configuration SL Single Line Options B Block Text/Box Format

SL/B

Text/Box Format

SL/B

Text/Box Format

SL/B

Name of file with graphics (WMF, DXF, BMP, JPEG, PNG, GIF, TIF)

SL/B

Text/Box Format

SL

Text/Box Format

SL

Text/Box Format

SL

Text/Box Format

SL

Text/Box Format

SL

Active/Reactive Power for direct/ inverse/ SL homopolar system Text/Box Format Text/Box mat Text/Box mat Text/Box mat Text/Box mat

ForForForFor-

SL B B B B

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Layer

Content

Diagram Type Configuration SL Single Line Options B Block

Remote Controlled Substations

Remote Controlled Substations

Colour

Annotations

9.7.5

SL

Text/Box ForSL mat Table 9.7.1: Diagram Layers of PowerFactory Annotations in the graphic

Element Options

Figure 9.7.8 shows the commands available for zooming, panning, and selecting.

Figure 9.7.8: Element options

Edit and Browse Data: This option lets the user edit the device data of all marked objects in the drawing. If only one object is marked, then this object’s edit dialogue will be displayed. When more than one object is marked, the Data Manager window will show the list of marked objects. As with a normal Data Manager, these objects can be double-clicked to open their edit dialogues. See Chapter 10 (Data Manager) for more information. Note: Changes made in the device data of objects are not registered by the graphical Undo Function. Undoing these changes is therefore not possible.

Also accessed through: Right-click: Edit and Browse Data Note: To edit data for a single element, double-click the element, or select the element and press Alt+Return.

Delete Element: This function deletes all marked objects in the diagram. The database objects for the graphical object will also be deleted (a warning message will pop up first - this may be switched off in the “User Settings" dialogue; see Section 7.2 (Graphic Windows Settings). 110

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9.7. GRAPHIC COMMANDS, OPTIONS, AND SETTINGS Also accessed through: Right-click: Delete Keyboard: Del Note: To delete graphical objects only, right click the selected element/s and select ’Delete Graphical Object only’.

Cut: This function cuts the marked objects in the diagram. Objects can then later be pasted as discussed below. Also accessed through: Right-click: Cut Keyboard: CTRL+X Copy: Copies all marked objects from the current drawing and puts them into the clipboard. Also accessed through: Right-click: Delete Keyboard: CTRL+C Paste: Copies all objects from the clipboard and pastes them into the current drawing. The objects are pasted at the current graphical mouse position. Objects that are copied and pasted create completely new graphic and data objects in the graphic that they are pasted into. Also accessed through: Right-click: Paste Keyboard: CTRL+V Note: If you wish to copy and paste just the graphic, then choose Paste Graphic Only from the rightclick menu. Similar results are obtained when using the “Draw Existing Net Elements" tool (see Section 9.6: Drawing Diagrams with Existing Network Elements).

Note: The undo command undoes the last graphic action and restore deleted elements, or deletes created elements. Note that data that has been deleted or changed will not be restored. The undo command is accessed through the undo icon ( ), by right-clicking and selecting ’Undo’, or by pressing Ctrl+Z.

Reconnect Element: Disconnects the selected elements and then presents the element for immediate re-connection. The branch to be connected will be ’glued’ to the cursor. Left clicking a bar or terminal will connect the element. Also accessed through: Right-click: Reconnect Element Note: Elements can also be disconnected and connected by selecting right-clicking and selecting ’Disconnect’ or ’Connect’.

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CHAPTER 9. NETWORK GRAPHICS (SINGLE LINE DIAGRAMS) Other Commands: Rotate: Right-click selection and ’Rotate’ to rotate symbols clockwise, counter-clockwise, or 180 degrees. It is generally preferable to disconnect an element before rotating it. Disconnect: Right-click and select ’Disconnect’ to disconnect the selected element/s. Connect: Right-click and select ’Connect’ to connect an element. Redraw: Right-click and select ’Redraw’ to redraw a selected element. Move: Marked objects can be moved by left clicking them and holding down the mouse button. The objects can be moved when the cursor changes to an arrowed cross ( ). Hold down the mouse button and drag the marked objects to their new position. Connections from the moved part of the drawing to other objects will be adjusted. Edit Line Points: Right-click and select ’Edit Line Points’ will show the black squares (’line points’) that define the shape of the connection. Each of these squares can be moved by left clicking and dragging them to a new position (see Figure 9.7.9). New squares can be inserted by left clicking the connection in between squares. Line points are deleted by right-clicking them and selecting the Delete Vertex option from the case sensitive menu. This menu also presents the option to stop (end) the line point editing, which can also be done by left clicking somewhere outside the selected lines.

Figure 9.7.9: Editing line points

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9.7. GRAPHIC COMMANDS, OPTIONS, AND SETTINGS

9.7.6

Graphic Attributes and Options

Figure 9.7.10 shows the commands available for zooming, panning, and selecting.

Figure 9.7.10: Graphic Attributes and Options

9.7.6.1

Select Graphic Attributes:

This dialogue sets the line style, line width, brush style, colour and font, for annotations (i.e. not for power system elements). The line style includes several kinds of dashed or dotted lines and one special line style: the TRUE DOTS style. This style will only put a dot at the actual coordinates. In a single line graphic, this means only at the start and the end, which does not make much sense. For result graphs, however, the TRUE DOTS style will only show the actual data points. The brush style is used to fill solid symbols like squares and circles. These settings may also be accessed by simply double-clicking an annotation.

9.7.6.2

Diagram Colouring:

The single line graphic window has an automatic colour representation mode. The Diagram Colouring icon on the local toolbar will open the diagram colouring representation dialogue (alternatively, select View → Diagram Colouring on the main menu). This dialogue is used to select different colouring modes and is dependent if a calculation has been performed or not. If a specific calculation is valid, then the selected colouring for that calculation is displayed. The Diagram Colouring has a 3-priority level colouring scheme also implemented, allowing colouring elements according to the following criteria: 1𝑠𝑡 Energizing status, 2𝑛𝑑 Alarm and 3𝑟𝑑 “Normal" (Other) colouring. Energizing Status If this check box is enabled “De-energized" or “Out of Calculation" elements are coloured according to the settings in the “Project Colour Settings". The settings of the “Deenergized" or “Out of Calculation" mode can be edited by clicking on the Colour Settings button. Alarm If this check box is enabled a drop down list containing alarm modes will be available. It is important to note here that only alarm modes available for the current calculation page will be listed. If an alarm mode is selected, elements “exceeding" the corresponding a limit are coloured. Limits and colours can be defined by clicking on the Colour Settings button. “Normal" (Other) Colouring Here, two lists are displayed. The first list will contains all available colouring modes. The second list will contain all sub modes of the selected colouring mode. The settings of the different colouring modes can be edited by clicking on the Colour Settings button. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 9. NETWORK GRAPHICS (SINGLE LINE DIAGRAMS) Every element can be coloured by one of the three previous criteria. Also, every criterion is optional and will be skipped if disabled. Regarding the priority, if the user enables all three criterion, the hierarchy taken account will be the following: • “Energizing Status" overrules the “Alarm" and “Normal Colouring" mode. The “Alarm" mode overrules the “Normal Colouring" mode. The graphic can be coloured according to the following listed below. Availability of some options will depend on the Function that is selected (e.g. ’Voltage Violations’ does not appear when the ’Basic Data’ page is selected, but does when the ’Load Flow’ page is selected). Energizing Status: • De-energized • Out of Calculation Alarm: • Feeder Radiality Check (Only if “Feeder is supposed to be operated radially" is selected). • Outages • Overloading of Thermal/Peak Short Circuit Current • Voltage Violations/Overloadings “Normal" (Other) Colouring: • Results – Average Interruption Duration – Fault Clearing Times – Load Point Energy Not Supplied – Loading of Thermal / Peak Short-Circuit Current – State Estimator – Voltages / Loading – Yearly interruption frequency – Yearly interruption time – Incident Energy – PPE - Category • Topology – Boundaries (Definition) – Boundaries (Interior Region) – Connected Components – Connected Components, Voltage Level – Connected Grid Components – Energizing Status – Feeders – Missing graphical connections – Outage Check 114

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9.7. GRAPHIC COMMANDS, OPTIONS, AND SETTINGS – Station Connectivity – Station Connectivity (Beach Balls only) – Supplied by Secondary Substation – Supplied by Substation – System Type AC/DC and Phases – Voltage Levels • Primary Equipment – Cross Section – Forced Outage Duration – Forced Outage Rate – Year of Construction • Secondary Equipment – Measurement Locations – Power Restoration – Relays, Current and Voltage Transformers – Switches, Type & Usage • Groupings (Grids, Zones, Areas...) – Areas – Grids – Meteo Stations – Operators – Owners – Paths – Routes – Zones • Variations / System Stages – Modifications in Recording Expansion Stage – Modifications in Variations / System Stages – Original Locations • User-defined – Individual An illustration of diagram colouring options is shown in Figure 9.7.11. In this case, the Voltage Colouring Mode is set to ’Voltage Drop and Rise’, under ’Colour Settings’. Also, the ’Colouring scheme for voltages and loading’ is set to ’Continuous’ on the Advanced tab.

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Figure 9.7.11: Illustration of diagram colouring

9.7.6.3

Show Title Block:

The title block can be turned on and off from the single line diagram toolbar ( ) or the ’View’ menu. The title block is placed in the lower right corner of the drawing area by default, see Figure 9.7.12 for an example.

Figure 9.7.12: Single line title mask

The contents and size of the title mask can be changed by right-clicking the title block and selecting the Edit Data option from the context sensitive menu. The Select Title dialogue that pops up is used to scale the size of the title block by setting the size of the block in percent of the default size. The font used will be scaled accordingly. To edit the text in the title block press the edit button ( ) for the ’Title Text’ field. All text fields have a fixed format in the title block. The data and time fields may be chosen as automatic or user defined. Most text fields are limited to a certain number of characters. When opening a new graphic the title will appear by default.

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9.8. EDITING AND CHANGING SYMBOLS OF ELEMENTS 9.7.6.4

Show Legend Block:

The legend block can be turned on and off from the single line diagram toolbar ( ), or from the ’View’ menu. The legend block describes the contents of result boxes (for information about result boxes see 9.9). Because more than one type of result box is normally used in the Single line graphic, for instance, one for node results and another one for branch results, the legend box normally shows more than one column of legends. After changing the result box definitions, it may be required to manually resize the legend box in order to show all result box legends. The Legend Box definition dialogue is opened by right-clicking the legend block and selecting Edit Data from the context sensitive menu. The font and format shown may be configured. When opening a new graphic the legend will appear by default.

9.7.6.5

Colour Legend Block:

The colour legend block can be turned on and off from the single line diagram toolbar ( ), or from the ’View’ menu. The legend updates automatically based on the colouring options selected.

9.7.7

Node Default Options

Figure 9.7.13 shows the commands available for setting node default options. These are discussed in further detail in this section.

Figure 9.7.13: Node default options

Default Voltage Levels for Terminals and Busbars: The default voltage level for terminals can be set in this field. New terminals placed on the single line diagram will have this voltage (e.g. 110 kV, 0.4 kV). Default Phase Technologies for Terminals: The default phase technology for terminals can be set in this field. New terminals placed on the single line diagram will be of this type (e.g. three-phase ABC, one-phase, DC, etc.).

9.8

Editing and Changing Symbols of Elements

You can edit or change the symbols, which are used to represent the elements in the single line graphic. Click with the right mouse button on a symbol of an element in the single line graphic, then either: • Select Edit Graphic Object from the context sensitive menu in order to edit the symbol of the element. Note that colour changes will only be displayed if Other → User-defined is selected in the Diagram Colouring options.

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CHAPTER 9. NETWORK GRAPHICS (SINGLE LINE DIAGRAMS) • Select Change Symbol from the context sensitive menu in order to use a different symbol for the element. PowerFactory supports user-defined symbols as Windows-Metafile (* .wmf) and Bitmap (* .bmp) files. For additional information refer to Appendix F (Element Symbol Definition).

9.9

Results Boxes, Text Boxes and Labels

PowerFactory uses results boxes, text boxes, and labels in the Single Line Diagram to display calculation results and other useful information. Figure 9.9.1 illustrates how these can be shown in the Single Line Diagram.

Figure 9.9.1: Results boxes, text boxes, and labels available in PowerFactory

9.9.1

Results Boxes

General: Result boxes are generally set up so that there are a series of different formats for each calculation function, with variables appropriate to that function. In addition, the format differs for the objects class and/or for individual objects. For example, following a load-flow, branch and edge elements will have different formats compared to nodes, and an external grid will have an individual, different, format as compared to the branch and edge elements. The result box itself is actually a small output report, based on a form definition. This form definition, and the PowerFactory output language that is used to define it, allows for the display of a wide range of calculated values, object parameters, and even for colouring or user defined text. Although the result boxes in the single line graphic are a very versatile and powerful way for displaying calculation results, it is often not possible to display a large (part of a) power system without making the result boxes too small to be read. PowerFactory solves this problem by offering balloon help on the result boxes. Positioning the mouse over a result box will pop up a yellow text balloon with the text displayed in a fixed size font. This is depicted in Figure 9.9.1. The result box balloon always states the name of the variable, and may thus also be used as a legend.

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9.9. RESULTS BOXES, TEXT BOXES AND LABELS Reference points: A result box is connected to the graphical object for which it displays the results by a ’reference point’. Figure 9.9.1 shows the default reference points for the resultbox of a terminal. A reference point is a connection between a point on the result box (which has 9 optional points), and one of the ’docking’ points of the graphical object. The terminal has three docking points: on the left, in the middle and on the right. The reference point can be changed by: • Right-clicking the resultbox with the graphics cursor (freeze mode off), and selecting Change Reference Points. • The reference points are shown: docking points in green, reference points in red. Select one of the reference points by left-clicking it. • Left-click the selected reference point, and drag it to a red docking point and drop it. • An error message will result if you drop a reference point somewhere else than on a docking point. Result boxes can be freely moved around the diagram. They will remain attached to the docking point, and will move along with the docking point. A result box can be positioned back to its docking point by right-clicking it and selecting Reset Settings from the menu. If the option “Reset textboxes completely" is set in the graphical settings, then the default reference and docking points will be selected again, and the result box is moved back to the default position accordingly. Editing Results Boxes: PowerFactory uses separate result boxes for different groups of power system objects, such as node objects (i.e. busbars, terminals) or edge objects (i.e. lines, loads). For each type of result box, a different result box definition is used. A newly installed version of PowerFactory has pre-defined result box formats for all object groups. These default formats cannot be changed, however the user may define other formats and save these for use. For the edge objects, for example, the default box shows P and Q without units. A number of these predefined formats are available for display; they may be selected by right-clicking a results box to get the Format for Edge Elements (in this example) option, which then presents a number of formats that may be selected. The active format is ticked ( ) and applies for all the visualized edge elements. It is also possible to select predefined formats for an specific element class. If the edge element is for example an asynchronous machine, in the context sensitive menu it will be also possible to get the option Format for Asynchronous Machine, which shows the predefined formats for the element class Asynchronous Machine (ElmAsm). The selected format will in this case apply only to the visualized asynchronous machines. If the user wants to create a specific format that is different from the pre-defined ones, the Edit Format for Edge Elements (or Node Elements) option should be used. Note that the new format will be applied to the entire group of objects (edge or node objects). If a created format is expected to be used for just one specific element, then the Create Textbox option should be used. An additional results box/ textbox will be created, using the current format for the object. This may then be edited. Information about text boxes is given in 9.9.2. When the Edit Format option has been selected the user can modify the variables and how are they showed as described Chapter 17: Reporting and Visualizing Results, Section 17.2.1: Editing Result Boxes.

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CHAPTER 9. NETWORK GRAPHICS (SINGLE LINE DIAGRAMS) Formatting Results Boxes: Result boxes can be formatted by means of the context sensitive menu (right-clicking the desired result box). The available options include: • Shift to layer (see 9.7.4). • Rotate the result box. • Hide the results box. • Change the font type and size of the text. • Change the width. • Set the text alignment. • Adapt width • Change reference points. • Set the default format (Reset Settings, only available after changes have been made). Resetting Calculation Results: When pressed, the Reset Calculation icon ( ) will clear the results shown on the Single Line Diagram. By default, PowerFactory will also clear the calculation results when there is a change to network data or network configuration (such as opening a switch). However, if ’Retention of results after network change’ is set to ’Show last results’ in the User Settings (see Section 7.1: General Settings), results will appear in grey on the Single Line Diagram and on the Flexible Data tab until the calculation is reset, or a new calculation performed. ’Reset Calculation’ can also be accessed from the main menu under ’Calculation’.

9.9.2

Text Boxes

As mentioned before, text boxes are used to display user defined variables from a specific referenced object within the single line graphic. To create a text box, right-click on the desired object (one end of the object when it is a branch element) and select Create Textbox. By default a text box with the same format of the corresponding result box will be generated. The created text box can be edited, to display the desired variables, following the same procedure described in 9.9.1. In this case after right-clicking the text box, the option Edit Format should be selected. By default the text boxes are graphically connected to the referred object by means of a line. This ”connection line” can be made invisible if the option ’show line from General Textboxes....’ from the ’Result Boxes’ page of the Graphic Option dialogue (9.7.3, Figure 9.7.4) is disabled.

9.9.3

Labels

In the general case, a label showing the name of an element within the single line graphic is automatically created with the graphical objects (see Figure 9.9.1). The label can be visualized as a text box showing only the variable corresponding to the name of the object. As for text boxes, the format of labels can be set using the context sensitive menu.

9.9.4

Free Text Labels

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9.10. ANNOTATION LAYER

9.10

Annotation Layer

The Annotation Layer function offers the user the opportunity to include additional graphical information in one or more configurable layers in the single line diagram. Examples include: • Built in graphical annotation elements • text • icons (bitmap files) To draw the Elements in the single line diagram the user has to activate the Freeze Annotation Layer button in the upper right corner (marked in figure 9.10.1).

Figure 9.10.1: Geographical diagram example

The activation of the annotation layer deactivates the selection of power system elements and activates the selection of annotation elements. By selecting an annotation element, the user can place it in the single line diagram. In Addition, the user can choose a *.bmp file as a background image. The annotation elements are as follows: • graphical annotation – Line: – Polyline: – Arrow: – Polyline with arrow: – Polygon: – Rectangle: – Circle: – Pie: – Arc: DIgSILENT PowerFactory 15, User Manual

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CHAPTER 9. NETWORK GRAPHICS (SINGLE LINE DIAGRAMS) • text: • icons (bitmap files): It is possible to create multiple annotation layers. To do this, the user should click on the button and then select the Annotation Layer tab from the Visibility page (see figure 9.10.2). Alternatively, this dialogue can be accessed by right clicking on the single line diagram and select Layers.... A new layer can be created by pressing the edit layers button as illustrated in figure 9.10.2 and the by pressing the icon ( ). The new layer should be given an appropriate name.

Figure 9.10.2: Layer overview

or in the dialogue shown The newly created layers can be made visible or invisible by clicking in figure 9.10.2. The Network Elements layer can not be hidden, since it contains the fundamental Elements of the diagram which are to be annotated. To edit a particular layer the layer has to be selected in the drop-down menu shown in the Layer Edit Modes section of the dialogue. Drawing sequence of Layers If annotation layers are drawn on top of each other the sequence in which the layers are drawn becomes important. The sequence of the layers can be changed by dragging them to a higher or lower position in the Visibility/Order list shown in figure 9.10.2. The first entry in the list will be displayed as the upper layer of the diagram. Layers can be given a higher entry in the list than the Network Elements layer and this will be reflected in the graphic. Export graphical layer 122

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9.11. ANNOTATION OF PROTECTION DEVICE To export a graphical layer the user should press the Edit Layers Button as shown in figure 9.10.2. In the following Window a list of all the available layers is shown. The user can export the layer as an *.svg file as shown in figure 9.10.3. Import graphical layer To import a graphical layer, the user should select the Edit Layers button. By creating a new layer with ( ), it is possible to Import an existing layer as shown in (figure 9.10.4).

Figure 9.10.3: Layer overview

Figure 9.10.4: New Layer

9.11

Annotation of protection device

The functionality of adding a protection device into the single line diagram is shown in section 39.2.2.

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9.12

Geographical Diagrams

In PowerFactory it is possible to specify terminal GPS coordinates, and automatically generate Geographical Diagrams. GPS coordinates (latitude and longitude) are entered on the ’Description’ page of terminals and lines. This is on the Geographical Coordinates tab. Once GPS coordinates are entered, a single geographical diagram can be created by either: • Opening the Data Manager, right-clicking the active project or active grid and selecting ’Show Geographical Diagram’. • On the main menu, on the ’Window’ tab, selecting ’Show Geographical Diagram’. The geographical diagram provides a visual representation of the network, it is not possible to add new elements to the diagram. An additional layer call Load / Generation Distribution is available for GPS coordinates to illustrate the magnitude of network load and generation (apparent power), as illustrated in Figure 9.12.1. Note that the displayed size of circles does not change as the user zooms in and out of the diagram. Colour and ’Scaling Factor’ settings can be modified on the ’Configuration’ page of ’Graphic Layers’, see 9.7.4 (Layers).

Figure 9.12.1: Geographical diagram example

To display background images (e.g. maps) on the geographical diagram a ’File for reading Background Images’ must be selected in the “Geographic Diagram" page of the Graphic Options dialogue. This facilitates ’tiling’ of multiple images in the background of the GPS graphic if required. The ’File for reading background images’ is simply a text file with semi-coma delimited entries in the following format: Image_filename; X1; Y1; X2; Y2 124

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9.12. GEOGRAPHICAL DIAGRAMS Where: • Image_filename is the name of the image file. If it is not in the same directory as the ’File for reading background images’ it should include the file path. • X is the latitude and Y is the longitude. • (X1,Y1) are the bottom-left coordinates of the image. • (X2,Y2) are the top-right coordinates of the image. • The # symbol can be used to comment out entries.

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Chapter 10

Data Manager 10.1

Introduction

To manage/ browse the data in PowerFactory , a Data Manager is provided. The objective of this chapter is to provide detailed information on how this Data Management tool. Before starting, users should ensure that they are familiar with Chapter 4 (PowerFactory Overview).

10.2

Using the Data Manager

The Data Manager provides the user with all the features required to manage and maintain all the data from the projects. It gives both an overview over the complete data base as well as detailed information about the parameters of single power system elements or other objects. New case studies can be defined, new elements can be added, system stages can be created, activated or deleted, parameters can be changed, copied, etc. All of these actions can be instituted and controlled from a single data base window. The data manager uses a tree representation of the whole database, in combination with a versatile data browser.To initially open a data manager window press the icon from the main toolbar. The settings of this window can be edited using the ’User Settings’ dialogue (Section 10.2.5: Data Manager Settings). The data manager window has the following parts (see Figure 10.2.1): • The title bar, which shows the name and path of the of the folder currently selected in the database [1]. • The data manager local tool bar [2]. • In the left upper area the database window, which shows a symbolic tree representation of the complete database [3]. • In the left lower area the input window. It may be used by more experienced users to enter commands directly, instead of using the interactive command buttons/dialogues. By default it is not shown. For further information see Section 10.7 (The Input Window in the Data Manager) [4].The input window is opened and closed by the clicking on the Input Window button ( ). • On the right side is the database browser that shows the contents of the currently selected folder [5]. • Below the database browser and the input window is the message bar, which shows the current status and settings of the database manager (for further information see Section 10.2.5). DIgSILENT PowerFactory 15, User Manual

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CHAPTER 10. DATA MANAGER There are some special features of the database browser which can be accessed at any time when the content of a folder is shown: • Balloon text: this is not only available for the buttons in the tool bar and the active parts of the message bar or the browser window, but also for the data fields [a]. • Active Title buttons of each column; click on any title button to sort the items in the column; first click- items are sorted in ascending order; second click - items are sorted in descending order [b]. • Object buttons showing the object standard icon in the first column of the database browser: each object is represented by a button (here a line object is shown). One click selects the object and a double-click presents the edit dialogue for the object [c].

Figure 10.2.1: The data manager window

PowerFactory makes extensive use of the right mouse button. Each object or folder may be ’right-clicked’ to pop up a context sensitive menu. For the same object the menu presented will differ depending on whether the object is selected in the left or right hand side of the data manager (this is known as a ’context sensitive’ menu). Generally, the left hand side of the data manager will show object folders only. That is, objects that contain other objects inside them. The right hand side of the data manager shows object folders as well as individual objects.

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10.2. USING THE DATA MANAGER

Figure 10.2.2: Context sensitive menus in the data manager

Using the right mouse button to access menus is usually the most effective means of accessing features or commands. Figure 10.2.2 shows an Illustration of a context-sensitive right mouse button menu. The symbolic tree representation of the complete database shown in the database window may not show all parts of the database. The user settings offer options for displaying hidden folders, or for displaying parts that represent complete stations. Set these options as required (Section 10.2.5: Data Manager Settings). Note: It is useful to keep in mind that object folders, such as the grid ( ) folder are merely common folders , that have been designated to contain particular classes of objects.

10.2.1

Navigating the Database Tree

There are several ways to ”walk” up and down the database tree: • Use the mouse: all folders that have a “+" sign next to them may be expanded by double-clicking on the folder, or by single clicking the “+" sign. • Use the keyboard: the arrow keys are used to walk up and down the tree and to open or close folders (left and right arrows). The Page Up and Page Down keys jump up and down the tree in big steps and the “-" and “+" keys may also be used to open or close folders. • Use the toolbar in combination with the browser window. Double-click objects (see “c" in Figure 10.2.1) in the browser to open the corresponding object. This could result in opening a folder, in the case of a common or case folder, or editing the object dialogue for an object. Once again, the action resulting from your input depends on where the input has occurred (left or right side of the data manager). DIgSILENT PowerFactory 15, User Manual

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CHAPTER 10. DATA MANAGER • The buttons Up Level ( ) and Down Level ( move up and down the database tree.

10.2.2

) on the data manager tool bar can be used to

Adding New Items

Generally, new network components are added to the database via the graphical user interface (see Section 9.2: Defining Network Models with the Graphical Editor), such as when a line is drawn between two nodes creating, not only the graphical object on the graphics board, but also the corresponding element data in the relevant grid folder. However, users may also create new objects “manually" in the database, from the data manager. Certain new folders and objects may be created by right-clicking on folders in the data manager. A context sensitive menu is presented, offering a choice of objects to be created that will “fit" the selected folder. For example, right-clicking a grid folder will allow the creation (under the New menu) of a Graphic, a Branch, a Substation, a Site or a Folder object. The new object will be created in the folder that was selected prior to the new object button being pressed. This folder is said to have the ’focus’ for the commanded action. This means that some objects may not be possible to create since the focused folder may not be suited to hold that object. For instance: A synchronous machine should not go into a line folder. A line folder should contain only line routes, line sections and cubicles. The cubicles in their turn should contain only switches or protection elements. icon must be pressed (new object To access the whole range of objects that may be created, the icon). This is found the data manager toolbar and presents the dialogue shown in Figure 10.2.3. To simplify the selection of the new objects, a filter is used to sort the object list. This filter determines what sort of list will appear in the drop-down list of the ’Element’ field. If “Branch Net Elements" is first selected, the selection of, for instance, a 2-winding transformer is accomplished by then scrolling down the element list. The Element field is a normal edit field. It is therefore possible to type the identity name of the new element, like ElmTr3 for a three-winding transformer, or TypLne for a line type directly into the field. The possible list of new objects is therefore context sensitive and depends on the type or class of the originally selected folder.

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Figure 10.2.3: The element selection dialogue

After the selection for a new object has been confirmed, the “Element Selection" dialogue will close, the new object will be inserted into the database and the edit dialogue for the new object will pop up. If this dialogue is closed by pressing the Cancel button, the whole action of inserting the new object will be cancelled: the newly created object will be deleted from the active folder. The dialogue for the new object may now be edited and the OK button pressed to save the object to the database. As any other object, folders can be created either by using the context sensitive menu or by using the icon. Common folders (IntFolder objects) may have an owner name entered, for documentation or organizational purposes. In this way it should be clear who has created the data. Descriptions may also be added. An existing folder may be edited by using the Edit icon on the toolbar or by using the right mouse button. Each folder may be set to be read-only, or to be a PowerFactory system folder. The folder may be a “Common" or “Library" folder. These attributes can be changed in the edit-folder dialogue. These settings have the following meaning: • Common folders are used for storing non-type objects: electric elements, command objects, settings, projects, etc. • Type folders are used as ’libraries’ for type objects. • System folders, which are read only folders The use of read-only folders is clear: they protect the data. In addition, folders containing data that is not normally accessed may be hidden. Selecting the kind of folders that the user/administrator wants to be hidden is done in the user settings dialogue see Chapter 7 (User Settings).

10.2.3

Deleting an Item

A folder or object which is selected may be deleted by pressing the Delete key on the keyboard, or by clicking the icon on the toolbar of the database manager. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 10. DATA MANAGER Because most power system objects that are stored in the database are interconnected through a network topology or through type-element relationships, deleting objects often causes anomalies in the database consistency. Of course, PowerFactory knows at any moment which objects are used by which others and could prevent the user from creating an inconsistency by refusing to delete an object that is used by others. This, however, would create a very stubborn program. PowerFactory solves this problem by using a ’Recycle Bin’ folder. All deleted objects are in fact moved to the recycle bin. All references to the deleted objects will therefore stay valid (for example, the reference between element and type), but will show that the referenced object has been “deleted" by: • Showing the path to the recycle bin and the name of the ”recycle object” in stead of the original location and name. • Colouring: a reference to a deleted object will be coloured red, i.e. a reference to a type. Type references are found in the edit dialogues of all elements which use a type like the line or the transformer object. An object that has been deleted by mistake can be restored to the original location by selecting the restore menu option on the recycle object’s context sensitive menu. All references to the object will also be restored.

10.2.4

Cut, Copy, Paste and Move Objects

Cut, Copy and Paste Cutting, copying and pasting may be achieved in four different manners: 1. By using the data manager tool bar buttons. 2. By using the normal ’MS Windows’ shortcuts: • Ctrl-X will cut a selection, • Ctrl-C will copy it, • Ctrl-V will paste the selection to the active folder. Cutting a selection will colour the item-icons gray. The cut objects will remain in their current folder until they are pasted. A cut-and-paste is exactly the same as moving the object, using the context sensitive menu. All references to objects that are being moved will be updated. Cancelling a cut-and-paste operation is performed by pressing the Ctrl-C key after the Ctrl-X key has been pressed. 3. By using the context sensitive menu. This menu offers a Cut, a Copy and a Move item. The move item will pop up a small second database tree in which the target folder can be selected. When the selected objects have been Cut or Copied, the context sensitive menu will then show a Paste, Paste Shortcut and a Paste Data item. • Paste will paste the selection to the focused folder. • Paste Shortcut will not paste the copied objects, but will create shortcuts to these objects. A shortcut object acts like a normal object. Changes made to the shortcut object will change the original object. All other shortcuts to this original object will reflect these changes immediately • Paste Data is only be available when just one object is copied, and when the selected target object is the same kind of object as the copied one. In that case, Paste Data will paste all data from the copied object into the target object. This will make the two objects identical, except for the name and the connections.

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10.2. USING THE DATA MANAGER 4. By dragging selected objects to another folder. The ’Drag & Drop’ option must be enabled first by double-clicking the ’Drag & Drop: off’ message on the data manager’s message bar. When the Drag & Drop option is on, it is possible to copy or move single objects by selecting them and dragging them to another folder. Dragging is done by holding down the left mouse button after an object has been selected and keeping it down while moving the cursor to the target/destination folder, either in the database tree or in the database browser window. Note: When dragging and dropping a COPY of the object will be made (instead of moving it) if the Ctrl key is held down when releasing the mouse button at the destination folder. To enable the ’Drag & Drop’ option double click the ’Drag & Drop’ message at the bottom of the Data Manager window.

10.2.5

The Data Manager Message Bar

The message bar shows the current status and settings of the database manager. Some of the messages are in fact buttons which may be clicked to change the settings. The message bar contains the following messages. • “Pause: on/off" (only in case of an opened input window) shows the status of the message queue in the input window. With pause on, the command interpreter is waiting which makes it possible to create a command queue. The message is a button: double-clicking it will toggle the setting. • “N object(s) of M" shows the number of elements shown in the browser window and the total number of elements in the current folder. • “N object(s) Selected:" shows the number of currently selected objects. • “Drag & Drop: on/off" shows the current drag & drop mode. Double clicking this message will toggle the setting.

10.2.6

Additional Features

Most of the data manager functionality is available through the context sensitive menus (right mouse button). The following items can also be found in the context sensitive menus: Show Reference List (Output... → Reference List) Produces the list of objects that have links, or references (plus the location of the linked object), to the selected object. The list is printed to the output window. In this manner for example, a list of elements that all use the same type can be produced. The listed object names can be double- or right-clicked in the output window to open their edit dialogue. Select All Selects all objects in the database browser. Mark in Graphic Marks the highlighted object(s) in the single line graphic. This feature can be used to identify an object. Show → Station Opens a detailed graphic (displaying all the connections and switches) of the terminal to which the selected component is connected. If the component, is connected to more than one terminal, as might be in the case of lines or other objects, a list of possible terminals is shown first. Goto Busbar Opens the folder in the database browser that holds the busbar to which the currently selected element is connected. If the element is connected to more than one busbar, a list of possible busbars is shown first.

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CHAPTER 10. DATA MANAGER Goto Connected Element Opens the folder in the database browser that holds the element that is connected to the currently selected element. In the case of more than one connected element, which is normally the case for busbars, a list of connected elements is shown first. Calculate Opens a second menu with several calculations which can be started, based on the currently selected objects. A short-circuit calculation, for example, will be performed with faults positioned at the selected objects, if possible. If more than one possible fault location exists for the currently selected object, which is normally the case for station folders, a short-circuit calculation for all possible fault locations is made. Other useful features: • Relevant objects for calculations are tagged with a check-mark sign (this will only be shown following a calculation). Editing one of these objects will reset the calculation results.

10.3

Defining Network Models with the Data Manager

In this section it is explained how the tools of Data Manager are used to define network models.

10.3.1

Defining New Network Components in the Data Manager

New network components can be directly created in the Data Manager. To do this you have to click on the target grid/expansion stage (right pane) to display its contents in the browser (left pane). Then you have to click on the New Object icon and select the kind of object to create. Alternatively you can directly enter the class name of the new component.

10.3.2

Connecting Network Components in the Data Manager

To connect newly created branch elements to a node, a free cubicle must exist in the target terminal. In the ’Terminal’ field (Terminal I and Terminal j for two port elements, etc.) of the edge element you have to click on the ( ) arrow to select (in the data browser that pops up) the cubicle where the connection is going to take place. To create a new cubicle in a terminal you have to open its edit dialogue (double click) and press the Cubicles button (located at the right of the dialogue). A new browser with the existing cubicles will and in the ’Element’ field select Cubicle (StaCubic). The edit pop up, press the New Object icon dialogue of the new cubicle will pop up; by default no internal switches will be generated. If you want a connection between the edge element and the terminal trough a circuit breaker, you have to press the Add Breaker button. After pressing the Ok button the new cubicle will be available to connect new branch elements. Note: New users are recommended to create and connect elements directly from the single line graphics. The procedures described above are intended for advanced users.

10.3.3

Defining Substations in the Data Manager

The concept and the application context of substations is presented in Section 4.7 (Project Structure). A description of the procedure used to define new substations with the data manager is given as follows. For information about working with substations in the graphical editor please refer to Section 9.2 (Defining Network Models with the Graphical Editor). 134

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10.3. DEFINING NETWORK MODELS WITH THE DATA MANAGER To define a new substation from the Data Manager do the following: • Display the content of the grid where you want to create the new substation. • Right click on the right pane of the Data Manager and select New → Substation from the context sensitive menu. • The new substation edit dialogue will pop up. There you can change the name, assign running arrangements and visualize/edit the content of the substation (directly after creation it is empty). • After pressing Ok the new substation and an associated diagram (with the same name of the substation) will be created. The components of the new substation can be created and connected using the associated single line diagram or using the data manager, the first option is recommended. For the second option, a data browser with the content of the substation will pop up after pressing the Contents button; there you can use the New Object icon to create the new components. Components of a substation can of course be connected with components of the corresponding grid or even with components of other networks. The connection in the Data Manager is carried out following the same procedure discussed in the previous section. For information about working with substations in the graphical editor please refer to Section 9.2 (Defining Network Models with the Graphical Editor). For information about the definition of Running Arrangements please refer to Section 12.3.6 (Running Arrangements).

10.3.4

Defining Composite Branches in the Data Manager

The concept and the application context of composite branches is discussed in Section 4.7 (Project Structure), and a description of how to define branches from within the diagram is provided in Section 9.2 (Defining Network Models with the Graphical Editor). This section provides a description of the procedure used to define new branches from within the Data Manager. Branches can be defined in the Data Manager as follows: 1. To create a Branch template, navigate to the Library → Templates folder in the Data Manager. 2. Right-click on the right pane of the Data Manager and select New → Branch from the context sensitive menu. 3. In the branch edit dialogue, define the name of the branch and press Ok. ´ 4. Now navigate back to the branch edit dialogue (right-click and SeditŠ, or double click), and select Contents to add terminal and line elements etc. to the template as required. The internal elements can be connected as discussed in Section 10.3.2. 5. Use the fields ’Connection 1’ and ’Connection 2’ to define how the branch is to be connected to external elements. 6. To create an instance of the Branch from the created Branch template, either: icon and connect the branch to existing terminals on the • Select the Composite Branch Single Line Diagram. • Select the Composite Branch icon and place the branch on the single line diagram, press Tab twice to place the branch without making any connections. Then connect the branch to ´ external elements by right-clicking and selecting SConnectŠ, or double-clicking the branch and selecting external connections for the relevant internal elements (e.g. lines). Select Update on in the Branch dialogue to update the external connections. Alternatively, for a single Branch (i.e. not using Templates) the branch can be defined in the grid folder. DIgSILENT PowerFactory 15, User Manual

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10.3.5

Defining Sites in the Data Manager

The concept and the application context of sites are presented in the Section 4.7 (Project Structure). Next a description of the procedure used to define new sites is given. To define a new site from the Data Manager do the following: • Display the content of the grid where you want to create the new site. • Right click on the right pane of the Data Manager and select New → Site from the context sensitive menu. • The new Site edit dialogue will pop up. • After pressing Ok the new site will be created. Note: Advanced users would notice that it is possible to move objects from a grid to a Substation, Branch, Site, etc. and vice versa.

10.3.6

Editing Network Components using the Data Manager

Each component can be individually edited by double clicking on it to open the corresponding dialogue. The class dialogue is composed of several tabs each corresponding to a calculation function of PowerFactory. The parameters required by a determined calculation are always available on the corresponding tab. The description of the network component’s models, explaining the relations among the input parameters is given in the technical reference papers attached to the Appendix C (Technical References of Models). It is possible to simultaneously edit components of the same class using the Data Manager. To do this you have to select a component of the class that you want to edit (left click on the component icon) and click on the Detail Mode icon at the upper part of the Data Manager. In ’detail’ mode, the browser shows all data fields for the selected calculation function data set, which can be selected by clicking on a tab shown at the bottom of the table view. If a page tab is out of reach, then the page tab scrollers will bring it within the browser window again. The list of objects may be sorted by any column by pressing the title field button. The widths of the data fields can be adjusted by pointing the mouse on the separation line between two title fields and dragging the field border by holding a mouse button down. The data fields can be edited by double-clicking them. As with any Spread Sheet, you can copy and paste individual or multiple cells with Crtl_C and Crtl_V or with right click ’ Copy/Paste. It is also possible to change a parameter field for more than one object simultaneously. The parameter fields which are going to be changed have to be multi-selected first, then you have to right-click the selection and select the option Modify Value(s) from the context sensitive menu. This will open the SetValue dialogue. This dialogue can be used to: • Increase or decrease them by multiplication with a scale factor (“Relative"). • Increase or decrease them by multiplication with a scale factor with respect to the sum of values selected (“Relative to Sum"). • Set all the selected parameter fields to a new fixed (“absolute") value. Note: It is not possible to simultaneously alter parameter fields from more than one column, i.e. to change nominal currents and nominal frequencies simultaneous, even if they would happen to take the same value or would have to be raised with the same percentage.

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10.4. SEARCHING FOR OBJECTS IN THE DATA MANAGER For further information please refer to 10.5 (Editing Data Objects in the Data Manager).

10.4

Searching for Objects in the Data Manager

There are three main methods of searching for objects in the data base: Sorting, searching by name and filtering.

10.4.1

Sorting Objects

Objects can be sorted according to various criteria, such as object class, name, rated voltage,..., etc. Sorting according to object class is done using the Edit Relevant Objects for Calculation icon on the toolbar ( ). The user may select a particular class of calculation-relevant object (e.g. synchronous machine, terminal, general load, but not graphics, user settings etc.) to be displayed in a browser. Further sorting can be done according to the data listed in a table- either in the data manager or in a browser obtained using the procedure described above. This is done by clicking on the column title. For example, clicking on the column title ’Name’ in a data browser sorts the data alphanumerically (A-Z and 1-9). Pressing it again sorts the data Z-A, and 9-1. Tabulated data can be sorted by multiple criteria. This is done by clicking on various column titles in a sequence. For example, terminals can be sorted alphanumerically first by name, then by rated voltage and finally by actual voltage by pressing on the titles corresponding to these properties in reverseˇ ˇ sequence (actual voltageErated voltageEname). A more detailed example follows: Suppose that you have executed a load flow calculation and that, for each rated voltage level in the network, you want to find the terminal with the highest voltage. These terminals could be identified easily in a table of terminals, sorted first by rated voltage and then by calculated voltage. Proceed as follows: • Perform the load flow calculation. • Select the ElmTerm

from the ’Edit Relevant Object for Calculation’ dialogue

.

• Include, in the Flexible Data page tab, the terminal voltage and nominal voltage (see 10.6). • In the table (Flexible Data page tab), click on the title ’u, Magnitude p.u’ to sort all terminals from highest to lowest calculated voltage. • Then click on the title ’Nom.L-L Volt kV’ to sort by nominal voltage level. • Now you will have all terminals first sorted by voltage level and then by rated terminal voltage.

10.4.2

Searching by Name

Searching for an object by name is done either in the right-hand pane of the data manager or in a data browser. To understand the procedure below, notice that the first column contains the symbols of the objects in the table. Clicking on such a symbol selects all columns of that row, i.e. for that object. The procedure is as follows: • Select an object in the table by clicking on any object symbol in the table (if one object was already selected then select a different one). • Now start typing the object name, which is case sensitive. Notice how the selection jumps as you type, For example, typing ’T’ moves the selection to the first object whose name starts with T, etc. • Continue typing until the selection matches the object that you are looking for DIgSILENT PowerFactory 15, User Manual

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10.4.3

Using Filters for Search

ˇ function . A filter is normally defined to find Advanced filtering capability is provided with the ’FindE’ a group of objects, rather than individual objects (although the latter is also possible). Advanced search criteria can be defined, e.g. transmission lines with a length in the range 1km to 2.2km, or synchronous machines with a rating greater than 500MW etc. ˇ in the data The function is available in both the data manager and a data browser. Clicking on ’FindE’ manager allows the user to apply a predefined filter or to define a new filter, called ’General filter’. If a ˇ in a new filter is defined, the database folder that will be searched can be defined. Clicking on ’FindE’ data browser allows the user to define a General Filter for objects within the browser. General Filters defined by the user are objects stored in the Changed Settings ∖ Filters folder. The options in the General Filter dialogue window are now explained with reference to Figure 10.4.1: Name: Name of filter. Object filter: This field defines either the complete or a part of the search criteria, and is optional. Examples are as follows: • • • • • •

*.ElmSym: Include element objects of the class synchronous machines. *.TypSym: Include type objects of the class synchronous machines. Lahney.*: Include all objects with the name Lahney. Lahney.Elm*: Include all element objects with the name Lahney. D*.ElmLod: Include all load element objects whose names start with D. A drop down list providing various object classes can be accessed with .

Look in: This field is available if a filter id defined within the data manager. It allows the user to specify the folder in the database that will be searched. Check boxes: • Include Subfolders will search the root folder specified as well as the subfolders in the root folder. The search can be stopped at the matching folder. • Relevant Objects for Calculation will include only those objects considered by the active study case (if no study case is active the search is meaningless and no search results will be returned). • Area Interconnecting Branches will search for branch elements that interconnect grids.

Figure 10.4.1: General Filter dialogue 138

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10.4. SEARCHING FOR OBJECTS IN THE DATA MANAGER The OK button will close the search dialogue, but save the filter object to the Changed Settings∖Filters folder. This makes it available for further use. The CANCEL button will close the dialogue without saving the changes. This button is useful if a search criterion (filter) will only be used once.The APPLY button starts the actual search. It will scan the relevant folders and will build a list of all objects that match the search criteria. Once the search is complete a list of results is returned in the form of a new data browser window. From this browser, the returned objects can be marked, changed, deleted, copied, moved, etc. . . . Advanced search options allow more sophisticated expressions as search criteria. These are specified in the Advanced page of the General Filter dialogue (Figure 10.4.2). The filter criterion is defined in terms of a logical expression, making use of parameter names. Objects will be included in the data browser if, for their parameters, the logical expression is determined to be true. An example of a logical expression is ’dline >0.7’. The variable dline refers to the length of a transmission line, and the effect of such a filter criterion is to limit the data in the browser to transmission lines having a length exceeding 0.7 km. The logical expressions can be expanded to include other relations (e.g. >=), standard functions (e.g. sin()), and logical operators (e.g. .and.). Note: Parameter names can be object properties or results. The parameter names for object properties are found, for example, by letting the mouse pointer hover over an input field in an object’s dialogue window. Parameter names for result variables are found from variable sets, which are described in Section 17.4 (Variable Sets).

Figure 10.4.2: Filter dialogue - Advanced

“Search Literally" is used to search for user defined strings ’inside’ parameter fields. For example, perhaps the comment ’damaged but serviceable’ has been entered for some elements in the network. This may be searched for as shown in Figure 10.4.3. All parameter fields will be searched for this string.

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Figure 10.4.3: Searching literally

As stated before, the objects matching the filter criteria are displayed in a data browser. They may also be highlighted in the graphic using the ’Color representation’ function described in Chapter 9: Network Graphics (Single Line Diagrams). The colour to be used in this case can be specified under the page ’Graphic’ of the General Filter dialogue window. Note: New a filters are saved to the Project∖Changed Settings∖Filters folder in the project and are available for use directly, using the right mouse menu. If a search is to be performed in a particular grid simply proceed as follows: right-click the grid folder → Find→ Local Filters→ Filter Name (e.g. Lines longer than 700m). Remember to press the Apply button to perform the search. If you unchecked the Show Filter Settings before Application box under User Settings → General then the filter will be applied as soon as it is selected from the menu. This is useful when you have already defined several filters for regular use.

10.5

Editing Data Objects in the Data Manager

The database manager (or Data Manager) offers several ways to edit power system components and other objects stored in the database, regardless they appear graphically or not. The basic method is to double-click the object icons in the database browser. This will open the same edit dialogue window obtained, when double clicking the graphical representation of an element in the graphic window.

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Figure 10.5.1: Full size edit window appearing after double-clicking the object icon in the data manager

An open edit dialogue will disable the data manager window from which it was opened. The edit dialogue has to be closed first in order to open another edit dialogue. However, it is possible to activate more than one data manager (by pressing the icon on the main toolbar) and to open an edit dialogue from each of these data managers. This can be useful for comparing objects and parameters. Using the edit dialogues (Figure 10.5.1) has one major drawback: it separates the edited object from the rest of the database, making it impossible to copy data from one object to the other, or to look at other object parameter values while editing. PowerFactory brings the big picture back in sight by offering full scale editing capabilities in the data managers browser window itself. The browser window in fact acts like a spreadsheet, where the user can edit and browse the data at the same time. The browser window has two modes in which objects can be edited, • Object mode • Detail Mode which are described in the following sections.

10.5.1

Editing in Object Mode

In the general case the icon, the name, the type and the modification date (with its author) of the objects are shown in the ’object’ mode (see Figure 10.5.2). Certain objects, for example network components, show additional fields like the “Out of Service" field.

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Figure 10.5.2: The browser window in ’object’ mode

The title buttons are used to sort the entries in the browser. The visible data fields can be double-clicked to edit their contents, or the F2 button can be pressed. The object will show a triangle in its icon when it is being edited. After the data field has been changed, move to the other fields of the same object using the arrow-keys or by clicking on these data fields, and alter them too. The new contents of a data field are confirmed by pressing the Return key, or by moving to another field within the same object. The triangle in the icon will change to a small star to show that the object has been altered. The object itself however has not been updated. Updating the changes is done by pressing Return again, or by moving to another object in the browser. By default, PowerFactory will ask to confirm the changes. See Section 10.2.5 (Data Manager Settings) to disable these conformation messages.

10.5.2

Editing in "Detail" Mode

If the icon on the browse window of the data manager is pressed, the browser changes to ’detail’ mode (see Figure 10.5.3). It will display only the objects from the same class as the one which was selected when the button was pressed. In the example of Figure 10.5.3, this is a load object (ElmLod). The icon or a filter (10.4.3) may also be used to engage detail mode.

Figure 10.5.3: The browser window in ’detail’ mode 142

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10.5. EDITING DATA OBJECTS IN THE DATA MANAGER In ’detail’ mode, the browser shows all data fields for the selected calculation function data set, which can be selected by clicking on a tab shown at the bottom of the table view.If a page tab is out of reach, then the page tab scrollers will bring it within the browser window again. The list of objects may be sorted by any column by pressing the title field button. The widths of the data fields can be adjusted by pointing the mouse on the separation line between two title fields and dragging the field border by holding a mouse button down. As with the browser in ’object’ mode, the data fields can be edited by double-clicking them. In the example the active power settings are being edited, but from the star in the object icon it is clear that another field of the same object has been edited too, but not confirmed, because this star would otherwise be a triangle. It is possible to change a parameter field for more than one object simultaneously. This is, for instance, useful to raise a certain limit for a range of objects, in order to get a better load-flow result i.e. by alleviating line overloads. An example is shown in Figure 10.5.4 where the nominal current for a range of lines is changed at once.

Figure 10.5.4: Modify values dialogue

Figure 10.5.5: Modify values dialogue

The parameter fields which have to be changed have to be multi-selected first. Right-clicking the selection will pop up a case sensitive menu from which the Modify Value(s) option opens the SetValue dialogue, see Figure 10.5.5. This dialogue can be used to:

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CHAPTER 10. DATA MANAGER • increase or decrease them by multiplication with a scale factor (“Relative"). • increase or decrease them by multiplication with a scale factor with respect to the sum of values selected (“Relative to Sum"). • Set all the selected parameter fields to a new fixed (“absolute") value. It is not possible to simultaneously alter parameter fields from more than one column, i.e. to change nominal currents and nominal frequencies simultaneous, even if they would happen to take the same value or would have to be raised with the same percentage.

10.5.3

Copy and Paste while Editing

One of the great advantages of editing data fields in the data manager’s browser window is the possibility to copy data from one object to another. This is done by selecting one or more objects or object fields, copying this selection to the clipboard, and pasting the data back in another place. To copy one or more objects, 1. Open the Data Manager and select the grid folder where you find the objects to be copied. Please do not open the icon for the Objects relevant for the calculation , as this is a filter view collecting objects stored at various locations. 2. Select them (see Figure 10.5.6). 3. Press Ctrl-C to copy or use the

icon on the data manager toolbox.

icon on the data manager toolbox. The objects will be copied 4. Press Ctrl-V to paste or use the with all the data. Their names will automatically be altered to unique names (see Figure 10.5.7).

Figure 10.5.6: Copying an object in the browser

Figure 10.5.7: Modify values dialogue

Copying data fields from one object to another is done just like for any spreadsheet software you may be familiar with. To copy one or more data fields, 1. Select them by clicking them once. Select more data fields by holding down the Ctrl key. 2. Copy the fields to the clipboard by pressing Ctrl-C or the

icon.

3. Select one or more target objects data fields. If more than one field was copied, make sure that the target field is the same as the first copied data field. 4. Press Ctrl-V or the 144

icon. The contents of the data fields will be copied to the target objects. DIgSILENT PowerFactory 15, User Manual

10.6. THE FLEXIBLE DATA PAGE TAB IN THE DATA MANAGER

10.6

The Flexible Data Page Tab in the Data Manager

The data browser (this will be seen in the data manager when the ’Detail Mode’ has been engaged) has page tabs for all calculation functions. These tabs are used to view or edit object parameters which are categorized according to a calculation function and have a fixed format. The ’Flexible Data’ tab, normally used to display calculation results, allows the user to define a custom set of data to be displayed. The default format for the calculation results displayed in the flexible page depends on the calculation performed: Following a load-flow calculation, the default variables for terminals are line-to-line voltage, per unit voltage and voltage angle. Following a short-circuit calculation the default variables are initial short-circuit current, initial short-circuit power, peak current etc. Figure 10.6.1 shows an example of the flexible data page tab.

Figure 10.6.1: The Flexible Data page tab

10.6.1

Customizing the Flexible Data Page

The displayed variables are organized in ’Variables Sets’ that are, in turn, organized according to the calculation functions. For example, an object class ElmTr2 (two-winding transformer) has a variable set for symmetrical load flow calculation, a variable set for short-circuit calculation etc. There may also be more than one variable set for any calculation function. For example, the object ElmTr2 may have two variable sets for symmetrical load flow calculation. The Flexible Page Selector allows the user to specify the variable set to use, or to define new variable sets. Furthermore, the Flexible Page Selector allows the user to access and edit the variable sets, i.e. to specify which variables to display in the Flexible Data page. The ’Flexible Page Selector’ dialogue is shown in Figure 10.6.2. This dialogue is opened by pressing the ( ) icon on the data manager toolbar. The Flexible Page Selector has a menu with all the different calculation functions. It opens in the page corresponding to the most recent calculation. The selection of variables within Variable Sets is presented in detail in Section 17.4 (Variable Sets).

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Figure 10.6.2: The Flexible Page Selector

The Format/Header tab (Figure 10.6.3) allows the user to customize the header of the Flexible Data page.

Figure 10.6.3: The Flexible Page Selector 146

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10.7. THE INPUT WINDOW IN THE DATA MANAGER

Note: Variable Sets are objects of class IntMon, within PowerFactory they have multiple uses. This section only presents their use in conjunction with Flexible Data. For further information please refer to Section 17.4 (Variable Sets).

The number format per column in the Flexible Data Page can also be modified by right clicking on the column header of the variable and selecting Edit Number Format . . . . A new window showed in figure 10.6.4 will appear and the user may define the number representation.

Figure 10.6.4: Number Format

10.7

The Input Window in the Data Manager

The input window is for the more experienced users of DIgSILENT PowerFactory . It is closed by default. Almost all commands that are available in PowerFactory through the menu bars, pop-up menus, icons, buttons, etc., may also be entered directly into the input window, using the PowerFactory commands. The contents of the input window can be saved to file, and commands can be read back into the window for execution. PowerFactory also has special command objects which carry one single command line and which are normally used to execute commands. In this way, complex commands can be saved in the same folder as the power system for which they were configured.

10.7.1

Input Window Commands

In principle, everything that can be done in DIgSILENT PowerFactory , can be done from the command line in the input window. This includes creating objects, setting parameters, performing load-flow or short-circuit calculations. Some commands that are available are typically meant for command line use or for batch commands. These commands are rarely used in another context and are therefore listed here as “command line commands", although they do not principally differ from any other command. Cd Command Moves around in the database tree by opening another folder at a relative position from the currently open folder. Example: cd...∖gridB∖Load1 Cl Command Stops the redirection of the output window to either a file or to a printer. All following DIgSILENT PowerFactory 15, User Manual

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CHAPTER 10. DATA MANAGER messages will again be shown only in the output window. cl/out stops redirection to a file cl/prn stops redirection to a printer Cls Command Clears the output or input window. cls/out clears output window cls/inp clears input window completely cls/inp/done clears only previously executed commands .../y asks for confirmation Dir Command Displays the contents of a folder. Example: dir Study Case Ed Command Pops up the dialogue of a default command, i.e. “ldf", “shc", etc. Example: ed ldf Exit Command Queries or sets a variable. Example: man/set obj=Load_1.elmlod variable=plini value=0.2 Op CommandC Redirects output to either a file or a printer. Example: op/out f=train3.out Pause Command Interrupts the execution of the command pipe until a next pause command is executed. Pr Command Prints either the contents of the output window or the currently active graphics window. Rd Command Opens and reads a file. Stop Command Stops the running calculation. Wr Command Writes to a file.

10.8

Save and Restore Parts of the Database

A selected part of the database can be written to a “DZ" Import/Export file with the button Export Data... . This will bring a ’File Save’ dialogue where a filename must be specified. Alternatively, the folder or object that is to be exported can be right-clicked in the database tree, after which the option Export... is selected. The exported part of the database may be a complete project, a library, or a specific object in the browser window. Exporting a folder (i.e a project, grid, library, etc.) will export the complete content of that folder, inclusive subfolders, models, settings, single line graphics, etc. It is even possible to export a complete user account. However, only the administrator is able to import an user-account. Exporting the user-account on a regular basis is a practical way to backup your data. It is even possible to export data from another user account, or even to export another user-account completely. However, only the shared, visible, data will be exported. The exported data file can be imported into the database again in any desired folder by pressing the Import Data... button. This will bring a ’File Open’ dialogue where the “DZ" data-file can be selected. 148

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10.9. SPREADSHEET FORMAT DATA IMPORT/EXPORT The “DZ"-file will be analyzed and error messages will be displayed when the file is not a genuine PowerFactory data file, or if it is corrupted. If the file format has been found to be correct, a dialogue will appear which shows the data and version of the file. The default target folder is shown also, which is the original folder of the saved data. If this is not desired, another target folder can be selected by pressing the Drop Down button. This button will bring a small version of the database tree. A new target folder can be selected from this tree.

10.8.1

Notes

By exporting a folder from the database, only the information in that folder and all its subfolders will be stored. If the exported objects use information (e.g. power system types like line or transformer types) that is saved somewhere else, then that information will not be stored. Make sure that the used power system types and all other referenced information is exported too. When importing a file that contains objects which use data outside the import-file, a search for that data is started. For instance, assume a project is exported. One of the line-models uses a type from a library outside the project. When exporting, the path and name of this type is written in the export-file, but the type itself is not exported, as is does not reside in the exported project. At importing, the stored path and name of the ’external’ type is used to find the type again and to restore the link. However, if the ’external’ type is not found, then it will be created, using the stored path and name. Of course, the created object has default data, as the original data was not exported. Additionally, an error message is written to the output window. Suppose that you are working with a large library, which is stored in a special user-account to make it read-only. The library is made accessible by sharing it to all users. When export the projects, the objects from the external library are not exported. However, a colleague which has access to the same library may still import your projects without problems. The external objects used in your projects will be found in the same location, and the links to these objects will be correctly restored.

10.9

Spreadsheet Format Data Import/Export

The PowerFactory data browser in the data manager’s window looks and acts like a spreadsheet program as far as creating and editing power system objects is concerned. To enable and simplify the use of power system element data which is stored in spreadsheet programs such as the Microsoft Excel or the Lotus 123 programs, the data browser offers ’Spreadsheet Format’ import and export facilities.

10.9.1

Export to Spreadsheet Programs (e. g. MS EXCEL)

All data visible in the data browser may be exported as it is. The export format is such that most common spreadsheet programs can read in the data directly (space separated ASCII). Exporting data is performed as follows. • Select a range of data in the data browser. Such a range may contain more than one column and more than one row. • Right-click the selected range. • Now you have different options:

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CHAPTER 10. DATA MANAGER – If you want to copy the content of the marked cells only, simply select Copy from the contextsensitive menu. – If you want to copy the content of the marked cells together with a description header, select the Spread Sheet Format option. This opens a second menu which offers the choice between writing the Spreadsheet export to a file (Write to File), or to put it on the Windows Clipboard (Copy (with column headers)). See Figure 10.9.1. • The exported data can now be imported into a Spreadsheet program. When the Clipboard was used, using the Paste option of the spreadsheet program or pressing Ctrl-V will Paste the data into the spreadsheet. • The imported data may now be edited, or additional calculations may be made. The PowerFactory data is imported as numbers and descriptions. The example in Figure 10.9.2 calculates a mean value from a range of line loading percentages.

Figure 10.9.1: Exporting a range of data

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Figure 10.9.2: Imported data in a spreadsheet program

10.9.2

Import from Spreadsheet Programs (e. g. MS EXCEL)

There are two methods available for importing data from a spreadsheet program. The first method uses a direct import of ’anonymous’ numerical data, i. e. of the values stored in the cells of the table. This method is used to change parameter of existing objects by importing columns of parameter values. The second method can be used to create new objects (or replace whole objects) by importing all the data from a spreadsheet. Any range of parameter values can be copied from a spreadsheet program and imported into the database manager. The import is performed by overwriting existing parameter values by ’anonymous’ values. The term ’anonymous’ expresses the fact that the imported data has no parameter description. The size of the imported value range and the required data are tested. Importing invalid values (i.e. a power factor of 1.56) will result in an error message. Spreadsheet Import of Values The import of values (anonymous variables), i. e. cells of a table, is explained by the following example. In Figure 10.9.3, a range of active and reactive power values is copied in a spreadsheet program. In Figure 10.9.4, this range is pasted to the corresponding fields of 6 load objects by right-clicking the upper left most field which is to be overwritten. The result of this action is shown in Figure 10.9.5. In contrast to the import of whole objects, the anonymous import of data does not need a parameter description. This would complicate the import of complete objects, as the user would have to enter all parameters in the correct order.

Figure 10.9.3: Copying a range of spreadsheet data

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Figure 10.9.4: Pasting spreadsheet data from clipboard

Figure 10.9.5: Database browser with imported data

Spreadsheet Import of Objects and Parameters With this kind of import, it is possible to import whole objects (in contrast to the import of pure values, which is described above). The object import uses a header line with the parameter names (which is necessary in addition to the cells with the pure values). This header must have the following structure: • The first header must be the class name of the listed objects. • The following headers must state a correct parameter name. This is shown in Figure 10.9.6.

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Figure 10.9.6: DExcel required format

Figure 10.9.7 shows an example of valid spreadsheet data of some line types and some 2-winding transformer types.

Figure 10.9.7: Example of valid spreadsheet data

The import of the spreadsheet data into PowerFactory is performed as follows. • Select the header line and one or more objects lines. • Copy the selection. See Figure 10.9.8 for example. • Right-click the folder browser in the database manager to which the objects are to be imported. Select Spread Sheet Format → Import Objects from Clipboard. See Figure 10.9.9 for example.

Figure 10.9.8: Selecting object data in spreadsheet

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Figure 10.9.9: Importing objects from clipboard

The result of the object import depend on whether or not objects of the imported class and with the imported names already exist or not in the database folder. In the example of Figure 10.9.10, none of the imported objects existed in the database an all were created new therefore. The example shows the database in detail mode.

Figure 10.9.10: Result of spreadsheet object import Note: New objects are created in the PowerFactory database folder only when no object of the imported class and with the imported name is found in that folder. If such an object is found then its data will be overwritten by the imported data

Because new objects are only created when they do not exist already, and only the imported parameters are overwritten when the object did exists already, the import is always a save action. Remarks Object Names Object names may not contain any of the characters * ?=",∖∼| 154

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10.9. SPREADSHEET FORMAT DATA IMPORT/EXPORT

Default Data When an imported object is created newly, the imported data is used to overwrite the corresponding default data. All parameters that are not imported will keep their default value. Units The spreadsheet values are imported without units. No conversion from MW to kW, for example, will be possible. All spreadsheet values therefore have to be in the same units as used by PowerFactory.

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Chapter 11

Study Cases 11.1

Introduction

The concept of Study Cases was introduced in Chapter 4 (PowerFactory Overview). Study Cases (IntCase, ) define the studies to be performed in the modelled system. They store all the definitions created by the user to perform calculations, allowing the easy reproduction of results even after the deactivation of the project. By means of the objects stored inside them objects the program recognizes: • The parts of the network model (grids and expansion stages) to be considered for calculation. • The calculations (and their settings) to be performed over the selected parts of the network. • The study time. • The active variations. • The active operation scenario. • The calculation results to be stored for reporting. • The graphics to be displayed during the study. A study case with a reference to at least one grid or expansion stage has to be activated in order to enable calculations. A project that contains more than one grid, which has several expansion stages for design alternatives, or which uses different operation scenarios to model the various conditions under which the system should operate, requires multiple study cases. All the study cases of a project are stored inside the ’Study Cases’ folder ( ) in the project directory. Note: Only one study case can be active. When activating a study case, all the grids, variations and operation scenarios that it refers become active.

Without study cases, it would be necessary to manually activate the correct grid and/or expansion stage over and over again in order to analyze the resulting power system configuration. Similarly, it would be necessary to define over and over again the same calculation command setup used to analyze the behaviour of the selected network. Besides storing the objects that define a network study, study case objects set the output units for the performed calculations and allow the definition of certain calculation options for the solving algorithms. The following sections describe the main objects stored inside the study cases, as mentioned before they are used to define the network studies. For information about defining and working with study cases please refer to Section 11.2 (Creating and Using Study Cases). DIgSILENT PowerFactory 15, User Manual

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11.2

Creating and Using Study Cases

When a new project is created, a new empty study case is automatically generated and activated. The new study case is assigned the default settings of PowerFactory. The user can later edit them using the study case dialogue (Figure 11.5.1). The user may define several study cases to facilitate the analysis of projects containing more than one grid, several expansion stages, different operation scenarios or simply different calculation options. To create a new study case: • Open the Data Manager and go to the Study Cases folder. Right-click the folder and select New → Study Case from the context sensitive menu. Enter the name of the new case in the dialogue that pos up (Figure 11.5.1) and edit (if required) the default settings. Only one study case can be active at any time. To (de)activate a study case: • Open the Data Manager. The active study case and the folder(s) where it is stored are highlighted. Right-click on the active study case and choose Deactivate from the context sensitive menu. To activate a dormant study case place the cursor on its name, right-click and choose Activate. Study cases may also be activated in the Project Overview Window (see Figure 11.2.1).

Figure 11.2.1: Activating a study case from the Project Overview Window

A study case can have more than one grid. Only the objects in the active grids will be regarded in the calculations. To add an existing grid to the active study case: • Open the data manager and go to the Network Data folder. Right-click the grid you want to add to your calculation and select Add to Study Case from the context sensitive menu. The grid will be activated and graphics will be opened (after a selection by the user). To remove an active grid, select Remove from Study Case. Variations are considered by a study case when they are activated. The expansion stages are applied according to the study case time, which is set by the time trigger stored inside the study case folder. More than one variation can be active for a study case. However there will always be only one recording stage. For further information, please refer to Chapter 15 (Network Variations and Expansion Stages). To add (activate) a variation to the active study case: • Right-click on it and select Activate from the context sensitive menu. The variation will be activated and stages will be highlighted depending on the study time. An operation scenario can be (de)activated via context menu or using the option File → Activate Operation Scenario/ Deactivate Operation Scenario from the main menu. On activation, a completeness 158

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11.3. SUMMARY GRID check is done (check if operational data is available for all components). This is reported in the PowerFactory output window. If an operation scenario is active, all operational data attributes in property sheets or in data manager are highlighted in a blue colour. This indicates that changes of these values will not modify the base component (or variation) but are recorded by the active operation scenario. On deactivation, previous operational data are restored. If the operation scenario was modified, a user confirmation is requested whether to save the changes or to discard them. For further information about working with operation scenarios, please refer to Chapter 14 (Operation Scenarios). Note: Only one study case can be activated at a time. Although network components and diagrams can be edited without an active study case, calculations can not be performed unless a study case is activated. Variations and operation scenarios used by a study case are automatically activated with the corresponding study case.

11.3

Summary Grid

The primary task of a Study Case is to activate and deactivate a calculation target, which is a combination of grids and optionally expansion stages from the Network Model. The Summary Grid object holds references to the grids which are considered in the calculation (that is the active grids). Grids may be added to, or removed from, the study case by right-clicking them in the database tree and selecting Add to Study Case or Remove from Study Case from their edit dialogue. Automatically a reference to the activated/deactivated grid is generated/deleted in the Summary Grid object. A grid cannot be activated separately; a study case linked to the grid must be active. The context sensitive menu will show an Activate option when a grid or system stage folder is right-clicked if no study case folder is active. This will present a prompt dialogue which request that either an existing study case be activated, or a new study case be created first. The grid or system stage is then activated in conjunction with whichever choice is made.

11.4

Study Time

PowerFactory Version 14 extends the idea of a model into the dimension of time. The Study Case has got a Study Time. The Study Time defines the point in time you wish to analyze. The Study Time must be inside the Validity Period of the Project, which specifies the time span the Project is valid for (see Chapter 8: Basic Project Definition, Section 8.1.3 (Project Settings)). PowerFactory will use the Study Time in conjunction with time-dependent network expansions (see Chapter 15: Network Variations and Expansion Stages) to determine which network data is applicable to that point in time. You are able to change the Study Time in order to analyze a different point in time. The Expansion Stages will be activated/deactivated with the Study Time. The status bar at the bottom of the PowerFactory program window shows the currently set Study Time. The most easy way to change the Study Time is: • Double click on the Study Time shown in the status bar of PowerFactory. • Enter the date and time or press the button → Date and→ Time in order to set the Study Time to the current time of your computer. • Press OK to accept the changes and close the window. There are several alternative ways to edit the Study Time. Alternative 1: Edit the Study Time like a Trigger: DIgSILENT PowerFactory 15, User Manual

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CHAPTER 11. STUDY CASES • Press the button Date/Time of Calculation Case in the main toolbar of PowerFactory. • Enter the date and time or press the button → Date and→ Time in order to set the Study Time to the current time of your computer. • Press OK to accept the changes and close the window. Alternative 2: Edit the Study Case from within the Study Case dialogue: • Activate the project and browse for the Study Case in the Data Manager. • Right click on the Study Case and select Edit from the context sensitive menu. • On the Basic Data page press the button with the three dots beneath the entry for the Study Time • Set the Study Time according to your needs. • Press OK to accept the changes and close the window.

11.5

The Study Case Edit Dialogue

To edit the settings of a study case, you may select Edit → Study Case in the main menu, or right-click the study case in the Data Manager and select Edit from the context sensitive menu. A dialogue as shown in Figure 11.5.1 will appear.

Figure 11.5.1: Study Case edit dialogue

In the Basic Data page, the user can define the name and an owner to the study case. The output units of the calculated variables are defined in the Output Variables field. The grids that are linked to a study case may be viewed by pressing the Grids/System Stages button. The study time can be edited by pressing the button; this will open the edit dialogue of the study case time trigger (see Section 15.4: Study Time). Please regard that the study time can also change as a result of setting the recording expansion stage explicitly (see Chapter 15: Network Variations and Expansion Stages). The Calculation Options page is used to set the solving algorithm for the case calculations. The change of the default options is only recommended under the supervision of the DIgSILENT support experts. The Description page, like all object’s description pages is used to add user comments. Note: To edit the study time you can alternatively, press on the “Date/Time of Calculation Case" button . This will open the study case time trigger window. Also, at the lower right corner of the screen 160

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11.6. VARIATION CONFIGURATION the time of the simulation case is displayed. By double-clicking on this field you are taken to the same window.

11.6

Variation Configuration

Similarly to the Summary Grid object, the Variation Configuration object (IntAcscheme ences to the active variations.

11.7

) holds refer-

Operation Scenarios

A reference to the active operation scenario (if any) is always stored in the study cases. Similar to variation configurations and summary grids, when a study case is activated, the operation scenario (if any) whose reference is hold, will be automatically activated. The reference to the active operation scenario is automatically updated by the program.

11.8

Commands

In PowerFactory a calculation (i.e load flow , short circuit , initial conditions of a time domain simulation , etc.) is performed via ’Calculation Commands’, which are the objects that store the calculation settings defined by the user. Each study case stores its own calculation commands, holding the most recent settings. This ensures consistency between results and calculation commands and enables the user to easily reproduce the same results at a later stage. When a calculation is performed in a study case for the first time, a calculation command of the corresponding class is automatically created inside the active study case. Different calculation commands of the same class (i.e different load flow calculation commands: objects of the class ComLdf or different short circuit calculation commands: objects of the class ComShc ) can be stored in the same study case. These approach allows the user to repeat any calculation, with all the settings (such as fault location, type, fault impedance, etc.) as last performed in the study case. Of course the calculations are performed only over the active grids (expansion stages). Figure 11.8.1 shows a study case called Study 1 witch contains two load flow calculation commands ( , Ldf 1 and Ldf2), one command for an OPF calculation , one command for the calculation of , and one transient simulation . The edit dialogue of each one of the calculainitial conditions tion commands existing in PowerFactory is described in the chapter corresponding to that calculation function.

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Figure 11.8.1: Calculation Commands in a Study Case

Actions such as generating a report of the actual calculation results or the state of the defined network components are carried out via command objects (in this case ComSh and ComDocu objects respectively). For information about reporting commands please refer to Chapter 17 (Reporting and Visualizing Results). Note: Command objects basically consist of the data set that configures the calculation, and the Execution function to perform the computations. Like any other object calculation commands can be copied, pasted, renamed and edited.

11.9

Events

Simulation Events objects are used to define simulation events. For time-domain simulations, events are stored within the Study Case → Simulation Events/Fault folder (see Chapter 26: Stability and EMT Simulations, Section 26.6 for a general description). For short-circuit studies, they are stored in the Study Case → Short Circuits folder. For other steady-state calculations that utilize Simulation Events, they are stored within the Operational Library → Faults folder. PowerFactory offers several kinds of events: • Dispatch Event (EvtGen) • External Measurement Event (EvtExtmea) • Intercircuit Fault Events (EvtShcll) • Events of Loads (EvtLod) • Message Event (EvtMessage) • Outage of Element (EvtOutage) • Parameter Events (EvtParam) • Save Results (EvtTrigger ) • Short-Circuit Events (EvtShc) • Stop Events (EvtStop)

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11.9. EVENTS • Switch Events (EvtSwitch) • Synchronous Machine Event (EvtSym) • Tap Event (EvtTap)

11.9.1

Dispatch Event

The user specifies the point in time in the simulation for the event to occur, and a generation element (ElmSym, ElmXnet or ElmGenstat). The incremental change of the generator can then be altered using the dispatch event.

11.9.2

External Measurement Event

External measurement events can be used to set and reset values and statuses of external measurement objects.

11.9.3

Intercircuit Fault Events

This type of event is similar to the short-circuit event described in Section 11.9.9 (Short-Circuit Events (EvtShc)). Two different elements and their respective phases are chosen, between which the fault occurs. As for the short-circuit event, four different elements can be chosen: • Busbar (StaBar ) • Terminal (ElmTerm) • Overhead line or cable (ElmLne)

11.9.4

Events of Loads

The user specifies the point in time in the simulation for the event to occur, and a load element(s) (ElmLod, ElmLodlv, ElmLodmv or ElmLodlvp). The value of the load can then be altered using the load event. The power of the selected load(s) can be changed as follows: • Step Changes the current value of the power (positive or negative) by the given value (in % of the nominal power of the load) at the time of the event. • Ramp Changes the current value of the power by the given value (in % of the nominal power of the load), over the time specified by the Ramp Duration (in seconds). The load ramping starts at the time of the event.

11.9.5

Message Event

A message will be printed to the output window at the specified time in the simulation.

11.9.6

Outage of Element

This Outage of Element event can be used to take an element out of service at a specified point in time. It is intended for use in steady-state calculations e.g. short-circuit calculation and reliability assessment. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 11. STUDY CASES It may also be used to take elements out of service in time-domain simulations, however it is not possible to bring an outaged element back into service using this event during a transient simulation. This is only possible in steady-state calculation functions. The following message will be displayed if the user attempt to bring a previously outaged element back into service using Outage of Element: DIgSI/err (t=000:000 ms) - Outage Event in Simulation not available. Use Switch-Event instead!

11.9.7

Parameter Events

With this type of event, an input parameter of any element or DSL model can be set or changed. First, a time specifying when the event will occur is specified. Then an element has to be to specified/selected . Then choose Select... from the context-sensitive menu. Afterwards using the down-arrow button insert the name and the new value of a valid element parameter.

11.9.8

Save Results

This event is only used for PowerFactory Monitor applications. It cannot be used during time-domain simulations.

11.9.9

Short-Circuit Events

This event applies a short-circuit on a busbar, terminal or on a specified point on a line. The fault type (three-phase, two-phase or single-phase fault) can be specified as well as the fault resistance and reactance and the phases which are affected. The duration of the fault cannot be defined. Instead, to clear the fault, another short-circuit event has to be defined, which will clear the fault at the same location.

11.9.10

Stop Events

Stops the simulation at the specified time within the simulation time-frame.

11.9.11

Switch Events

Switch events are used only in transient simulations. To create a new switch event, press the icon on the main menu (if this icon is available), which will open a browser containing all defined simulation events. Click on the icon in this browser, which will show a IntNewobj (Figure 11.9.1) dialogue which can be used to create a new switching event.

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11.10. SIMULATION SCAN

Figure 11.9.1: Creation of a New Switch Event (IntNewobj)

After pressing OK, the reference to the switch (labelled Breaker or Element) must be manually set. Any switch in the power system may be selected, thus enabling the switching of lines, generators, motors, loads, etc. The user is free to select the switches/breakers of all phases or of only one or two phases. It should be noted that more than one switching event must be created if, for instance, a line has to be opened at both ends. These switch events should then have the same execution time.

11.9.12

Synchronous Machine Event

The Synchronous Machine Event is used to easily change the mechanical torque of a synchronous machine (ElmSym). The user specifies the point in time in the simulation for the event to occur, and an active synchronous machine. The user can then define the additional mechanical torque supplied to the generator. The torque can be positive or negative and is entered in per unit values.

11.9.13

Tap Event

The user specifies the point in time in the simulation for the tap event to occur, and a shunt or transformer element (ElmShnt, ElmTr2, etc). The Tap Action can then be specified.

11.10

Simulation Scan

For details of Simulation Scan modules, refer to Chapter 26 Section 26.5.

11.11

Results Objects

The Results object (ElmRes ) is used to store tables with the results obtained after the execution of a command in PowerFactory. The typical use of a Results object is in writing specific variables during a transient simulation, or during a data acquisition measurement. The obtained results can later be used to generate plots, or in DPL scripts. An example of the result object dialogue is depicted in Figure 11.11.1. DIgSILENT PowerFactory 15, User Manual

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Figure 11.11.1: The Results Object Dialogue

The result object shows the following fields: Name The name of the result object Database ID Its database ID and the date, when it was changed the last time Default for Its default use Info Information about the currently stored data, ie.e the time interval, step sizes, number of variables, etc. Trigger-Times Trigger times (in case of a Triggered default use) The information about the stored data shows: • The time interval. • The average time step. • The number of points in time. • The number of variables. • The size of the database result-file. The Clear Data will clear all result data (only available if calculation results are stored). Note: Clearing the data will delete the result-file and will reset the database ID. This will destroy all calculated or measured data in the result file. It will not be possible to restore the data.

The content of a result object (the variables whose results are stored) is determined by sets of selected variables called Monitor Variable Sets (IntMon ). Each Monitor Variable Set stores the results of the selected variables for one network component. These monitor objects can be edited by pressing the Variables button. This will show the list of monitor sets currently in use by the result object. Note: Selecting a set of result variables, trough the use of monitor objects is necessary because otherwise all available variables would have to be stored, which is practically impossible.

When the Export button is pressed, all events that happened during the simulation, could be exported in different formats. For information about exporting results, please refer to Chapter 17: Reporting and Visualizing Results, Section 17.2.4 (Result Objects). 166

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11.12. VARIABLE SETS

11.12

Variable Sets

The result object combines one or more monitor variable sets (IntMon ), allowing a very flexible and highly transparent result definition. In fact, by using monitor variable sets, just about every parameter used in the PowerFactory program comes available as calculation result, together with a description and a unit. The variables selected with the IntMon dialogue in the result object become available to the subplot objects in the virtual instrument panels. In these plots, one or more result objects can be selected and from those result objects a power system element and one of its variables can be chosen, if that element and that variable was selected in one of the IntMon objects. The subplot will then show the calculated curve of that variable. Variable sets always have a reference to a network component, whose selected variables are going to be recorded (Figure 11.12.1 red circle, in this case a transformer called EBT1). To facilitate the selection of the variables, monitor variable sets are organized according to the calculation functions of PowerFactory and by the type of data. For example, if the results of a harmonics calculation are to be recorded, the user should go to the Harmonics/Power Quality page (Figure 11.12.1, green circle). If the voltage or the power of the referred element is to be stored, the selected ’Variable Set’ should be Currents, Voltages and Powers (Figure 11.12.1 blue circle).

Figure 11.12.1: Monitor Variable Set Dialogue

For further information about the definition of Monitor Variable Sets please refer to Chapter 17: Reporting and Visualizing Results, Section 17.4 (Variable Sets).

11.13

Triggers

As described in Chapter 16 (Parameter Characteristics, Load States, and Tariffs), parameter characteristics are used to define parameters as ranges of values instead of fixed amounts. The parameter characteristics are set over user defined scales. The current value of the parameter is at the end deterDIgSILENT PowerFactory 15, User Manual

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CHAPTER 11. STUDY CASES mined by a trigger object (SetTrigger, ), which sets a current value on the corresponding scale. For example if the value of a certain parameter depends on the temperature, a characteristic over a temperature scale is set. The current value of the temperature is defined by the trigger. The current value of the temperature determines the current value of the parameter, according to the defined characteristic. Once a parameter characteristic and its corresponding scale are set, a trigger pointing to the scale is automatically created in the active study case. The user can access the trigger object and change its actual value every time that he/she requires. PowerFactory offers different types of characteristics and scales; each scale (by default scales are stored in the Scales folder of the Equipment Library) points to a trigger from the active study case. Information about the use and definition of characteristics, scales and triggers is given in Chapter 16 (Parameter Characteristics, Load States, and Tariffs).

11.14

Graphic Board

) where refThe Study Case folder contains a folder called the Graphics Board folder (SetDesktop, erences to the graphics to be displayed are contained. This folder, much like the Summary Grid folder, is automatically created and maintained and should generally not be edited by the user. The references in the graphics board folder are created when the user adds a grid to a study case. PowerFactory will ask the user which graphics of the grid should be displayed. At any time later the user may display other graphics in the grid by right-clicking the grid and selecting Show Graphic. Graphics may be removed by right-clicking the tab at the bottom of the page and selecting Remove Page(s). The study case and graphics board folder will also contain references to any other graphics that have been created when the study case is active.

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Chapter 12

Project Library 12.1

Introduction

The project library stores the following categories of data: • Equipment Types (Section 12.2: Equipment Type Library) • Operational Data (Section 12.3: Operational Library) • DPL Scripts (See Chapter 19: The DIgSILENT Programming Language - DPL) • Table Reports (See Appendix D, section D.5.8 Table Report Methods) • Templates (Section 12.4: Templates Library). • User Defined Models (See Section 26.11: User Defined (DSL) Models) This chapter is describes the Equipment Type Library, Operational Library, and Templates library. Note that in addition to the project Library, the global Library includes a range of pre-defined types, models, templates, and scripts (refer to Chapter 4: PowerFactory Overview, Section 4.6: Data Arrangement for details).

12.2

Equipment Type Library

The Equipment Type Library is used to store and organize Type data for each class of network component. Once a new project is created, an Equipment Type Library is automatically set by the program within the Library folder. It also includes a subfolder for storing Scales. To create or edit a folder in the Equipment Type Library : 1. On the Equipment Type Library folder in the left pane of the Data Manager right-click and select New → Project Folder from the context sensitive menu (or to edit an existing folder, right-click the folder and select Edit). The project folder edit dialogue is displayed. 2. In the Name field, enter the name of the new folder. 3. In the Folder Type field, select Generic. 4. In the Class Filter field, write the name of the type class(es) to be allowed in the folder (case sensitive). If more than one class is to be allowed, write the class names separated by commas. An asterisk character (* ) can be used to allow all classes. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 12. PROJECT LIBRARY 5. In the Icon field, select Library. and select the appropriate To create new type objects in these folders select the New Object icon type class. Alternatively, types can be copied from other projects or the global library. If the type class does not match the folder filter, an error message is displayed. Within the Equipment Type Library, the Scale folder is used to store the Scales used by the parameter characteristics. Refer to Chapter 16 (Parameter Characteristics, Load States, and Tariffs) for details. Note: By default new block definitions (used by dynamic models) created from block diagrams are also stored in the Equipment Types Library. Chapter 26 (Stability and EMT Simulations) provides details related to dynamic modelling and block definitions.

Figure 12.2.1 shows the equipment library of a project containing generator, load, and transformer types, sorted using library sub-folders.

Figure 12.2.1: The Equipment Library

Unlike the “Global Library", which is accessible to all users, the local Equipment Type Library is used to define types that are to be used in the specific project. It can only be used by the project owner, and users with which the project is shared. There are three options available for defining Type data for network components, as illustrated in (Figure 12.2.2): 1. Select Global Type from the Global Library. The Data Manager is launched in the “Global Library". 2. Select Project Type. The Data Manager is launched in the local Equipment Type Library. 3. New Project Type. A new type will be defined and automatically stored in the local Equipment Type Library. Note that Global Types and Project Types buttons can be used to quickly switch between the global and local libraries (Figure 12.2.2).

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Figure 12.2.2: Selecting a Synchronous Machine Type

12.3

Operational Library

The Operational Library is used to store and organize operational data for application to a number of elements, without the need to duplicate operational information. To illustrate, consider an example where there are two generators, “G1" and “G2". The units have slightly different Type data, and thus unique Type models, “G 190M-18kV Ver-1" and “G 190M-18kV Ver-2". The Capability Curves for these units are identical, and so the user wishes to create only a single instance of the capability curve. By defining a Capability Curve in the Operational Library, a single Capability Curve can be linked to both generators. Similarly, various circuit breakers may refer to the same short-circuit current ratings. A Circuit Breaker Rating object can be defined in the Operational Library and linked to relevant circuit breakers This section describes the definition and application of operational data objects.

12.3.1

Circuit Breaker Ratings

(IntCbrating) contain information that define the rated short-circuit Circuit Breaker Ratings objects currents of circuit breakers (objects of class ElmCoup). They are stored inside the CB-Rating folder in the Operational Library. Any circuit breaker (ElmCoup) defined in the Network Model can use a reference to a Circuit Breaker Rating object in order to change its current ratings. The parameters defined by a circuit breaker rating are: • Three phase initial peak short circuit current. • Single phase initial peak short circuit current. • Three phase peak break short circuit current. • Single phase peak break short circuit current. • Three phase RMS break short circuit current. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 12. PROJECT LIBRARY • Single phase RMS break short circuit current. • DC time constant. To create a new circuit breaker rating in the operational library: • In the data manager open the CB Ratings folder. • Click on the New Object icon

.

• In the Element Selection dialogue select Circuit Breaker Rating (IntCbrating) and press Ok. • The new circuit breaker rating dialogue will then be displayed. Set the corresponding parameters and press Ok. To assign a circuit breaker rating to a circuit breaker (ElmCoup object) from the network model: 1. Go to the Complete Short-Circuit page of the element’s dialogue. 2. In the Ratings field click on the

button to select the desired rating from the CB Ratings folder.

The parameters defined in the circuit breaker ratings can be made to be time-dependant by means of variations and expansion stages stored inside the CB Ratings folder. For information regarding short-circuit calculations, refer to Chapter 22 (Short-Circuit Analysis). For further information about variations and expansion stages, refer to Chapter 15(Network Variations and Expansion Stages). Note: Variations in the CB Ratings folder act ’locally’, they will only affect the circuit breaker ratings stored within the folder. Similarly, the variations of the Network Model will only affect the network components from the grids.

Note: Circuit breaker elements (ElmCoup) must be distinguished from Switch objects (StaSwitch); the latter are automatically created inside cubicles when connecting a branch element (which differs to a circuit breaker) to a terminal. Ratings can also be entered in the StaSwitch Type object.

Example Time-Dependent Circuit Breaker Rating Consider an example where a substation circuit breaker “CB" operates with different ratings depending on the time of the year. From 1st January to 1st June it operates according to the ratings defined in a set of parameters called “CBR1". From 1st June to 31st December it operates with the ratings defined in a set of parameters called “CBR2". This operational procedure can be modelled by defining a circuit breaker rating “CBR" in the CB Ratings folder, and a variation “CB_Sem_Ratings" containing two expansion stages. The first expansion stage should activate on the 1st January and the second on the 1st June. The first task is the definition of the time-dependant circuit breaker rating “CBR". To set the parameters of “CBR" for the first period: 1. Set a study time before the 1st June to activate the first expansion stage (the Variation “CB_Sem_Ratings" must be active). 2. Edit the parameters of “CBR" (previously defined) according to the values defined in “CBR1". The new parameters will be stored in the active expansion stage. 3. To set the parameters of “CBR" for the second period: 172

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12.3. OPERATIONAL LIBRARY 4. Set a study time after the 1st June to activate the second expansion stage; 5. Edit “CBR" according to the values of “CBR2". The new parameters will be stored in the active expansion stage. Once the ratings for the two expansion stages have been set, and the circuit breaker rating “CBR" has been assigned to the circuit breaker “CB", the study time can be changed from one period to the other to apply the relevant ratings for “CB" (note that the variation must be active).

12.3.2

Demand Transfers

The active and reactive power demand defined for loads and feeders in the network model can be transferred to another load (or feeder) within the same system by means of a Demand Transfer (objects class IntOutage). This transfer only takes place if it is applied during a validity period defined by the user (i.e. if the current study time lies within the validity period). To create a new load demand transfer: 1. In the data manager, open the Demand Transfer folder. 2. Click on the New Object icon

.

3. In the Element Selection dialogue select Planned Outage (IntOutage) and press Ok. 4. Set the validity time, the source and target loads/feeders and the power transfer. Note: If there is a demand transfer, which transfers load between two loads (ElmLod) belonging to different feeders (ElmFeeder ), then the same MW and Mvar value is transferred from one feeder to the other.

A demand transfer is only possible if an active operation scenario (to record the changes) is available. The Apply all button will automatically apply all transfers that are stored in the current folder and which fit into the current study time. Before execution, the user is asked if the current network state should be saved in a new operation scenario. The same demand transfers can be applied as many times as desired during the validity period. If a non-zero power transfer has been executed and the source’s power is less than zero, a warning is printed to the output window indicating that the power limit has been exceeded. The applied transfers can be reverted by using the Reset all button. When the current operation scenario is deactivated, all load transfers executed while the operation scenario was active will be reverted. For information about operation scenarios please refer to Chapter 14 (Operation Scenarios).

12.3.3

Fault Cases and Fault Groups

This section discusses the data structure of the Faults folder, and the objects contained within it. The functionality of Event objects is described in Section 26.6: Events (IntEvt). The Faults folder

stores two types of subfolders:

1. Fault Cases folders which in turn store objects that represent Simulation Events . Simulation Events may contain a number of individual Events (Evt* ), e.g. short-circuits events, switching events. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 12. PROJECT LIBRARY 2. Fault Groups folders store Fault Groups (IntFaultgrp) objects, which in-turn reference fault Cases (Simulation Events or individual Events). The uppermost window in Figure 12.3.1 show an example project Faults folder. Two Fault Cases subfolders (“Cases North" and “Cases South"), and a Fault Groups subfolder Grouping Faults have been defined. The center window in Figure 12.3.1 shows the content of “Cases South", which stores three fault cases, “Bus 1", “G1", and “T1". In the lower window of Figure 12.3.1, a Fault Group named Fault Group has been defined inside the Grouping Faults folder, and contains a reference to the fault case “Line2-Line5" (which has previously been defined in the folder “Cases North"). Note: The use of IntEvt objects extends beyond PowerFactory ’s reliability analysis functions. Time domain simulations (EMT/RMS) make reference to IntEvt objects, in order to include simulation events which take place during a time-domain simulation. In this case the execution time sequence of the events must be defined. In the case of fault representations in the Operational Library by means of fault cases, only short-circuit and switching events are relevant.

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Figure 12.3.1: The Faults Folder DIgSILENT PowerFactory 15, User Manual

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CHAPTER 12. PROJECT LIBRARY Note that the calculation commands provided by the reliability assessment function of PowerFactory use Contingencies objects (ComContingency and ComOutage) to simulate the outage (and subsequent recovery) of one or more system elements. To avoid duplication of data, these objects can refer to previously defined Simulation Events (IntEvt). For information regarding the functionality of fault cases and fault groups in contingency analysis tools refer to Chapter 29 (Contingency Analysis). For the use of fault cases to create outages for the contingency analysis tools please refer to Chapter 30 (Reliability Assessment). The following sections provide a details of how to define Fault Cases and Fault Groups. Fault Cases A fault case can represent a fault in more than one component, with more than one event defined. For example, the fault case “Line 2-Line 5" shown in Figure 12.3.1 represents a short-circuit fault in transmission lines Line2 and Line5, i.e. the fault case “Line 2-Line 5" consists of short-circuit events for both components. There are two types of Fault Cases: 1. Fault cases without switch events (Type 1): Independent of the current topology and only stores the fault locations. The corresponding switch events are automatically generated by the contingency analysis tools. For further information refer to Chapter 30 (Reliability Assessment). 2. Fault Case with at least one switch event (Type 2): A Fault Case of Type 2 predefines the switch events that will be used to clear the fault. No automatic generation of switch events will take place. For further information please refer to Chapter 30 (Reliability Assessment). To create new Fault Cases or new Fault Groups folders, open the Faults project folder from the Operational Library and use the New Object icon (select Fault Cases(IntFltcases) or Fault Groups (IntFltgroups) respectively). To create new fault case (object of class IntEvt): 1. Multi-select the target components on a single line diagram. 2. Right-click and select Define → Fault Cases from the context-sensitive menu. 3. Select from the following options: • Single Fault Case: This creates a single simultaneous fault case including all selected elements. A dialogue box containing the created fault case is opened to allow the user to specify a name for the fault case. Press Ok to close the dialogue and saves the new fault case. • Multi fault Cases, n-1: This creates an n-1 fault case for each selected component. Therefore the number of fault cases created is equal to the number of components selected. This menu entry is only active if more than one component is selected. The fault case is automatically created in the database after selection. • Multi fault Cases, n-2: This creates an n-2 fault case for each unique pair among the selected components. Therefore the number of fault cases is (𝑏 · (𝑏 − 1)/2) where ”b” is equal to the number of selected components. This menu entry is only active if more than one component is selected. If only one component is selected, then no fault case will be created. The fault case is automatically created in the database after selection. • Mutually Coupled Lines/Cables, n-k : This creates fault cases considering the simultaneous outage of each coupled line in the selection. The fault cases created will consist of short-circuit events applied to the selected components. All breakers (except for circuit breakers, which are used to model a circuit breaker failure) will be ignored. • If only breakers are included in the selection, an error message will be issued. 176

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12.3. OPERATIONAL LIBRARY • If a simple switch (not a circuit breaker) is included in the selection, a warning message will be issued that this switch will be ignored. • If a circuit breaker is contained in the selection, then an Info message will be issued, that the CB will be used for modelling a CB failure and will not be handled as a fault location. Note: In the case that a branch is selected, the short-circuit event is generated for a (non-switch device with more than one connection) component of the branch. The component used in the event is: “Connection 1" if suitable, otherwise “Connection 2" if suitable, otherwise a suitable random component of the branch (line, transformer . . . ).

Fault Groups New Fault Groups are created in the data manager as follows: 1. Open the target Fault Groups folder and select the New Object icon

.

2. In the edit dialogue, specify the name of the Fault Group, and Add Cases (IntEvt) to the Fault Group.

12.3.4

Capability Curves (Mvar Limit Curves) for Generators

Reactive Power operating limits can be specified in PowerFactory through definition of Capability Curves (IntQlim). They are stored in Operational Library, within the Mvar Limit Curves folder . Synchronous generators (ElmSym) and static generators (ElmGenstat) defined in the Network Model can use a pointer to a Capability Curve object from the Load Flow page of their edit dialogue. When executing a Load Flow (with Consider Reactive Power Limits selected on the Basic Options page) generator Reactive Power dispatch will be limited to within the extends of the defined capability curve. For information about the dispatch of synchronous generators, refer to the synchronous machine technical reference in the appendix C (Synchronous Machine (ElmSym)). For information about Load Flow calculations and reactive power limits, refer to Chapter 21 (Load Flow Analysis). Note: If ’Consider Active Power Limits’ is selected on the Active Power Control page of the Load Flow command, Active power is limited to the lesser of the Max. Operational Limit and the Max. Active Power Rating specified on the Synchronous Machine Load Flow page.

Defining Capability Curves To define a new generator Capability Curve: 1. Open the folder Mvar Limit Curves 2. Click on the New Object icon will be displayed.

from the Operational Library.

and select Capability Curve. The new capability curve dialogue

3. Enter data points to define the generation limits, and Append Rows to add the required number of rows to the table. 4. To apply a Capability Curve to a generator: • Locate the Reactive Power Limit section on the Load Flow page of the synchronous machine’s or static generator’s dialogue. • Press

next to Capability Curve.

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CHAPTER 12. PROJECT LIBRARY • Choose Select and then select the required curve in the Mvar Limit Curves folder of the Operational Library (the required curve can also be created at this step by selecting the New Object icon . 5. Select a capability curve and press OK. Capability curves are included in operation scenario subsets; meaning that if a capability curve is selected/reset from a generator when an operation scenario is active, the change will be stored in the operation scenario. Once the operation scenario is deactivated, the assignment/reset of the curve is reverted. For information on working with operation scenarios, please refer to Chapter 14 (Operation Scenarios). To enter a capability curve for information purposes only (i.e. a capability curve which is not to be considered by the calculation), enter it on the Advanced tab of the Load Flow page. Then select User defined Capability Curve and enter the curve as a series of points in the table. Right-click on the rows to append, delete or insert new rows. Defining a Variation of a Capability Curve Similar to circuit breaker ratings (see Section 12.3.1 (Circuit Breaker Ratings), Capability Curves can become time-dependant by means of variations and expansion stages stored inside the Mvar Limit Curves folder. To create a time-dependent variation for a Capability Curve, navigate to theMvar Limit Curves folder in the left pane of a data manager window. Right-click on the folder and select New → Variation. Name the variation, press OK, name the Expansion Stage, and press OK. Changes to Capability Curves are recorded in the active expansion stage. To activate a variation of a Capability Curve, open the data manager. Right-click the Variation object in the Mvar Limit Curves folder and select Activate. For general information about variations and expansion stages please refer to Chapter 15(Network Variations and Expansion Stages).

12.3.5

Planned Outages

A Planned Outage is an object used to check and/or apply an Outage of Element or Generator Derating over a specified time period. Planned Outages are stored within the Operational Library in the Outages folder. • For the Outage of Element type, PowerFactory automatically isolates the referenced components. The switches connecting the target elements with the other network components are open and the terminals connected to the elements are earthed (if the Earthed option in the terminal (ElmTerm) dialogue is checked). Note that the target element can only be earthed if it is directly connected (without switches in the cubicle) to terminals, which are then connected through switches to the network terminals. • For a Generator Derating, a reference to the generator which is to be derated and the magnitude of the MW reductions is specified. For the Generator Derating, the maximum active power that can be dispatched (defined on the Load Flow page of the generator element dialogue, in the section Operational Limits) is recalculated as the difference between the maximum active power (section Active Power: Ratings) and the MW reductions. Note: If a Planned Outage object is defined in the Outages folder of the Operational Library, only the outage types Outage of Element and Generator Derating are enabled. Similarly if outage objects are defined in the Demand transfer folder, only the outage type Demand Transfer is enabled.

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12.3. OPERATIONAL LIBRARY Defining Outages and Deratings To create a new Element Outage or Generator Derating: 1. In the data manager, open the Outages folder. 2. Click on the New Object icon

, select Planned Outage and press Ok.

3. The Planned Outage dialogue will be displayed. In the Outage Type frame of the dialogue, the options Outage of an Element and Generator Derating will be enabled. Set the desired Outage Type, Start Time and End Time. 4. The definition of a Planned Outage requires reference(s) to relevant network components. To create a reference: • Press the Contents button of the outage object. • In the data browser that is displayed, create a reference to the target element by selecting the New Object icon (IntRef ). button in the Reference field to select the target element. • Press the • Press Ok to add the reference. 5. (Generator Derating only) Specify the MW Reduction (see previous section for details) for the generator derating. 6. To apply the Planned Outage, press the Apply button (the Apply button is only available if the study time lies within the outage period, and an Operation Scenario is active). Applied outages and generator deratings can be reset using the Reset button. Checking Outages and Deratings The Check All button in the Planned Outage dialogue is used to verify if the actions defined for the target element(s) have been performed (right-click a Planned Outage and select Check to perform an individual check). Only the outages within a valid period are considered. Outages marked as Out of Service are not regarded (even if the study time lies within the outage period). For an Outage of Element, the energizing state is always determined by a connectivity analysis. Any component that is connected to an External Grid or a reference Generator is considered to be energized. All other components are considered to be deenergized (if circuit breakers are open). A deenergized component is earthed if a topological connection to a grounding switch or an earthed terminal exists (terminal with the Earthed option checked). Note: If the outaged element is a branch element (ElmBranch), all contained elements are checked. If any of these elements is not correctly outaged, the whole branch is reported as not correctly outaged.

The fulfilment of programmed outages can also be checked via the use of the color representation function available within the single line graphic by setting the Colouring option to Outage Check from the color representation dialogue . The following states are colored, according to user preferences: • Components that are energized, but should be outaged. • Components that are deenergized and not earthed, but should be outaged. • Components that are deenergized and earthed, but should NOT be outaged. • Components that are deenergized, not earthed and should be outaged. • Generators that are not derated, but should be outaged. • Generators that are derated, but should NOT be outaged. DIgSILENT PowerFactory 15, User Manual

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12.3.6

Running Arrangements

store operational data (switch status) for a single substation. As Running Arrangement objects shown in Figure 12.3.2, a Running Arrangement uses a reference to the substation object (ElmSubstat) whose switch statuses are stored. A Start Time and End Time is used to specify the validity period of the Running Arrangement. Running arrangements are stored in the Running Arrangements folder in the Operational Library .

Figure 12.3.2: RA object dialogue

Different configurations of the same substation can be defined by storing the corresponding switch statuses in Running Arrangements. Different Running Arrangements can then be easily selected during a study. If a running arrangement is selected for a substation, the status of the substation switches cannot be modified (i.e. they become read-only). If there is no setting for a switch in a Running Arrangement (i.e. the Running Arrangement is incomplete), the switch will remain unchanged but its status will also be set to read-only. If the current Running Arrangement is deselected, switch status will be reverted to the status prior to application of the Running Arrangement, and write-access will be re-enabled. Running arrangements are defined and selected in the substation object dialogue Basic Data page. Note: Running arrangements store only the status of switches of class ElmCoup. The status of switches which are automatically created in a cubicle following the connection of a branch element (StaSwitch objects) are not considered in a running arrangement.

Further details of how to create, select, apply, and assign Running Arrangements are provided in the following sections. Creating a Running Arrangement To store the current status of the switches in a substation, a Running Arrangement object must be created. To create and save a new Running Arrangement (RA): 1. Click on an empty place in the substation graphic, and from the context-sensitive menu choose Edit Substation. Open the substation dialogue. 2. Click Save as (see Figure 12.3.3) to store the switch settings of the substation as a new RA. This button is only available if there is currently no RA selection active. 180

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12.3. OPERATIONAL LIBRARY 3. In the new RA dialogue is displayed, specify a name and time period, and press Ok. The new RA is automatically stored in the Running Arrangements folder in the Operational Library. An Overwrite button is available in the substation dialogue (if no RA is selected), to store current switch statuses to an existing RA.

Figure 12.3.3: Running Arrangement in a Substation Dialogue

Selecting a Running Arrangement A Running Arrangement (RA) can be selected in the Basic Data page of a substation dialogue (see Figure 12.3.3): 1. Open the substation dialogue. 2. In the Running Arrangement frame of the Substation dialogue, select defined RA’s.

from a list of previously

3. Select the desired RA. This selection is immediately reflected in the substation graphic. While an RA is selected, the switch statuses of a substation are determined by this RA and cannot be changed by the user (i.e. they are read-only). If there is no setting for a switch in an RA (i.e. the RA is incomplete), such a switch will remain unchanged but its status is also set to read-only. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 12. PROJECT LIBRARY Furthermore, there is a button Select by Study Time (also available via the context-sensitive menu when right-clicking on the data manager), which selects a valid RA automatically according to the study time. If there are multiple RAs valid for the current study time, or if there is no valid one, a warning is printed to PowerFactory ’s output window (nothing is selected in this case). Applying and Resetting a Running Arrangement An active Running Arrangement (RA) can be applied to a substation by pressing the Apply and Reset button from within the substation dialogue. This action copies the statuses stored in the RA directly in the substation switches. It is only available only if an RA is selected. The RA will be deselected afterwards. An RA can be directly set as the substation’s selected RA, using the Assign button (from within the RA dialogue). The following functional aspects must be regarded when working with running arrangements: • An RA can be selected for each substation. If an operation scenario is active, the selection of an RA in a substation is recorded in the operation scenario (i.e. the RA selection is part of the operational data included in the operation scenario subset). • If a variation is active (and there is no active operation scenario), the selection of the RA is stored in the recording expansion stage. • While an RA is selected, the switch statuses of the corresponding substation are determined by the RA and can not be modified. Any attempt to change such a switch status will be rejected and a warning message will be printed to the output window. The switch statuses preceding the activation of an RA remain unchanged and are restored when deselecting the RA. • The switch statuses stored in the RA could be incomplete due to the activation of a variation or a modification made to the network model. For example, if an RA was defined and then deactivated, and then later new switches were added to a substation. In this case if the RA is re-activated, a warning would be printed to the output window and the current switch statuses, which depend on the base network, active variations and active operation scenario, remain unchanged. Missing switch statuses will be added only when performing the Save as or Overwrite functions (available in the substation dialogue). • Switch statuses stored in the RA, and which are currently not required (depending on expansion stages) are ignored and remain unchanged. In this case a summary warning is printed during the RA activation. • It is not possible to add a new switch to a substation while a running arrangement is selected. Additionally, it is not possible to delete an existing switch from this substation. In both cases the action is blocked and an error message is issued. For information regarding operation scenarios and their application refer to Chapter 14 (Operation Scenarios). Assigning a Running Arrangement The Assign button contained in the Running Arrangement (RA) dialogue facilitates the selection of the RA as the one currently selected for the corresponding substation. This action is also available in the context-sensitive menu in the data manager (when right-clicking on an RA inside the data manager). It should be noted that assignment is executed immediately and cannot be undone by pressing the cancel button of the dialogue.

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Figure 12.3.4: Running Arrangement Dialogue

12.3.7

Thermal Ratings

Thermal Ratings objects (IntThrating) allow the definition of post-fault operational ratings for certain branch elements, depending on the fault duration and the loading prior to the fault. Thermal Ratings . They are two-dimensional objects are stored in the Thermal Ratings folder in the Operational Library matrices, with cells that contain the "short time" post-fault ratings (in MVA), according to the pre-fault loading (defined in the first column) and the duration of the fault/overloading (defined in the first row). References to Thermal Ratings are defined on the Basic Data page of the dialogue of the target branch elements. Elements that can use references to Thermal Ratings are: • Transmission lines (ElmLne). • 2- and 3-winding transformers (ElmTr2) and (ElmTr3). • Series reactors (ElmSind). • Series capacitors (ElmScap). Note that the rating table given on the Ratings page of the Thermal Rating object (when option Consider short term ratings is enabled) is used solely for the contingency analysis command in PowerFactory. In this calculation, the pre-fault loading conditions of the network components are determined after a base load flow calculation. The contingency analysis is then performed using a load flow command, where the post-contingency duration is specified. To create a new Thermal Ratings object: 1. Open the folder Thermal Ratings from the Operational Library. 2. Click on the New Object icon

and select Thermal Ratings.

3. The new object dialogue is displayed. To configure the table for the short-term ratings (only visible if the option Consider short term ratings is checked), go to the Configuration page and: • Introduce the increasing values for the pre-fault loading axis (Prefault %). By default, values between 0% and 80%, with increments of 5%, up to 84% are set. • Introduce the fault duration in minutes. Default values are: 360min, 20min, 10min, 5min, 3 min). The pre-fault continuous rating (used as the base to calculate the loading before the fault) and the postfault continuous rating (assumed as the branch element post-fault rating if the fault duration is larger than the largest duration time defined in the table) are defined on the Ratings page. The values of a thermal rating object can be edited at any time by double-clicking on it to open the Thermal Ratings dialogue. Similar to Circuit Breaker Ratings and Capability Curves, Thermal Ratings DIgSILENT PowerFactory 15, User Manual

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CHAPTER 12. PROJECT LIBRARY objects can be made to be time-dependant by means of variations and expansion stages stored inside the Thermal Ratings folder (refer to the Circuit Breaker Ratings section for an explanation on how to define time-dependant operational objects). When a contingency analysis (ComSimoutage) is configured, the user can define a post-contingency time. According to the pre-fault loading found by the load flow used to calculate the base case, and the post-contingency time (if specified), the ratings to be used in the contingency load flow are determined (based on the referred Thermal Ratings object). The loading of the branch elements after the contingency load flow are calculated with respect to the new ratings. For information about contingency analysis refer to Chapter 29 (Contingency Analysis).

12.4

Templates Library

The Templates folder is used to store and organize templates of network components (or groups of components) for re-use in a power system model. Components from templates are created using the graphical editor. Five kinds of templates are supported in PowerFactory : 1. Element template for single network elements: New single network elements with the same parameters as the original element are created. 2. Group template for non-composite graphic objects: New groups of objects (including graphical attributes) are created. 3. Substation template (composite node): New substations with the same configuration as the original substation (including its diagram). 4. Secondary Substation template: New secondary substations. 5. Branch template (composite branch): New branches with the same configuration as the original branch (including its diagram). , in the Library. When a template for a single Templates are normally stored in the Templates folder network element is defined, a copy of the original element is automatically created in the Templates folder. New templates of substations and branches will copy the objects together with all of their contents (including the diagram) to the Templates folder. New templates for groups of objects will copy the corresponding objects, together with their graphical information to a subfolder for groups of class IntTemplate within the Templates Library. For further information about working with templates, please refer to Section 9.2 (Defining Network Models with the Graphical Editor). Substation (composite node) templates ( or ), secondary substation ( ), busbar templates ( ), branch templates ( ), and general templates ( ) can be selected from the Drawing Toolbox on the right-hand pane of the PowerFactory GUI. To apply an element template: • Select the symbol for a substation, secondary substation, busbar, branch, or general template as required. • Select the required template. • Insert the new element in the single line graphic. Note: The use of Substation templates is recommended for diagrams of networks, where components are grouped in branches and substations. In this case the composite nodes can be graphically connected with the composite branch, forming an overview diagram of the complete network.

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12.4.1

General Templates

Any kind of single network component (lines, transformers, terminals, etc.) can be used to define an "Element" template; this is done by right clicking the desired element on a single line graphic and selecting Define Template from the context sensitive menu, a dialogue where the name of the new template is to be written pops up. After the name is given and the Ok button is pressed, a copy of the selected element is stored in the templates folder. Similarly, a group of network components can be ´ used to define a "Group" template, which will create a Stemplate’ folder ( ) storing the objects from the group together with their graphical information. If a group of elements containing substation and branches has been selected the elements outside the substation will not be added to the template.

12.4.2

Substation Templates

Existing substations can be used as "models" to define templates, which may be used later to create new substations. A new substation template is created by right clicking on one of the busbars of the detailed substation single line diagram and selecting Define substation template from the context sensitive menu. This action will copy the substation together with all of its contents (including its diagram even if it is not stored within this substation) in the Templates folder. Note: In case of creating templates which contain graphical information the default settings of the names and result boxes defining their graphical representation (font, frame, size,...) are copied into the template diagram so that they appear as in the source object(s).

12.4.3

Busbar Templates

Similar to creating substation templates, existing busbars can be used as a "models" to create userdefined templates, which may be used later to create new busbars. A new busbar template is created ´ by right clicking on the detailed single line diagram or simplified diagram of busbar and selecting SDefine substation template’ from the context sensitive menu. This action will copy the busbar together with all of its contents (including detailed and simplified diagrams) in the Templates folder. If the detailed busbar configuration has been modified, it is possible to right-click the (existing) simplified representation in the ´ main single line diagram and select SUpdate representation’. Busbars that have been created by the user in this way can be added to the single line diagram by ´ selecting the SGeneral Busbar System’ icon ( ). Note that for a busbar to be accessible from this icon, both detailed and simplified diagrams must be included within the busbar template, as in the previously described method.

12.4.4

Composite Branch Templates

Composite Branch templates can be defined as follow 1. To create a Branch template, navigate to the Library → Templates folder in the Data Manager. 2. Right-click on the right pane of the Data Manager and select New → Branch from the context sensitive menu. 3. In the branch edit dialogue, define the name of the branch and press Ok. 4. A new (empty) single line diagram will be displayed. Draw the required elements (for example, a terminal with two lines connected, with each line connected at one end only).

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CHAPTER 12. PROJECT LIBRARY 5. To create an instance of the Branch from the newly created Branch template, navigate back to the main grid diagram, then select the Composite Branch ( ) icon and connect the branch to existing terminals on the Single Line Diagram. Alternatively, composite branches can be defined in the Data Manager as described in Chapter 10: Data Manager, Section 10.3.4 (Defining Composite Branches in the Data Manager).

12.4.5

Example Generator Template

Consider the following example, where there is a power station with multiple transformers, generators, and control systems of the same type. The model can be created using templates as follows: 1. Firstly, define type data for the transformer, generator, and control system. 2. Add a single instance of the generating unit (including generator transformer) to the network model. 3. Define a Template by selecting the generator, generator bus, and transformer, then right-click and select Define Template. Optionally include the control system model with the template. 4. To create another instance of the newly created template, select the General Templates icon ( and place it on the single line graphic.

12.4.6

)

Example Busbar Template

Consider the following example where there is network with multiple instances of a Double Busbar System. However, the Double Busbar System required for this particular model is a variant on the standard Double Busbar System, which requires two switches. To simplify the task of developing the model, a Template may be defined as follows: 1. Place a standard Double Busbar System on the single line graphic. 2. Right-click and select Show Detailed Graphic of Substation. 3. Extend the busbar length, and then copy and duplicate the switches connecting "BB1" to "BB2" (see Figure 12.4.1).

Figure 12.4.1: Detailed Busbar Layout 4. On the main Grid single line graphic, select Draw Existing Net Elements, press the Logical Switch icon ( ) and draw the second switch connecting "BB1" to "BB2". 186

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12.4. TEMPLATES LIBRARY 5. Right-click either busbar in the overview diagram and select Define Substation Template (see Figure 12.4.2), then name the Template.

Figure 12.4.2: Example Busbar Template 6. Use the General Busbar System icon ( the power system model.

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Chapter 13

Grouping Objects This chapter describes the management and functionality of the objects used to group network components.

13.1

Areas

To facilitate the visualization and analysis of a power system, elements may be allocated into areas (ElmArea ). The single line graphics can then be colored according to these areas and special reports after load flow calculations (’Area summary report’ and ’Area interchange report’) can be generated. Area objects are stored inside the Areas folder ( ) in the Network Data directory. To define a new area: • Multi select the components belonging to the new area (in the Data Manager or in a single line diagram). • Right click on the selection and select Define → Area from the context sensitive menu. • After the area has been defined, terminals can be added to it by selecting Add to. . . → Area. . . in their context sensitive menu. In the edit dialogue of the new area you must select a colour to represent the area in the single line diagrams. Using the Edit Elements button you can have access to all the element belonging to that area in a data browser, then you can edit them. The Mark in Graphic button may be used to locate the components of an Area in a single line diagram. Note: Areas that are created/deleted when a recording expansion stage is active; become available/not available only if the corresponding variation is active and the expansion stage activation time is earlier than the current study time.

For information concerning the visualization of areas within the single line Graphic please refer to Chapter 9: Network Graphics, subsection 9.7.6 (Graphic Attributes and Options). For information about reporting Area results please refer to Chapter 17 (Reporting and Visualizing Results).

13.2

Virtual Power Plants

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CHAPTER 13. GROUPING OBJECTS Virtual Power Plants are used to group generators in the network, in such a way that the total dispatched active power is set to a target value. The dispatch of each generator (the Active Power field available in the Dispatch section of the Load Flow tab in the generator element dialogue) is scaled according to the Virtual Power Plant rules (must run, merit of order, etc.), in order to achieve the total target value. Virtual Power Plant objects (ElmBmu the Network Data directory.

13.2.1

) are stored inside the Virtual Power Plants folder (

) within

Defining and Editing a New Virtual Power Plant

A new Virtual Power Plant is created by: • Multi selecting in a single line diagram or in a data browser an initial set of generators to be included in the Virtual Power Plant; • Then pressing the right mouse button and selecting Define → Virtual Power Plant from the context sensitive menu.

Figure 13.2.1: Defining a Virtual Power Plant

Alternatively you can create a new empty Virtual Power Plant by using the Data Manager: • Open a data manager. • Find the Virtual Power Plant folder (

) and click on it.

• Press the icon for defining new objects (

).

• select Others. • Then select Virtual Power Plant (ElmBmu) in the list box. • Assign a suitable name to the Virtual Power Plant. • Press OK. The rules which determine the dispatch of the selected generators are set in the Virtual Power Plant dialogue. The total active power to be dispatched is set in the field ’Active Power’. The dispatch of the 190

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13.2. VIRTUAL POWER PLANTS belonging generators (variable “pgini" from the Load Flow tab of the generator) is set by pressing the Apply button. If the ’Maximal active power sum’ of the included generators (sum of the maximal active power operational limit of the generators) is smaller than the active power to be dispatched, an error message pops up. Otherwise the dispatch is set according the user defined ’Distribution Mode’: According to merit order Distribution of the dispatched active power is done according to the priorities given to each generator in the Merit Order column of the ’Machines’ table (this value can also be set in the Optimization tab of the generators dialogue). Lower values have higher priority. Generators with the option ’Must Run’ checked are dispatched even if they have low priority (high value). It is assumed that the merit of order of all generators in the Virtual Power Plant is different. If not an error message appears after the ’Apply’ button is pressed. According to script The rules for the dispatch are set in user defined DPL scripts, which are stored inside Virtual Power Plant object. To create new scripts or to edit the existing ones you must open a data browser with the ’Scripts’ button. Note: The Virtual Power Plant active power is part of the operation scenario subsets and therefore is stored in the active operation scenario (if available). The active power is stored in the active expansion stage (if available) if no active operation scenario is active. Virtual Power Plants that are created/deleted when a recording expansion stage is active; become available/non available only if the corresponding variation is active and the expansion stage activation time is earlier than the current study time.

13.2.2

Applying a Virtual Power Plant

Check that the active power set for the Virtual Power Plant is less than or equal to the maximum power. Press the Apply button.

13.2.3

Inserting a Generator into a Virtual Power Plant and Defining its Virtual Power Plant Properties

Generators are added to an existing Virtual Power Plant by adding a reference in the ’Optimization’ tab of their edit dialogue. Notice that a generator can belong to at most one Virtual Power Plant. Define the Merit Order and must run properties as required. You also can add a generator to a Virtual Power Plant by clicking with the right mouse button on the element in the network graphic and choose Add to. . . → Virtual Power Plant. . . from the context sensitive menu.

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Figure 13.2.2: Virtual Power Plant

13.3

Boundaries

Boundaries are used in the definition of network reductions and to report the interchange of active and reactive power after a load flow calculation. Boundary objects (ElmBoundary ) may define topological regions by specifying a topological cut through the network. New boundaries are created by specifying the cubicles that define the cut through the network. The cubicles in the boundary element define a cut through the network, that together with the orientations are used to define the corresponding "Interior Region". Topologically, the interior region is found searching through the network starting at each selected cubicles towards the given direction. The topological search continues until either an open switch or a cubicle that is part of the boundary list is found. Any open switch that is found by this search is considered to be part of the interior region. To define a new Boundary: • Multi select a set of cubicles and terminals in the single line diagram, which will define the boundary. For doing this: freeze (!) the network diagram and click on the corresponding ends of lines, transformers etc., and on one busbar to define the orientation of the boundary. • Then click with the right mouse button on the selection. • Choose in the context sensitive menu Define. . . → Boundary. . . . The dialogue of the new Boundary will pop up. 192

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13.4. CIRCUITS (ELMCIRCUIT) • By pressing OK the new Boundary object is created in the Boundaries folder of the Network Model. To add cubicles to an existing Boundary: • In the Boundary dialogue, right click on the table (on the number of a row) that lists the included cubicles. • Select Insert rows, Append rows or Append n rows from the context sensitive menu. • Double click on the Boundary Points cell of the new line. • Select the target cubicle using the data browser that pops up. After selecting the desired cubicle, the terminal and the branch element connected to it are added to the ’Terminal’ and ’Components’ cells on the table. By default the ’Orientation’ (direction used to determine the interior region) is set to the branch; you can change it in order to direct the definition of the internal region to the connected terminal. Cubicles can be retired from a Boundary by selecting ’Delete rows’ from the context sensitive menu of the table in the element dialogue. The selected colour at the bottom of the dialogue is used to represent the boundary in the single line diagrams ( ). Each element in the graphic is colored according to the following criteria: • If it uniquely belongs to one interior region of a boundary to be drawn, its colour will be assigned to that specific boundary colour. • If it belongs to exactly two of the interior regions of the boundaries to be drawn, its will be represented with dashed lines in the specific boundary colours. • If it belongs to exactly more than two of the interior regions of the boundaries to be drawn, its will be represented with dashed lines in black and the colour selected for multiple intersections. The Edit Interior Elements button can be used to list in a data browser all the components included in the internal region. The Mark Interior Region button marks all the components of the interior region in the selected network diagram. Topological changes in the network that affect the defined interior regions are automatically detected by the program. Note: Boundaries that are created or deleted when a recording expansion stage is active; become available/not available only if the corresponding variation is active and the expansion stage activation time is earlier than the current study time.

13.4

Circuits (ElmCircuit)

Circuits are objects of class ElmCircuit ( ), and are used to group branches in order to clarify which branches are connected galvanically. Each branch (ElmBranch) can have a reference to any defined circuit object. This feature allows branches to be sorted according to the circuit to which they belong. To create a new Circuit: • In the Data Manager open the Circuits folder from the Network Model. • Click on the New Object icon. • The edit dialogue of the new Circuit pops up. Give a name to the new object and press Ok. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 13. GROUPING OBJECTS Branches are added to a circuit using the pointer from the ’Circuit’ field of the branch dialogue. The button Branches in the Circuit dialogue opens a data browser listing the branches that refer to that circuit. Note: Circuits that are created or deleted when a recording expansion stage is active; become available/not available only if the corresponding variation is active and the expansion stage activation time is earlier than the current study time.

13.5

Feeders

When analyzing a system it is often useful to know where the various elements are receiving their power ). supply from. In PowerFactory this is achieved using Feeder Definitions (ElmFeeder A feeder is defined at a line or transformer end, and then the feeder definition algorithm searches the system from the definition point to determine the extent of the feeder. The feeder ends when: • An open breaker is encountered; or • The end of a line of supply is encountered; or • ’Terminate feeder at this point’ is enabled in a cubicle (optional); or • A higher voltage is encountered (optional). Once a feeder has been defined it may be used to scale the loads connected along it according to a measured current or power, to create voltage profile plots or to select particular branches and connected objects in the network. Following load flow calculations, special reports can be created for the defined feeders. To distinguish the different feeder definitions, they can be coloured uniquely in the single line graphic. All feeder objects are stored in the Feeders folder ( ) in the Network Data folder. A new feeder is created by right-clicking on a cubicle (that is, when the cursor is held just above the breaker in the single line diagram) and selecting Define → Feeder. . . . Once the option Feeder has been selected, the Feeder dialogue pops up. There you can define the desired options for the new object. After pressing Ok, the new Feeder is stored in the Feeders folder of the Network Model. Any existing Feeder can be edited using its dialogue (double click the target Feeder on a data browser). The Feeder dialogue presents the following fields: Name Cubicle Is a reference to the cubicle where the Feeder was created. It is automatically set by the program once the Feeder is created. Zone Reference to the Zone (if any) to which the feeder belongs. A Feeder is assigned to the zone of the local busbar/terminal. Color Sets the colour be used when the Feeder Definitions colouring mode ( the single line diagram.

) is engaged in

Terminate feeder whenEˇ A feeder will, by default, terminate when a higher voltage level is encountered, however, this may not always be desirous. This may be prevented by un-checking this option. The feeder will now continue ’past’ a higher voltage level and may be terminated at a user defined cubicle if desired. To manually terminate a feeder right-click a branch element above the breaker (to select the desired cubicle where the feeder is going to end) and select Edit Cubicle. The dialogue of the cubicle dialogue will be presented, and the ’Terminate feeder at this point’ option may be checked.

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13.5. FEEDERS Orientation The user may select the direction towards the feeder is defined. ’Branch’ means that the feeder starts at the cubicle and continues in the direction of the connected branch element. ’Busbar’ means that the Feeder is defined in the direction of the connected Terminal. Load Scaling In any system some loads values may be accurately known whilst others are estimated. It is likely that measurement points exist for feeders in the system as well, and thus the power that is drawn through this feeder is also known. The load scaling tool assists the user in adjusting these estimated load values by scaling them to match a known feeder power or current that has been measured in the real system. More information about the use of the Load Scaling Function is given below. Elements The Mark in Graphic button may be used to select all the elements of a Feeder in the desired single line diagram. The Edit button is used to list all the elements belonging to a Feeder in a data browser. To use the Load Scaling tool first define which loads may be scaled by enabling the ’Adjusted by Load Scaling’ option on the Load-Flow tab of the load dialogue. All of the loads in a feeder may also be quickly viewed by editing the feeder from the feeders folder. Load scaling is now performed by the load-flow calculation function when: • At least one feeder is defined with load scaling according to a current or power. • The option ’Feeder Load Scaling’ is enabled in the load-flow command dialogue (basic options). • At least one load exists in the feeder area for which – A change in operating point affects the load-flow at the feeder position – The option ’Adjusted by Load Scaling’ has been enabled. The load-flow calculation will then adjust the scaling of all adjustable loads in the feeder areas in such a way that the load-flow at the feeder equals the current or power set-point. The feeder setpoint is influenced by the zone scaling. This means that the current or power flow as calculated by the load-flow could differ from the setpoint in the feeder dialogue when the busbar where the feeder is defined is part of a zone. For instance, a feeder has a set-point of 1.22 MVA. The busbar is in a zone and the zone-scale is set to 0.50. The flow at the feeder position will thus be 0.61 MVA. For information about colouring the single line graphic according to feeder definitions please refer to Chapter 9: Network Graphics, Section 9.7.6 (Graphic Attributes and Options). For information about voltage profile plots, please refer to Chapter 17 (Reporting and Visualizing Results). Defining Feeders from a Terminal Element Often it is useful to be able to quickly setup a feeder or many feeders from a ’source’ bus within the system. There is a specific methodology within PowerFactory for this purpose. The procedure is as follows: 1. Right-click the target terminal where the feeder/s should be defined from. 2. Choose the option Define → Feeder. . . from the context sensitive menu that appears. This step is illustrated in Figure 13.5.1. 3. PowerFactory will automatically create Feeder objects for each of the connected two terminal elements, for example lines and transformers. The list of created feeders is displayed in a pop-up window. The default name for each feeder is the concatenation of the terminal name and the connected object. 4. Adjust the feeder colours and definitions as required and remove any unwanted feeders. DIgSILENT PowerFactory 15, User Manual

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Figure 13.5.1: Definition of Feeders from a terminal by right-clicking the terminal Note: The Load Scaling options are part of the operation scenario subsets; therefore they are stored in the active operation scenario (if available). The Load Scaling options are stored in the active expansion stage (if available) if no active operation scenario is active. feeders that are created or deleted when a recording expansion stage is active; become available/not available only if the corresponding Variation is active and the expansion stage activation time is earlier than the current study time.

13.6

Operators

For descriptive purposes, it is useful to sort network components according to their operators. Additionally, system operators may find it advantageous to generate summary reports of the losses, generation, load, etc. according to their designated region(s). PowerFactory allows the definition of operators, the assignment of network components to these operators, and the identification of operators on single line diagrams by means of Operator objects. The Operator objects (ElmOperator, ) are stored in the Operators folder ( ) in the Network Model directory. To create a new operator: • In the Data Manager open the Operators folder from the Network Model. • Click on the ’New Object’ icon. • The edit dialogue of the new operator pops up: – Give a name to the new object. – Select a colour to represent the operator se in the corresponding colouring mode of the single line diagram. – Press Ok. Network elements (class name Elm* ) such as terminals, switches, lines, generators, transformers, relays or composite models (ElmComp), Substations (ElmSubstat) and Branches (ElmBranch) can be assigned to an operator by means of the reference ’Operator’ from the Description tab of their dialogue. Note: Operators that are created or deleted when a recording expansion stage is active; become available/not available only if the corresponding variation is active and the expansion stage activation time is earlier than the current study time

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13.7. OWNERS

13.7

Owners

For descriptive purposes it is useful to sort network components according to their owners. Additionally, for network owners it may prove advantageous to generate summary reports of the losses, generation, load, etc. for their region(s). Similar to Operators, PowerFactory allows the definition of network owners, and the assignment of network components to them, by means of Owner objects. ) are stored in the ’Owners’ folder ( ) in the Network Model direcThe Owner objects (ElmOwner, tory. They are created following the same procedure described for operators. Network elements (class name Elm* ) such as terminals, switches, lines, generators, transformers, relays or composite models (ElmComp), Substations (ElmSubstat) and Branches (ElmBranch) can be assigned to an operator by means of the reference ’Operator’ from the Description tab of their dialogue. Note: Operators that are created or deleted when a recording expansion stage is active; become available/not available only if the corresponding variation is active and the expansion stage activation time is earlier than the current study time

13.8

Paths

A path (SetPath, ) is a set of two or more terminals and their interconnected objects. This is used primarily by the protection module to analyze the operation of protection devices within a network. The defined paths can be coloured in a single line graphic using the colouring function. New paths are stored inside the Paths folder ( ) in the Network Data directory. To create a new Path: • In a single line diagram select a chain of two or more terminals and their inter-connecting objects. • Right click on the selection. • Select the option Path → New from the context sensitive menu. • The dialogue of the new path pops up, give a name and select the desired colour for the corresponding colour representation mode in the single line diagram. The references to the objects defining the Path (First/Last Busbar First/Last Branch) are automatically created by the program, according to the selection. • After pressing Ok the new path is stored in the Paths folder of the Network Model. By using the Elements button of the Path dialogue you can have access to all the element belonging to the path in a data browser, there you can edit them. The Select button may be used to locate the components of the path in a single line diagram. With the Toggle button you can invert the order of the objects limiting the path (First/Last Busbar First/Last Branch). This order is relevant when evaluating directional protective devises. New objects can be added to a path by marking them in a single line diagram (including one end of the target path and a busbar as the new end) right clicking and selecting Path → Add to from the context sensitive menu. Objects can be removed from a Path (regarding that the end object of a Path must be always a busbar) by marking them in the single line diagram, right clicking and selecting Path → Remove Partly from the context sensitive menu. The Remove option of the Path context sensitive menu will remove the firstly found path definition of which at least one of the selected objects is a member. For information about the colouring function please refer to Chapter 9: Network Graphics, subsection 9.7.6 (Graphic Attributes and Options). For information about the use of the path definitions for the analysis of the protective devices, please refer to Chapter 39 (Protection). DIgSILENT PowerFactory 15, User Manual

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Note: Paths that are created or deleted when a recording expansion stage is active; become available/not available only if the corresponding variation is active and the expansion stage activation time is earlier than the current study time

13.9

Routes

Routes are objects which are used to group line couplings (tower elements). Each coupling (ElmTow) ). Each route has a color that can be used to can have a reference to any defined route (ElmRoute, identify it in single line diagrams, when the corresponding colouring function is enabled. For information regarding line couplings please refer to the technical reference for the transmission line model (See Appendix C: Technical References of Models, section C.1.5.1(Line ElmLne)).

13.10

Zones

) in order to represent geComponents of a network may be allocated to a zone object (ElmZone, ographical regions of the system. Each zone has a colour which can be used to identify the elements belonging to it in the single line graphic. These elements can be listed in a browser format for group editing; additionally all loads belonging to the zone can be quickly scaled from the zone edit dialogue. Reports for the defined zones can be generated following calculations. Upon being defined, zones are by default stored inside the Zones folder (

) in the Network Data folder.

Zones are created by multi-selecting elements, right-clicking and choosing Define → Zone. . . from the context sensitive menu. The option Add to → Zone. . . can be selected when a zone(s) have already been defined.

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Chapter 14

Operation Scenarios 14.1

Introduction

Operation Scenarios are used to store operational data such as generator dispatch, load demand, and network line/switch status. Individual Operation Scenarios are stored within the Operations Scenarios folder, and can be easily activated and deactivated. This Chapter describes PowerFactory operation scenarios. Note: Parameter Characteristics can also be used to modify network operational data - see Section 16.2 (Parameter Characteristics) for details.

14.2

Operation Scenarios Background

Operation Scenarios are used to store network component parameters that define the operational point of a system. Examples of operational data include generator power dispatch and a load demand. Operational data is typically distinguished from other component data because it changes frequently. Compare for instance, how often a generator changes its power set-point, with how often the impedance of the generator transformer changes. Storing recurrent operation points of a network and being able to activate or deactivate them when needed accelerates the analyses of the network under different operating conditions. PowerFactory can store complete operational states for a network in objects called operation scenarios (IntScenario, ). Operation scenarios are stored inside the operation scenarios folder ( ) in the project directory. You can define as many operation scenarios as needed; each operation scenario should represent a different operational point. Figure 14.2.1 shows a project containing three operation scenarios (Peak Load, Light Load and Shoulder Load) the content of the ’Peak Load’ scenario (its subsets) is shown in the right pane of the data manager.

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Figure 14.2.1: Operation Scenarios and operation scenariosŠ Subsets

A new operation scenario is defined by saving the current operational data of the active network components. Once they have been created, operation scenarios can be activated to load the corresponding operational data. If an operation scenario is active and certain operational data is changed, these changes are stored in the active operation scenario (if you decide to save the changes). If the current operation scenario is deactivated, the active network components revert to the operational data that they had before the activation of the operation scenario (this is the ’default’ operational data). Changes made to the ’default’ operational data do not affect data within existing operation scenarios. Operation scenario data stored within each operation scenario is separated into subsets, with one subset of operational data created for every grid in the network model. It is possible to ’exclude’ the operational data for individual grids. This prevents the operation scenario from saving the operational data for any subset where this option is active. For example, you might be working with a network model with four grids, say North, South, East and West. Perhaps you do not wish to store operational data for the ’West’ grid because the models in this grid have fixed output regardless of the operational state. By excluding the operational data subset for this grid, the default data can be used in all cases, even though the operational data is different in the other three grids. When working with active operation scenarios and active expansion stages, modifications on the operational data are stored in the operation scenario whereas the expansion stage keeps the default operational data and all other topological changes. If no operation scenarios are active and new components are added by the current expansion stage, the operational data of the new components will be added to the corresponding operation scenario when activated. Note: When an operation scenario is active, the operational data is distinguished in the network component dialogues because it is written using a blue font colour.

14.3

How to use Operation Scenarios

This sub-section explains how to complete the common tasks you will need when working with operation scenarios. The most common tasks are creating a new operation scenario, saving data to an operation scenario, Activating an existing operation scenario, Deactivating an operation scenario and identifying parameters stored within an operation scenario.

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14.3.1

How to create an Operation Scenario

There are two ways to create an operation scenario. Method 1 Follow these steps: 1. In the data manager, right-click on the operation scenarios folder in the active project. 2. Select New → Operation Scenario from the context-sensitive menu as shown in Figure 14.3.1. The dialogue of the new operation scenario pops up.

Figure 14.3.1: Creating a new operation scenario object using the data manager. 3. Enter the name for the operation scenario in the name field. 4. Press OK. The operation scenario will appear as a new object within the operation scenariosŠ folder. Method 2 Follow these steps: 1. From the main PowerFactory menu go to the File menu and select File → Save Operation Scenario as. . . (see Figure 14.3.2). The dialogue of the new operation scenario pops up.

Figure 14.3.2: Using the Main Menu to Save as a new operation scenario

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CHAPTER 14. OPERATION SCENARIOS 2. Enter the name for the operation scenario in the name field. 3. Press OK. The new operation scenario is created within the operation scenariosŠ project folder and automatically activated and saved.

14.3.2

How to save an Operation Scenario

Why do you need to save Operation Scenarios? Unlike all other PowerFactory data, changes to operational data are not automatically saved to the database if an operation scenario is active. So, after you update an operation scenario (by changing some operational data) you must save it. If you prefer automatic save behavior, you can activate an automatic save option setting - see Section 14.5.1. How to know if an Operation Scenario contains unsaved data If any operational data (of a network component) is changed when an operation scenario is active, the unsaved status of it is indicated by an asterisk (* ) next to the icon for the operation scenario as shown in Figure 14.3.3. The other situation that causes an operation scenario icon to appear with an asterisk is when new network components are added to the model. Any operational parameters from these models are not incorporated in the active operation scenario until it is saved.

Figure 14.3.3: An asterisk indicates unsaved changes in operation scenarios

Options to Save an Operation Scenario There are four ways to save a modified operation scenario to the database. They are: • The menu entry Save Operation Scenario in PowerFactory ’s main file menu. • The button Save in the dialogue window of the operation scenario. • The button Save Operation Scenario (

) in the main icon bar (see Figure 14.3.4).

Figure 14.3.4: The Save Operation Scenario Button in the Main Icon Bar • The context-sensitive menu (right mouse button) entry Action -> Save of the operation scenario (see Figure 14.3.5).

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14.3. HOW TO USE OPERATION SCENARIOS

Figure 14.3.5: Saving an operation scenario using the context-sensitive menu Note: The button Save as from the operation scenario dialogue (only available for active operation scenarios) can be used to save the current operational data as a new operation scenario. The new operation scenario is automatically activated upon being created.

14.3.3

How to activate an existing Operation Scenario

Switching between already available operation scenarios is a common task. There are two methods for activating an existing operation scenario. Method 1 Follow these steps: 1. Go to the operation scenarios’ folder within your project using the data manager. 2. Right-click the operation scenario that you wish to activate. The context sensitive menu will appear. 3. Choose the option Activate from the menu. If a currently active operation scenario contains unsaved data, you will be prompted to save or discard this information. Method 2 Follow these steps: 1. From the main file menu choose the option Activate Operation Scenario. A pop-up dialog will appear, showing you the available operation scenarios. 2. Select the operation scenario you wish to Activate and press OK. If a currently active operation scenario contains unsaved data, you will be prompted to save or discard this information. Note: The active operation scenario can be displayed in the status bar. To do this right-click the lower right of the status bar and choose display options → operation scenario.

14.3.4

How to deactivate an Operation Scenario

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CHAPTER 14. OPERATION SCENARIOS Method 1 Follow these steps: 1. Go to the operation scenariosŠ folder within your project using the data manager. 2. Right-click the operation scenario that you wish to deactivate. The context sensitive menu will appear. 3. Choose the option deactivate from the menu. If the operation scenario contains unsaved data, you will be prompted to save or discard this information. Method 2 From the main file menu choose the option Deactivate Operation Scenario. If the operation scenario contains unsaved data, you will be prompted to save or discard this information. Note: On deactivation of an operation scenario, previous operational data (the ’default’ operational data) is restored.

14.3.5

How to identify operational data parameters

Because the operation scenario only stores a subset of the network data, it is useful to know exactly what data is being stored by the operation scenario. This is relatively easy to see when you have an active scenario. Data that is stored in the operation scenario is highlighted with a blue font. This appears in both the object dialogues and the data manager browser as shown in Figures 14.3.6 and14.3.7.

Figure 14.3.6: Blue highlighted operational data in an element dialogue

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14.4. ADMINISTERING OPERATION SCENARIOS

Figure 14.3.7: Blue highlighted operational data in a browser window

14.4

Administering Operation Scenarios

In this sub-section the operation scenario administrative tasks are explained. This includes reporting operational scenario data status, comparing operation scenarios, viewing the non-default running arrangements, applying data from one operation scenario to another (copying), updating the base network model, excluding grids from the operation scenario and creating a time based operation scenario.

14.4.1

How to view objects missing from the Operation Scenario data

When you add a component to a network, the data is not automatically captured in the active operation scenario until you save the scenario. The operation scenario appears with an asterisk next to its name in the data manager. If you want to get a list of all the objects that have operational data that is missing from the active scenario, then you need to print the operation scenario report. To do this, follow these steps: 1. Open the active operation scenario dialog by finding the operation scenario in the data manager right-clicking it and selecting edit from context sensitive menu. 2. Press the Reporting button. A list of objects with data missing from the operation scenario is printed by PowerFactory to the output window. Note: If you double click a listed object in the output window the dialog box for that object will open directly allowing you to edit the object. You can also right click the name in the output window and use the function ’Mark in Graphic’ to find the object.

14.4.2

How to compare the data in two operation scenarios

It is sometimes useful to compare data in two separate operation scenarios so that key differences can be checked. To compare two operation scenarios: 1. Deactivate all operation scenarios that you wish to compare. Only inactive operation scenarios can be compared. 2. Open the first operation scenario dialog by finding the operation scenario in the data manager right-clicking it and selecting edit from context sensitive menu. 3. Press the Compare button. A data window browser will appear. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 14. OPERATION SCENARIOS 4. Choose the second operation scenario and press OK. A report of the operation scenario differences is printed by PowerFactory to the output window.

14.4.3

How to view the non-default Running Arrangements

Any running arrangements that are assigned to substations will be stored as part of the operational data. The operation scenario has a function that allows you to view any substations with active running arrangements that are different from the default running arrangement for that substation. The default running arrangement is determined by the running arrangement that is applied to the substation when no operation scenarios are active. To view all the non-default Running Arrangements follow these steps: 1. Open the active operation scenario dialog by finding the operation scenario in the data manager, right-clicking it and selecting edit from context sensitive menu. 2. Press the Reporting RA button. PowerFactory prints a report of the non-default Running Arrangements to the output window. Note: Most of these actions are also available in context-sensitive menu when right-clicking on an operation scenario (Action → . . . ).

14.4.4

How to transfer data from one Operation Scenario to another

As explained in the chapter introduction, within each operation scenario there is a subset of operation scenario data for each grid in the network model. Therefore, there are two options when transferring data from one operation scenario to another, either copying all the operation scenario data at once, or only copying a subset of data for an individual grid. Both methods are explained within this section. Transferring operational data from one grid only To transfer the operational data from a single grid subset to the same grid subset of another operation scenario follow these steps: 1. Activate the target operation scenario. 2. Right-click the source operation scenario subset. 3. From the context sensitive menu select Apply. A pop-up dialog will appear asking you if you really want to apply the selected operational data to the active operation scenario. 4. Click OK. The data is copied automatically by PowerFactory. Warning, any data saved in the equivalent subset in the active scenario will be overwritten. However, it will not be automatically saved. Transferring operational data from a complete operation scenario To transfer the operational data from a complete operation scenario to another operation scenario follow these steps: 1. Activate the target operation scenario. 2. Right-click the source operation scenario. 3. From the context sensitive menu select Apply. A pop-up dialog will appear asking you if you really want to apply the selected operational data to the active operation scenario. 4. Click OK. The data is copied automatically by PowerFactory. Warning, any data saved in the active scenario will be overwritten. However, it will not be automatically saved. 206

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14.4.5

How to update the default data with operation scenario data

As a user, sometimes you need to update the default operational data (the operational data parameters that exist in the network when no operation scenario is active) with operational data from an operation scenario within the project. To do this: 1. Deactivate any active operation scenario. 2. Right-click the operation scenario that you want to apply to the base model. 3. From the context sensitive menu select Apply. A pop-up dialog will appear asking you if you really want to apply the selected operational data to the base network data 4. Click OK. The data is copied automatically by PowerFactory. Warning, any data saved in the base network model will be overwritten.

14.4.6

How exclude a grid from the Operation Scenario data

Background By default, each operation scenario contains several subsets, one for each grid in the network model. For example, you might be working with a network model with four grids, say North, South, East and West. In such a case each operation scenario would contain four subsets. Now it might be the case that you do not wish to store operational data for the ’West’ grid because the models in this grid have fixed output etc. regardless of the operational state. By excluding the operational data subset for this grid, the default data can be used in all cases, even though the operational data is different in the other three grids. How to exclude a Grid from the Operation Scenario 1. Select an operation scenario using the data manager. 2. Double-click the subset of the grid that you wish to exclude (you can only see the subsets in the right panel of the data manager). A dialog for the subset should appear. 3. Check the ’Excluded’ option and the operational data from this grid will not be included within the operation scenario the next time it is saved.

14.4.7

How to create a time based Operation Scenario

Background By default, operation scenarios do not consider the concept of time. Therefore, when you activate a particular operation scenario, the operational parameters stored within this scenario are applied to network model regardless of the existing time point of the network model. However, sometimes it is useful to be able to assign a ’validity period’ for an operation scenario, such that if the model time is outside of the validity period, then the changes stored within the operation scenario will be ignored and the network model will revert to the default parameters. The concept of validity periods can be enabled in PowerFactory by using the Scenario Scheduler. There are two tasks required to use a ’Scenario Scheduler’. Firstly, it must be created, and secondly it must be activated. These tasks are explained below. How to create a Scenario Scheduler To create a Scenario Scheduler follow these steps:

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CHAPTER 14. OPERATION SCENARIOS 1. Go to the operation scenarios’ folder within your project using the data manager. 2. Click the New Object icon

. A object selection window will appear.

3. From the Element drop down menu choose the ’Scenario Scheduler’ (IntScensched). 4. Press OK. The scenario scheduler object dialogue will appear as shown in Figure 14.4.1. Give the scheduler a name.

Figure 14.4.1: The Scenario Scheduler (IntScensched) dialogue 5. Double-click on the first cell within the operation scenario. A scenario selection dialogue will appear. 6. Choose an operation scenario to schedule. 7. Adjust the start time of the schedule by double clicking the cell within the Start Time column. 8. Adjust the end time of the schedule by double clicking the cell within the End Time column. 9. Optional: To add more scenarios to the scheduler, right-click an empty area of the scheduler and Append Rows. Repeat steps 5-9 to create schedules for other operation scenarios. How to Activate a Scenario Scheduler When first created, a scenario scheduler is not automatically activated. To activate it, follow these steps: 1. Go to the operation scenarios’ folder within your project using the data manager. 2. Right-click the scenario scheduler object that you wish to activate and choose the option Activate from the context sensitive menu. The operation scenario validity periods defined within the scenario scheduler will now determine whether an operation scenario is activated automatically based on the study case time. Note: It is possible to create more than one scenario scheduler per project. However, only one may be active. Also, if you have defined overlapping validity periods for operation scenarios within the scenario scheduler, then the operation scenario listed first (lowest row index) in the scenario scheduler will be activated and all other scenarios ignored.

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14.5. ADVANCED CONFIGURATION OF OPERATION SCENARIOS

14.5

Advanced Configuration of Operation Scenarios

This sub-section describes some advanced configuration options for the operation scenarios. This includes adjusting the automatic save settings and modifying the data that is stored within the operation scenarios. Note for new users, it is recommended to use the default settings.

14.5.1

How to change the automatic save settings for Operation Scenarios

As mentioned in Section 14.3.2, by default operation scenarios do not automatically save your modifications to the network data operational parameters at the time the changes are made. As a user, you can enable automatic saving of operation scenario data and you can alter the automatic save interval. It is also possible to change the save interval to 0 minutes so that all operational data changes are saved as soon as the change is made. To change the save interval for operation scenarios, follow these steps: 1. Open the PowerFactory User Settings by clicking the (

icon on the main toolbar).

2. Select the Data Manager page. 3. In the operation scenario section of the page, enable the option Save active Operation Scenario automatically. 4. Change the Save Interval time if you would like to alter the automatic save interval from the default of 15 minutes. Setting this value to 0 minutes means that all operation scenarios will be saved automatically as soon as operational data is modified. Note: If an operation scenario is active any changes to the network model operational parameters are stored within such an scenario. If no operation scenario is active, then the changes are stored within the network model as usual, within a ’grid’ or within a ’recording expansion stage’. A changed operation scenario is marked by a “* " next to the operation scenario name in the status bar. In the data manager the modified operation scenario and operation scenario subset are also marked ( ).

14.5.2

How to modify the data stored in Operation Scenarios

Background PowerFactory defines a default set of operational data for each object within the network model. This is the information that is stored within the operation scenarios. However, it is possible to alter the information that is stored to a limited extent by creating a Scenario Configuration. The procedure is divided into two tasks. Firstly, a special Scenario Configuration folder must be created and then the object definitions can be created within this folder. Task 1: Creating a Scenario Configuration Folder To create a scenario configuration folder follow these steps: 1. Go to the Settings folder within the project using the data manager. 2. Click the New Object icon

. A object selection window will appear.

3. Choose the Scenario Configuration (SetScenario). A scenario configuration dialog will appear. You can rename it if you like. 4. Press OK.

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CHAPTER 14. OPERATION SCENARIOS Task 2: Defining the Operational Data Parameters Once you have created the scenario configuration folder (task 1 above), then you can create the object definitions that determine which parameters are defined as operational data. Follow these steps: 1. Deactivate any active operation scenario. 2. Open the Scenario Configuration folder object using the data manager. 3. Press the Default button. PowerFactory then automatically creates the object definitions according to the defaults. 4. Open the object definition that you would like to change by double clicking it. The list of default operational data parameters is shown in the Selected Variables panel of the dialog box that appears. 5. You can remove an operational parameter of this object by double clicking the target parameter from the Selected Variables panel. Likewise, a variable can be added to this list by clicking the black triangle underneath the cancel button and then adding the variable name to the list of parameters. 6. Once you have altered the defined parameters, click OK. 7. Repeat steps 4-6 for as many objects as you would like to change. 8. Open the scenario configuration folder object again (step 2) and press the Check button. PowerFactory will notify you in the output window if your changes are accepted. Note: Some variables cannot be removed from the default operational parameters due to internal dependencies. If you need to remove a certain variable but the check function doesn’t allow you to, it is suggested that you contact DIgSILENT support to discuss alternative options.

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Chapter 15

Network Variations and Expansion Stages 15.1

Introduction

As introduced in Chapter 4 (PowerFactory Overview), Variations and Expansion Stages are used to store changes to network data, such as parameter changes, object additions, and object deletions. This Chapter describes how to define and manage Variations, and presents an example case. The term “Variation" is used to collectively refer to Variations and Expansion Stages. The use of Variations in PowerFactory facilitates the recording and tracking of data changes, independent of changes made to the base Network Model. Data changes stored in Variations can easily be activated and deactivated, and can be permanently applied to the base Network Model when required (for example, when a project is commissioned). The concept of having a “permanent graphic" in PowerFactory means that graphical objects related to Variations are stored in Diagrams folders, and not within Variations. When a Variation is inactive, it’s graphic (if applicable) is shown on the Single Line Graphic in yellow. Turning on Freeze Mode ( ) hides inactive variations graphics. When a project uses Variations, and the user wants to make changes to the base network model directly, Variations should be deactivated, or the Study Time set to be before the activation time of the first Expansion Stage (so that there is no recording Expansion Stage). In general there are two categories of data changes stored in Variations: 1. Changes that relate to a future project (e.g. a potential or committed project). The changes may be stored in a Variation to be included with the Network Model at a particular date, or manually activated and deactivated as required by the user. 2. Changes that relate to data corrections or additions based on the current (physical) network. The changes may be stored in a Variation in order to assess the model with and without the changes, to track changes made to the model, and to facilitate reversion to the original model in case the changes are to be revised. Notes regarding Variations and Expansion Stages: • General: – The user may define as many Variations and Expansion Stages as required. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 15. NETWORK VARIATIONS AND EXPANSION STAGES – Variations and Expansion Stages cannot be deleted when active. – Variations may also be used to record operational data changes, when there is no active Operation Scenario. – Expansion Stages are by default sorted according to their activation time in ascending order. – To quickly show the recording Expansion Stage, project name, active Operation Scenario, and Study Case, hover the mouse pointer over the bottom right corner of the PowerFactory window, where (by default) the project name is shown. To change this to display the recording Expansion Stage, choose Display Options → ’Recording’ Expansion stage. • Activating and deactivating Variations: – Active Variations and Expansion Stages are shown with red icons in the Data Manager. – The Activation Time of Expansion Stages can only be modified when the parent Variation is inactive. – To activate or deactivate single or multiple Variations in the Data Manager, navigate to the “Variations" folder, select and right-click on the Variation(s) and choose to activate or deactivate the selected Variation(s). – In the active Study Case, the “Variation Configuration" object stores the status of project Variations. It is automatically updated as Variations are activated and deactivated. • Recording changes: – Elements in PowerFactory generally include references to Type data. Changes to Type data are not recorded in Expansion Stages. However, changes to Element Type references are recorded. – When there are multiple active Expansion Stages, only the ’Recording’ Expansion Stage stores changes to Network Data (shown with a dark red icon and bold text). There can be only one recording Expansion Stage per study case. – With the exception of objects added in the active ’Recording’ Expansion Stage, objects (e.g. Terminals in the base network model) cannot be renamed while there is a ’Recording’ Expansion Stage. • DPL: – Deleted objects are moved to the PowerFactory Recycle Bin, they are not completely deleted until the Recycle Bin is emptied. If a DPL script is used to create an Expansion Stage, and Expansion Stage objects are subsequently deleted, re-running the DPL script may first require the deleting of the Expansion Stage objects from the Recycle Bin. This is to avoid issues with references to objects stored in the Recycle Bin.

15.2

Variations

To define a new Variation (IntScheme): 1. First, either: • From the Main Menu, select Insert → Variation. • In a Data Manager, right-click on the Variations folder ( menu select New → Variation.

) and from the context-sensitive

• In a Data Manager, select the Variations folder and click on the New Object icon that the Element field is set to Variation (IntScheme), and press Ok.

. Ensure

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15.3. EXPANSION STAGES 4. On the second page of the Basic Data tab, optionally select to Restrict Validity Period of the Variation. The “starting" and “completed" Activation Time are set automatically according to the Expansion Stages stored inside the Variation. The “starting" time is the activation time of the earliest Expansion Stage, and the “completed" time is the activation time of the latest Expansion Stage. If no Expansion Stages are defined, the activation time is set by default to 01.01.1970. To activate a previously defined Variation, in the Data Manager, right-click on the Variation and from the context-sensitive menu select Activate. The Variation and associated Expansion Stages will be activated based on their activation times and the current study case time. In the Variation dialogue, the Contents button can be used to list the Expansion Stages stored within the Variation.

15.3

Expansion Stages

To define a new Expansion Stage (IntSstage): 1. First, either: • Right-click on the target Variation and select New → Expansion Stage. in the Data Manager’s icon • Select the target Variation and click on the New Object button bar. Set the ’Element’ field to Expansion Stage (IntStage) and press Ok. 2. Define the Expansion Stage Name. 3. Set the Expansion Stage Activation Time. 4. Optionally select to Exclude from Activation to put the Expansion Stage out of service. 5. Optionally enter Economical Data on the Economical Data page (see Chapter 34 (Techno-Economical Calculation) for details). 6. Press OK. 7. Select whether or not to set the current Study Time to the Activation Time of the defined Expansion Stage. See Section 15.5 for details. From the Expansion Stage dialogue, the following buttons are available: • Press Contents to view changes introduced by the Expansion Stage. • Press Split to assign changes from the recording Expansion Stage to a target (see Section 15.8.3). • Press Apply to apply the changes of an Expansion Stage (only available if the parent Variation is inactive). Changes are applied to the Network Model, or to the recording Expansion Stage (see Section 15.8.1).

15.4

The Study Time

The study case Study Time determines which Expansion Stages are active. If the Study Time is equal to or exceeds the activation time of an Expansion Stage, it will be active (provided that the parent Variation is active, and provided that “Exclude from Activation" is not selected in the Expansion Stage or an active Variation Scheduler). The Study Time can be accessed from: DIgSILENT PowerFactory 15, User Manual

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CHAPTER 15. NETWORK VARIATIONS AND EXPANSION STAGES • The Date/Time of Calculation Case icon

.

• Clicking on the lower right corner of the PowerFactory window, where the time of the active Study Case is displayed. • The Main Menu under Edit → Project Data→ Date/Time of Study Case, or Edit → Project Data→ button. Study Case and then the • The Data Manager in the active Study Case folder, object “Set Study Time".

15.5

The Recording Expansion Stage

When a Variation is activated for a study case, the active Expansion Stage with the latest activation time is automatically set to the recording Expansion Stage. If there are multiple Expansion Stages with this same activation time, the stage that previously set to the recording stage will remain as the recording Expansion Stage. Changes made to the network data by the user are saved to this stage. As discussed previously, the Study Time can be changed in order to set the active Expansion Stages, and as a consequence, set the “recording Expansion Stage". To simplify selection of the recording Expansion Stage, in the Data Manager it is possible right-click an Expansion Stage, and select Set ’Recording’ Expansion stage to quickly modify the Study Time to set a particular Expansion Stage as the recording Expansion Stage. As noted in 15.1, unless an Operation Scenario is active, changes made to operational data are stored in the recording Expansion Stage.

15.6

The Variation Scheduler

As an alternative to setting the activation time of Expansion Stages individually, Variation Schedulers (IntSscheduler ) may be used to manage the activation times and service status of each Expansion Stage stored within a Variation. Multiple Variation Schedulers can be defined within a particular Variation, but only one may be active at a time. If there is no active Variation Scheduler, the Expansion Stage activation times will revert to the times specified within each individual Expansion Stage. To define a Variation Scheduler: 1. Open a Data Manager, and navigate to the Variation where the Scheduler is to be defined. Then, either: • Right-click on the Variation and select New → Variation Scheduler. • Click on the New Object button

and select Variation Scheduler (IntScheduler).

2. Press the Contents button to open a data browser listing the included stages with their activation times and service statuses, and modify as required. The activation time and status of Expansion Stages referred to be a Variation Scheduler can only be changed when the Variation is active, and the Variation Scheduler is inactive. Note that Expansion Stage references are automatically updated in the scheduler. Note: If the parent Variation is deactivated and reactivated, the Variation Scheduler must be re-activated by the user, if required.

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15.7. VARIATION AND EXPANSION STAGE EXAMPLE

15.7

Variation and Expansion Stage Example

Figure 15.7.1 shows an example project where there are two Variations, “New Connection" and “New Line". The study time is set such that: • Expansion Stage “Ld1", shown with a light red icon and bold text, is active and is the recording Expansion Stage. • Expansion Stage “Ld2", shown without any colouring, is inactive. • Expansion Stage “Line and T2", shown with a dark red icon, is active. The Variation Scheduler “Scheduler1" within the “New Connection" Variation, shown with a red icon and bold text, is active. Therefore, the activation time and service status of each Expansion Stage within the Variation “New Connection" is determined from the activation times specified in this Variation Scheduler. The alternative Variation Scheduler “Scheduler2" is inactive (only one Variation Scheduler can be active at a time). Also shown in Figure 15.7.1 on the right-side pane are the modifications associated with Expansion Stage “Ld1". In this stage, a load and an associated switch and cubicle has been added. Note that since graphical objects are stored within the Diagrams folder, no graphical changes are included in the Variation.

Figure 15.7.1: Example Variations and Expansion Stages - Data Manager

Figure 15.7.2 shows the Single Line Graphic of the associated network. Since the Expansion Stage “Ld2" is inactive, the Load “Ld2" is shown in yellow.

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Figure 15.7.2: Example Variations and Expansion Stages - Single Line Graphic

15.8

Variation and Expansion Stage Housekeeping

15.8.1

Applying Changes from Expansion Stages

Changes stored in non-active Expansion Stages can be applied to the Network Data folder, or if there is an active recording Expansion Stage, to the recording Expansion Stage. To apply the changes, either: • In the Data Manager, right-click the Expansion Stage and select Apply Changes, or in the Expansion Stage dialogue press Apply (only available if the Expansion Stage is within a non-active Variation). • In the Data Manager, select item(s) within an inactive Expansion Stage, right-click and select Apply Changes. If required, delete the item(s) from the original Expansion Stage.

15.8.2

Consolidating Variations

Changes that are recorded in a projects active Variations can be permanently applied to the Network Data folder by means of the Consolidation function. After the consolidation process is carried out, the active (consolidated) Expansion Stages are deleted, as well as any empty active Variations. To consolidate an active Variation(s): 1. Right-click on the active study case and from the context-sensitive menu select Consolidate Network Variation. 2. A confirmation message listing the Variations to be consolidated is displayed. Press Yes to implement the changes. 3. View the list of consolidated Variations and Expansion Stages in the Output Window

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Note: Variations stored within the Operational Library must be consolidated in separate actions. To consolidate a Variation stored in the Operational Library, right-click and from the context-sensitive menu select Consolidate.

15.8.3

Splitting Expansion Stages

Changes stored in the recording Expansion Stage can be split into different Expansion Stages within the same Variation using the Merge Tool. To split an Expansion Stage: 1. Open the dialogue of the recording Expansion Stage and press Split. Alternatively, right-click and from the context-sensitive menu select Split. 2. A data browser listing the other Expansion Stages from the parent Variation is displayed. Doubleclick on the target Expansion Stage. 3. The Merge Tool window is displayed, listing all the changes from the compared Expansion Stages. Select the changes to be moved to the “Target" stage by double-clicking on the Assigned from cell of each row and selecting Move or Ignore. Alternatively, double-click the icon shown in the “Target" or “Source" cell of each row. 4. Press Split. All the changes marked as Move will be moved to the target Expansion Stage, and the changes marked as Ignore will remain in the original “Base" stage. Once completed, the Variation is automatically deactivated.

15.8.4

Comparing Variations and Expansion Stages

Variations and Expansion Stages can be compared, as can any other kind of object in PowerFactory, using the Merge Tool. To compare objects using the Merge Tool, a “base object" and an “object to compare" must be selected. The comparison results are presented in a data browser window, which facilitates the visualization, sorting, and possible merging of the compared objects. Comparison results symbols indicate the differences between each listed object, defined as follows: •

The object exists in the “base object" but not in the “object to compare".

•

The object exists in the “object to compare" but not in the “base object".

•

The object exists in both sets but the parametersŠ values differ.

•

The object exists in both sets and has identical parameter values.

To compare two Variations: 1. In an active project, right-click on a non-active Variation and from the context-sensitive menu select Select as Base to Compare. 2. Right-click on the (inactive) Variation to compare and from the context-sensitive menu select Compare to "Name of the base object". 3. The Merge Tool dialogue (ComMerge) is displayed. By default, all of the contained elements are compared. The Compare fields can be configured however, to compare only the objects or selected subfolders. 4. Once the Compare options are set, press the Execute button. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 15. NETWORK VARIATIONS AND EXPANSION STAGES 5. When prompted, select Yes to deactivate the project and perform the comparison. Figure 15.8.1 shows an example comparison of two Variations (based on the example presented in Section 15.7), where the Variation “New Line" is set as the “Base" for comparison. The “Assigned from" options are set such that all Expansion Stages from both “New Line" and “New Connection" Variations will be merged into a single Variation, which will retain the name of the “Base" Variation “New Line".

Figure 15.8.1: Merge Tool Window

Refer to Chapter 18: Data Management, Section 18.4 (Comparing and Merging Projects) for further details on use of the Merge Tool.

15.8.5

Colouring Variations the Single Line Graphic

offers three modes which may be used to identify changes The single-line graphic colouring function from Variations and Expansion Stages. To set the colouring mode, go to Diagram Colouring, and under Other select Variations / System Stages, and the desired mode from the following: • Modifications in Recording Expansion Stage. Colours can be defined for Modified, Added, and Touched but not modified components. • Modifications in Variations / System Stages. Objects are shown in the colour of the Variation in which the object is last added or modified. • Original Locations. Objects are shown in the colour of the grid or the Variation in which the object is added.

15.8.6

Variation Conflicts

Active Expansion Stages with the same activation time must be independent. This means that the same object can not be changed (modified, deleted, or added) in active Expansion Stages with the same 218

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15.8. VARIATION AND EXPANSION STAGE HOUSEKEEPING activation times. If there are dependent Expansion Stages, when the Variation is activated PowerFactory will display an error message to the Output Window and the activation process will be cancelled. Other conflicts that may arise during the activation of a Variation: • The same object is added by more than one Expansion Stage. In this case the latest addition is applied and a warning message is displayed in the Output Window. • A previously deleted object is deleted. In this case the deletion is ignored and a warning message is displayed in the Output Window. • An object is changed or deleted in a Expansion Stage but it does not exist. In this case the change is ignored and a warning message is displayed in the Output Window. • A deleted object is changed in a Expansion Stage. In this case the change is applied to the deleted target object and a warning message is displayed in the Output Window.

15.8.7

Error Correction Mode

As well as recording the addition and removal of database objects, variations also record changes to database objects. Human error or the emergence of new information can result in a need to update a change. Suppose that at some time after the change has been introduced, the user wishes to update the change. If additional variations have been created since the change was introduced, this will be hard to achieve. The user must first remember in which Expansion Stage the change was introduced, then they must make this Expansion Stage the Recording Stage before finally updating the change or rectifying the error. The Error Correction mode is intended to simplify this procedure. The following example illustrates use of the Error Correction Mode. Suppose that a project is planned consisting of a base case and 2 Variations, namely Variation 1 and Variation 2. Suppose that the base case network contains a line object (ElmLne) of length 1km. When Variation 1 is recorded, the length of the line is updated from the base case value to a new value of 10km. This change is recorded in the Expansion Stage associated with Variation 1. Subsequently, the user creates Variation 2 and records a new set of changes in the Expansion Stage of Variation 2. The user makes no changes to the line object in Variation 2, but suddenly realises that the length of the line is incorrect. The length should be 15km not 10km. If the user makes a change to the line length while Variation 2 is recording this change will be recorded and applied while Variation 2 is activated. However, as soon as Variation 2 is deactivated, providing Variation 1 is activated, the line length will return to the 10km value. This is incorrect and the error is therefore still present in the project. Instead of recording the change in the Recording Expansion Stage of Variation 2, the user should turn on the Error Correction Mode. This can be achieved by first ensuring that the Project Overview Window is visible. (If not, select Window → Show Project Overview Window). Then, by Right clicking in the Project Overview Window on the title line of the Network Variations section. A contextual menu as illustrated in Figure 15.8.2 will appear. The option Error Correction Mode should be selected from the contextual menu.

Figure 15.8.2: Activating Error Correction Mode

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CHAPTER 15. NETWORK VARIATIONS AND EXPANSION STAGES Once the Error Correction Mode has been switched on, any changes introduced will now, not automatically be stored in the Recording Expansion Stage. Instead, they will be stored in the Expansion Stage containing the record of the last change to the object in question. For the example described, this will be in the Expansion Stage associated with Variation 1, where the length was updated from 1km to 10km. The 10km value will be updated to 15km. If the Error Correction Mode is now switched off, again by right clicking in the Project Overview Window, the user can proceed knowing that the error has been eliminated from the project. Please note, if any change to the line had been recorded during Variation 2 prior to the application of the Error Correction Mode, not necessarily a change to the length of the line, but a change to any ElmLne parameter, then with Error Correction Mode active, the change would be recorded in the Recording Expansion Stage of Variation 2. This is because the Expansion Stage containing the record of the last change to the object in question would infact be the one in Variation 2. In this case, the error would still be present in the project.

15.9

Compatibility with Previous PowerFactory Releases

15.9.1

General

Prior to PowerFactory v14, “System Stages" where used to analyze design alternatives as well as different operating conditions. They recorded model changes (addition/removal of equipment, topology changes, etc.), operational changes (switch positions, tap positions, generator dispatch, etc.), and graphical changes. Since version 14.0, the System Stage definition has been replaced by Variations and Operation Scenarios, which provides enhanced flexibility and transparency. When importing (and then activating) a project that was implemented in a previous PowerFactory version, the activation process will automatically make a copy of the project, rename it (by appending _v14 or _v15 to the project name) and migrate the structure of the copied project. The migration process creates new Project Folders (such as Network Data, Study Cases, Library folders, etc.) and moves the corresponding information to these project folders. Additionally, existing Stations and Line Routes elements are migrated to their corresponding definition in v14 and v15 (i.e. Substations and Branches). If the project contains System Stages, they will not be converted automatically. They will be still be defined, and functions related to their handling will still be available. If the user wishes to take full advantage of the Variation and Operational Scenario concepts, then the System Stages must be converted manually. The procedure is described in the following section.

15.9.2

Converting System Stages

The conversion process of System Stages is described with reference to an example project opened in PowerFactory v14, with the structure shown in Figure 15.9.1. The project contains three grids “Grid 110 kV", “Grid 220 kV" and “Grid 33 kV". Each Grid contains a “2010 Base Case" System Stage with three System Stages “2010 MAX", “2010 MIN", and “2011 Base Case". The “2011 Base Case" stage in-turn contains two stages, “2011 MAX" and “2011 MIN". The Study Cases are configured so that the “2011 MAX" Study Case and the “2011 MAX" stages are active.

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Figure 15.9.1: Example Project - System Stage Structure

To convert the System Stages to Variations / Operation Scenarios: 1. Activate the Study Case that uses the base grids (in this example “Base Case 2009"), so that no System Stage is active. 2. Create a Variations folder inside the Network Data folder by opening the Data Manager window and from the left pane select the Network Data folder (located inside the Network Model folder), right-click and select New → Project Folder. In the dialogue window that appears, type in a name (for example “Variations") and select “Variations" as the folder type. Press OK. 3. Define a Variation inside the Variations folder. From the Data Manager window select the Variations folder, right-click and select New → Variation. In the dialogue window that appears, type in a name (for example “2010"). Press OK, and select Yes to activate the new Variation.

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CHAPTER 15. NETWORK VARIATIONS AND EXPANSION STAGES 4. The Expansion Stage dialogue will be displayed. Type in a name and set the activation time as appropriate (in this case, it is set to 01.01.2010). Press OK, and select Yes to set the stage as recording. After this step, the Variation should be active and the Expansion Stage be recording. 5. From the Data Manager, select a Study Case that uses System Stages (it should not be active), right-click and select Reduce Revision. This will copy both network data and operational data from the System Stages used by the study case into the recording Expansion Stage, and will delete the System Stages (to copy operational data to an Operation Scenario, an Operation Scenario must be active at this step). In this example, the “2010 Base Case" is reduced, followed by the “2011 Base Case" - this is because the complete System Stage branch, containing all System Stages between the selected stage and the target folder are reduced. Figure 15.9.2 shows the result of reducing the “2010 Base Case" and “2011 Base Case" to Variations.

Figure 15.9.2: Reduce Revision performed for the 2011 Base Case 6. After converting System Stages “2010 Base Case" and “2011 Base Case" (with Network Data modifications) to Variations, and System Stages “2010 MAX", “2010 MIN", “2011 MAX", and “2011 MIN" (with operational modifications) to Operation Scenarios, the Variations and Operation Scenarios are assigned to Study Cases. Figure 15.9.3 shows the resulting project structure for this example, where all System Stages have been converted to Variations and Operation Scenarios.

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Figure 15.9.3: Resulting Project Structure

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Chapter 16

Parameter Characteristics, Load States, and Tariffs 16.1

Introduction

This chapter provides details on how to define and use characteristics, load states, load distribution states, and tariffs.

16.2

Parameter Characteristics

General Background In PowerFactory any parameter may be assigned a range of values (known as a Characteristic) that is then selectable by date and time, or by a user-defined trigger. The range of values may be in the form of a one-dimensional vector or a two-dimensional matrix, such as where: • Load demand varies based on the minute, day, season, or year of the study case. • Generator operating point varies based on the study being conducted. • Line/transformer ratings, generator maximum power output, etc. vary with ambient temperature. • Wind farm output varies with wind speed, or solar farm output varies with irradiance. The assignment of a characteristic may be made either individually to a parameter or to a number of parameters. New characteristics are normally defined in either: • The Characteristics folder of the Operational Library. • The Global Characteristics folder within Database → Library. Studies which utilize characteristics are known as ’parametric studies’. Scales and Triggers The value of the characteristic is defined by the value of the scale. New scales are normally defined in the Scales folder of the Operational Library.

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CHAPTER 16. PARAMETER CHARACTERISTICS, LOAD STATES, AND TARIFFS When a scale is created, a means to ’set’ the scale, and thereby to set the parameter to the correspond). After a new scale has been defined, ing value, is required. This is called a trigger (SetTrigger, a trigger is automatically created in the active study case folder (see also Chapter 11, Section 11.13: Triggers). When a trigger is edited and a ’current’ value is set the scale is set and the parameter value is changed. When a different study case is activated, or a new study case is created, and a load-flow is performed, all relevant triggers are copied into the study case folder and may be used in the new study case. Triggers for characteristics may be created at any time in the Data Manager within the Library → Operational Library → Characteristics→ Scale folder, or at the time the Characteristic is created. Triggers for characteristic can generally be accessed from either: • The Date/Time of Study Case icon ( • The Trigger of Study Case icon (

).

).

Figure 16.2.1 illustrates an application of scales and triggers, where the study case time is used to set the output of a load based on the hour of the day.

Figure 16.2.1: Illustration of Scales and Triggers

Available Characteristics Table 16.2.1 shows a summary of the Parameter Characteristics available in PowerFactory. Note: Click on Characteristic description to link to the relevant section.

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16.2. PARAMETER CHARACTERISTICS Characteristic 16.2.1: Time Characteristics

16.2.2: Profile Characteristics 16.2.3: Scalar Characteristics 16.2.4: Vector Characteristics with Discrete Scales 16.2.4: Vector Characteristics with Continuous Scales 16.2.4: Vector Characteristics with Frequency Scales 16.2.4: Vector Characteristics with Time Scales 16.2.5: Matrix Parameter Characteristics 16.2.6: Parameter Characteristics from Files 16.2.7: Characteristic References

Description of Application Parameter(s) are to be modified based on the day, week, or month set in the Study Time. Parameter states may be interpolated between entered values. Parameter(s) are to be modified according to seasonal variation and the day, week and month set in the Study Time. Parameter(s) are to be manually modified by a scalar value. Discrete parameter states are to be selectable. Parameter states may be interpolated between entered values. Parameter(s) are to be modified with Frequency. Parameter(s) are to be modified based on a user-defined scale referencing the Study Time. Parameter states are based on two variables, and may be interpolated between entered values. Parameter states and the trigger (optional) is to be read from a file. Reference link between a parameter and a Characteristic

Table 16.2.1: Summary of Parameter Characteristics

Usage With the exception of the Scalar Characteristic, the “Usage" field at the bottom of the characteristic dialogue can be used to specify how “Values" are applied to the parameter that the characteristic is associated with: • Relative in % will multiply the parameter by the percentage value. • Relative will multiply the parameter by the value. • Absolute will replace the current parameter with the absolute value entered. Characteristic Curves For continuous characteristics, various approximation methods are available to interpolate and extrapolate from the entered Values: • Constant: holds the Y-value in between X-values. • Linear: uses a linear interpolation. • Polynomial: uses a polynomial function with a user defined degree. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 16. PARAMETER CHARACTERISTICS, LOAD STATES, AND TARIFFS • Spline: uses a spline function. • Hermite: uses Hermite interpolation. The approximation curve will be shown in the diagram page of the Characteristic dialogue. The interpolated Y-value may vary considerably depending on the entered data and the approximation function applied. Figure 16.2.2 highlights the difference between interpolation methods for an example characteristic with a continuous scale (shown on the horizontal axis from -20 to +45). For instance, at a trigger value of 25, linear interpolation will give an output value of 60, whereas constant interpolation will give an output value of 40.

Figure 16.2.2: Approximated characteristics

Note that Approximation methods are not available for discrete characteristics. Creating a Characteristic To create a Characteristic, right-click on the desired parameter (e.g. ’Active Power’), right-click and select New Characteristic (or edit previously created characteristics) and create the desired characteristic. Details of how to create the different types of characteristics are provided in the following sub-sections, including an example application of characteristics.

16.2.1

Time Characteristics

General background on characteristics and their properties is provided in Section 16.2. The time characteristic determines the value of the parameter according to the study time (SetTime). The time char228

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16.2. PARAMETER CHARACTERISTICS acteristic (ChaTime) uses an internally defined Recurrence period that is convenient to define a periodically recurring characteristic. The user simply selects a Recurrence and enters the corresponding values. The Recurrence values available are: • Daily • Weekly • Monthly • Yearly • None There are two options for defining the data source of values used in a time characteristic, Table and File. The Table data is stored internally within PowerFactory . The File data is stored externally to PowerFactory in a Comma Separated Values (*.csv) file or User Defined Text File. Time characteristic using internal table To define a project time characteristic for a parameter using a table: • In the edit dialogue of the target network component right-click on the desired parameter. • Select Add Project Characteristic → Time Characteristic . . . • Click the New Object button • The edit dialogue of the Time Characteristic will be displayed. Define the parameter name and select ’Data Source’ Table. • Select the desired ’Recurrence’ and the ’Resolution’. • Define the ’Usage’ and ’Approximation’ and enter the characteristic values in the table. • Press Ok. Time characteristic using an external file To define a project time characteristic for a parameter using an external file: • In the edit dialogue of the target network component right-click on the desired parameter. • Select Add Project Characteristic → Time Characteristic . . . • Click the New Object button • The edit dialogue of the Time Characteristic will be displayed. Define the parameter name and select ’Data Source’ File. • Select the desired ’Filename’ and file ’Format’. • Define the file configuration including the ’Unit’ of time or ’Time Stamped Data’ format, ’Time Column’ and ’Data Column’ and ’Column separator’ and ’Decimal separator’. • Define the ’Usage’ and ’Approximation’. • Press Ok. Discrete Time Characteristics The discrete time characteristic (ChaDisctime) is provided for backward compatibility with previous versions of PowerFactory . It is more restricted than the time characterisitc and hence its use is limited since PowerFactory version 15.1. Similar to the time characteristic, the discrete time characteristic uses an internally defined series of time scales that are convenient to use to define the characteristic. The user simply selects a scale (e.g. day of the week) and enters the corresponding values. DIgSILENT PowerFactory 15, User Manual

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16.2.2

Profile Characteristics

General background on characteristics and their properties is provided in Section 16.2. The profile characteristic is used to select a time characteristic (ChaTime) corresponding to individual days or group of days and each season. The profile characteristic can also be used to select a time characteristic for certain holiday days. To define a project profile characteristic for a parameter: • In the edit dialogue of the target network component right-click on the desired parameter. • Select Add Project Characteristic → Profile Characteristic ... • Click the New Object button • The edit dialogue of the Profile Characteristic will be displayed. • Select the ’Seasons’ page and define one or more seasons with a ’Description’, ’Start Day’, ’Start Month’, ’End Day’ and ’End Month’. Note that Seasons can not overlap with each other. • Select the ’Groups of Days’ page and define grouping for each day and holiday. • Select the ’Holidays’ page and define one or more holidays with a ’Description’, ’Day’, ’Month’, if it is ’Yearly’ or select a holiday ’Year’. • Select the ’General’ page, Right Click and Select ’Select Element/Type . . . ’ or Double-Click on each relevant cell and select or create a time characteristics for each group of days, holiday and season. • Press Ok. Yearly Growth Characteristic In addition to seasonal characteristic variation, a yearly growth characteristic can also be defined. A yearly growth characteritic is defined using a time characteristic (ChaTime) with a recurrence value of "None", for the specified years. Note: All daily and yearly characteristics must be relative. No absolute-value characteristics are permissive

16.2.3

Scalar Characteristics

General background on characteristics and their properties is provided in Section 16.2. Scalar characteristics are used when a parameter should vary according to a mathematical relationship, with reference to a scale value “x". For example, a Parameter Characteristic may reference a Scalar and Trigger (TriVal) with a Unit of ’Temperature’. Then, if the temperature is set to, say, 15 deg, the parameter that this characteristic is applied to will thus be multiplied by 2 · 15 + 3 = 33. To define a project scalar characteristic for a parameter: • In the edit dialogue of the target network component right-click on the desired parameter (e.g. ’Active Power’). • Select Add Project Characteristic → Scalar Value. . . • Click the New Object button 230

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16.2. PARAMETER CHARACTERISTICS • The edit dialogue will be displayed. Click ’Select’ from the drop down menu next to ’Scale’ and select an existing scale and press Ok, or create a new scale: – Click on the ’New Object’ button to create a Scalar and Trigger (TriVal) and set the desired units of the scale. The associated trigger is automatically created in the current study case. – Press Ok. • Define the ’Usage’ and enter parameters for ’A’ and ’b’. • Press Ok.

16.2.4

Vector Characteristics

Vector Characteristics may be defined with reference to Discrete Scales, Continuous Scales, Frequency Scales, and Time Scales. Vector Characteristics with Discrete Scales (TriDisc) General background on characteristics and their properties is provided in Section 16.2. A discrete parameter characteristic is used to set the value of a parameter according to discrete cases set by the trigger of a discrete scale. A discrete scale is a list of cases, each defined by a short text description. The current value is shown in the characteristic dialogue in red, according to the case that is currently active. To define a new project discrete parameter characteristic: • In the edit dialogue of the target network component right-click on the desired parameter. • Select Add Project Characteristic → One Dimension Vector. . . • Click the New Object button • The edit dialogue of the one dimension vector characteristic (generic class for one dimensional characteristics) will be displayed. Click ’Select’ from the drop down menu next to ’Scale’ and select an existing scale and press Ok, or create a new scale: – Click on the New Object button and select Discrete Scale and Trigger (TriDisc). – Write the name of the scale cases (one case per line). – Press Ok twice. • Define the ’Usage’ and enter the characteristic values. • Press Ok. The diagram page for the discrete characteristic shows a bar graph for the available cases. The bar for the case that is currently active (set by the trigger) is shown in black. Vector Characteristics with Continuous Scales (TriCont) General background on characteristics and their properties is provided in Section 16.2. A continuous parameter characteristic is used to set the value of a parameter (’Y’ values) according to the ’X’ values set in the continuous scale. To define a new project continuous parameter characteristic: • In the edit dialogue of the target network component right-click on the desired parameter. • Select Add Project Characteristic → One Dimension Vector. . . DIgSILENT PowerFactory 15, User Manual

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CHAPTER 16. PARAMETER CHARACTERISTICS, LOAD STATES, AND TARIFFS • Click the New Object button • The edit dialogue of the one dimension vector characteristic (generic class for one dimensional characteristics) will be displayed. Click ’Select’ from the drop down menu next to ’Scale’ and select an existing scale and press Ok, or create a new scale: – Click on the New Object button and select Continuous Scale and Trigger (TriCont). – Enter the unit of the ’X’ values. – Append the required number of rows (right-click on the first row of the Scale table and select Append n rows) and enter the ’X’ values. – Press Ok. • Define the ’Usage’, enter the characteristic ’Y’ values, and define the ’Approximation’ function. • Press Ok. Vector Characteristics with Frequency Scales (TriFreq) General background on characteristics and their properties is provided in Section 16.2. A frequency characteristic is a continuous characteristic with a scale defined by frequency values in Hz. The definition procedure is similar to that of the continuous characteristics, although the Frequency Scale (TriFreq) is selected. Vector Characteristics with Time Scales (TriTime) General background on characteristics and their properties is provided in Section 16.2. Time parameter characteristics are continuous characteristics using time scales. A time scale is a special kind of continuous scale that uses the global time trigger of the active study case. The unit of the time trigger is always a unit of time but may range from seconds to years. This means that changing the unit from minutes to hours, for instance, will stretch the scale 60-fold. The units ’s’, ’m’, and ’h’ are respectively, the second, minute and hour of normal daytime. A Time Scale may be used, for example, to enter four equidistant hours in a year (1095, 3285, 5475, and 7665). The definition procedure is similar to that of the continuous characteristics, although the Time Scale (TriTime) scale is selected.

16.2.5

Matrix Parameter Characteristics

General background on characteristics and their properties is provided in Section 16.2. When defining a matrix parameter characteristic, two scales must be defined. The first scale, that for columns, must be a discrete scale. The scale for rows may be a discrete or continuous scale. To define a new project matrix parameter characteristic: • In the edit dialogue of the target network component right-click on the desired parameter. • Select Add Project Characteristic → Two Dimension - Matrix. . . • Click the New Object button • The edit dialogue of the matrix characteristic will be displayed. Click ’Select’ from the drop down menu next to each ’Scale’ and select an existing scale and press Ok, or create a new scales. Scales can be defined as discussed in previous sections. A column calculator can be used to calculate the column values, as a function of other columns. This is done by pressing the Calculate. . . button. Once the values have been entered and the triggers have been set, the ’Current Value’ field will show the value to be used by the characteristic. 232

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16.2.6

Parameter Characteristics from Files

General background on characteristics and their properties is provided in Section 16.2. When a series of data is available in an external file, such as an Excel file, or tab or space separated file this data may be utilized as a characteristic if the “Parameter Characteristic from File" (ChaVecfile object) is used. The external file must have the scale column for the data series in column 1. To define a new parameter characteristic from file: • In the edit dialogue of the target network component right-click on the desired parameter. • Select New Characteristic → Characteristic from File. . . • Complete the input data fields, including: – Define (or select) a scale and trigger. Scales can be defined as discussed in previous sections. – Generally the ’Column’ should be set to the default of ’1’. The field is used for specialized purposes. – Set the ’Factor A’ and ’Factor B’ fields to adjust or convert the input data. The data contained in column 2 of the external file will be adjusted by 𝑦 = 𝑎𝑥 + 𝑏 where “x" is the data in the external file and “y" is what will be loaded into the characteristic. – Set the ’Usage’ and ’Approximation’. – Once the file link has been set, press the Update button to upload the data from the external file to the characteristic.

16.2.7

Characteristic References

When a characteristic is defined for an objects parameter, PowerFactory automatically creates a characteristic reference (ChaRef object). The characteristic reference is stored within the PowerFactory database with the object. The characteristic reference acts as a pointer for the parameter to the characteristic. The characteristic reference includes the following parameters: Parameter the name of the object parameter assigned to the characteristic. This field cannot be modified by the user. Characteristic the characteristic which is to be applied to the parameter. Inactive a check-box which can be used to disable to characteristic reference. The ability to disable the characteristic for individual objects using the object filter and the Inactivate option makes data manipulation using characteristics quite flexible.

16.2.8

Edit Characteristic Dialogue

Once a parameter has a characteristic defined, then an option to Edit characteristic(s) becomes visible on the parameters context sensitive menu, i.e. select parameter and right-click → Edit characteristic(s). Once selected, the Edit characteristics dialogue appears which lists all the characteristics referenced by the parameter. The Edit characteristics dialogue provides a graphical representation of the characteristic and allows characteristics to be inserted, appended and deleted. The Edit characteristics dialogue also allows modification of individual characteristics values, triggers and characteristic activation and deactivation. Note: By default the value of the first active characteristic is assigned to the parameter.

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16.2.9

Browser in ’Scales’ mode

A special display mode is available in the database browser to check and edit the characteristics for whole classes of objects. This ’Scales’ mode must be enabled in the User Settings, on the ’Functions’ page. An example of a browser showing the ’Scales’ page is shown in Figure 16.2.3 (remember that the browser must be in ’detail’ mode to see these tabs).

Figure 16.2.3: Browser in ’Scales’ mode

The browser in ’Scales’ mode shows all characteristics defined for the displayed objects, together with the original value and the current value as determined by the characteristic. In the example, various scales are applied to modify the active power from 100 MW to the ’Current Value’. The current values will be used in all calculations. The browser ’Scales’ mode is not only used to quickly inspect all defined characteristics, but may also be helpful in defining new characteristics for individual or multiple elements, by selecting the relevant fields and right-clicking with the mouse button. The ’Scales’ tab of the browser will only show the ’Characteristic’ column when at least one of the objects has a characteristic defined for a parameter. It is thus necessary to define a characteristic for one object prior to using the browser, when the user would like to assign characteristics, for the same parameter, for a range of other objects. To define a Project “High-Low" loading characteristic for all loads, for instance, can thus be done by performing the following steps. • Create a discrete scale in the grid folder. • Create a vector characteristic using this scale in the grid folder. • Edit one of the loads, right-click the active power field and assign the vector characteristic to the relevant parameter. • Open a browser with all loads, activate the ’detail’ mode and select the ’Scales’ tab. • Select the characteristic column (right-click → Select Column) and then right-click the selected column. • Use the Select Project Characteristic. . . option and select the vector characteristic.

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16.2.10

Example Application of Characteristics

Consider the following example, where the operating point of a generator should be easily modified by the user to predefined values within the capability limits of the machine. Firstly, the Active Power of the synchronous generator is set to the maximum capability of 150 MW. Then, a vector characteristic is added to the Active Power parameter. To create a new Project Vector Characteristic, right-click on the Active Power parameter (pgini) and select Add Profile Characteristic → One Dimension - Vector. . . . Click on the New Object icon and define a characteristic called "Active Power" in the ChaVec dialogue. A new discrete scale is required. To create the scale, click on the arrow next to Scale and select Select. . . . Click on the New Object icon and create a new Discrete Scale and Trigger (TriDisc). The Discrete Scale and Trigger is named "Output Level", with three cases as shown in Figure 16.2.4.

Figure 16.2.4: Active Power Discrete Scale and Trigger

Click on ok to return to the Vector Characteristic. Define the values for the different loading scenarios. Values are entered in %, and thus Usage is set to ’relative in %’. Figure 16.2.5 shows the resultant vector characteristic, including a reference to the Scale ’Output Level’ and the current parameter value.

Figure 16.2.5: Active Power Parameter Characteristic

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CHAPTER 16. PARAMETER CHARACTERISTICS, LOAD STATES, AND TARIFFS fashion to the Active Power characteristic. A new discrete scale named ’Operating Region’ is created (for the Columns) and three operating regions are defined (see Figure 16.2.6).

Figure 16.2.6: Reactive Power Discrete Scale and Trigger

The scale ’Operating Region’ is linked to the ’Scale for Columns’, and the previously defined scale ’Output Level’ is selected for the ’Scale for Rows’. Absolute Mvar values are entered in the Matrix Characteristic as shown in Figure 16.2.7.

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Figure 16.2.7: Reactive Power Matrix Characteristic

Now that the characteristics and triggers are defined, the ’Operating Region’ and ’Real Power Output Level’ triggers can be used to quickly modify the operating point of the generator (see Figure 16.2.8).

Figure 16.2.8: Setting of Discrete Triggers

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16.3

Load States

This section describes Load States, as used in Reliability and Optimal Capacitor Placement calculations.

16.3.1

Creating Load States

Pre-requisites: Prior to creating load states, a time-based parameter characteristics must be defined for at least one load in the network model. See Time Characteristics (ChaTime) in section 16.2.1 and Vector Characteristics with Time Scales (TriTime) in section 16.2.4 for more information on parameter characteristics, as well as the example later in this section. Follow these steps to create the load states: 1. For calculation of load states: • (Reliability) click the ’Create Load States’ icon ( ) on the reliability toolbar and select ’Load States’. Optionally inspect or alter the settings of the Reliability Calculation and Load Flow commands. • (Optimal Capacitor Placement) Click on ’Load Characteristics’ page of the Optimal Capacitor Placement command and select ’Create Load States’. 2. Enter the time period for calculation of load states: • (Reliability) Enter the year. • (Optimal Capacitor Placement) Enter Start Time and End Time. The time period is inclusive of the start time but exclusive of the end time. 3. Enter the Accuracy. The lower accuracy percentage, the more load states are generated. 4. Optional: Limit the number of load states to a user-defined value. If the total number of calculated load states exceeds this parameter then either the time period of the sweep or the accuracy should be reduced. 5. Optional: Change the threshold for ignoring load states with a low probability by altering the ’Minimum Probability’. If selected, states with a probability less than this parameter are excluded from the discretisation algorithm. 6. Click Execute to generate the load states.

16.3.2

Viewing Existing Load States

After you have generated the load states as described above, or if you want to inspect previously generated load states follow these steps: 1. Using the data manager, select the ’Reliability Assessment’ or ’Optimal Capacitor Placement’ Command within the Active Study Case. 2. Optional: Use the filter ( ) (in the Data Manager window) to select the ’load states’ object ( There should now be created load states visible in the right panel of the data manager.

).

3. Locate the ’load states’ object and double-click to view the load states.

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16.3.3

Load State Object Properties

The load states object properties are as follows: Basic Data Year The Year used to create the load states. • Number of loads: Number of loads considered in the load cluster object. • Number of states: This equals the number of columns in the “Clusters" table. • Loads: Table containing each load considered by the load states creation algorithm and their peak demand. • Clusters: Table containing all load clusters. The first row in the table contains the probability of the corresponding cluster. The remaining rows contain the power values of the loads. Every column in the table contains a complete cluster of loads with the corresponding power. Diagram Page Displayed Load: Use the selection control to change the load displayed on the plot. The plot shows the cluster values (P and Q) for the selected load where the width of each bar represents the probability of occurrence for that cluster in the given year.

16.3.4

Example Load States

The example below shows how load states can be generated for a network model with four Loads (Ld1, Ld2, Ld3, and Ld4). 1. The Vector Characteristic shown in Figure 16.3.1 is applied to both Active Power and Reactive Power of load Ld4 only, with the associated Time Scale shown in Figure 16.3.2 Ld4 is initially set to 3.1 MW, 0.02 Mvar.

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Figure 16.3.1: Load State Vector Characteristic

Figure 16.3.2: Time Scale for Load State Characteristic 2. Load States are generated by clicking ’Create... Load States’ (as discussed in the preceding section). 3. PowerFactory calculates the resultant Load States: • The maximum value of each load 𝐿𝑝 is determined for the time interval considered. In the 240

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16.4. LOAD DISTRIBUTION STATES example, Ld4 has a peak load of 4.03 MW. • The ’load interval size’ (𝐼𝑛𝑡) is determined for each load, where 𝐼𝑛𝑡 = 𝐿𝑝 · 𝐴𝑐𝑐 and ’Acc’ is the accuracy parameter entered by the user. For the example above using an accuracy of 10 %, the interval size for Active Power is 0.403 MW.# • For each (︀ 𝐿𝑖 )︀hour of the time sweep and for each load determine the Load Interval: 𝐿𝐼𝑛𝑡 = where 𝐿𝑖 is the load value at hour ’i’. 𝐶𝑒𝑖𝑙 𝐼𝑛𝑡 • Identify common intervals and group these as independent states. • Calculate the probability of each state based on its frequency of occurrence. The independent states and their probabilities are shown in Figure 16.3.3. Load states for Ld4 vary according to the characteristic parameters, where the states from characteristic values of 93 % and 100 % have been combined due to the selection of 10 % accuracy in the calculation. Load states for Ld1, Ld2, and Ld3 do not vary, since characteristics were not entered for these loads.

Figure 16.3.3: Load States (SetCluster) dialogue box

16.4

Load Distribution States

This section describes how to create load distribution states, as used by the Reliability calculation.

16.4.1

Creating Load Distribution States

Pre-requisites: Prior to creating load distribution states a substation/s must have been defined within the model. A distribution curve must have also been defined (accessed from the reliability page of the substation/s). Follow these steps to create the load distribution states: 1. Click the ’Create Load States’ button ( dialogue will appear.

) on the reliability toolbar. The load states creation

2. Optional: Use the Reliability Assessment selection control to inspect or alter the settings of the Reliability Calculation command. This selection control points to the default reliability command within the active Study Case. 3. Optional: Use the Load Flow selection button to inspect and alter the settings of the load flow command. This selection control points to the default load-flow command within the active Study Case. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 16. PARAMETER CHARACTERISTICS, LOAD STATES, AND TARIFFS 4. Enter the Minimum Time Step in hours (suggested to be the minimum step size on the load distribution curve). 5. Enter the Maximum Power Step (0.05pu by default). 6. Optional: Force Load State at S = 1.0pu so that a state is created at P = 1.0pu, irrespective of the load distribution curve data and step sizes entered. 7. Click Execute to generate the load distribution states.

16.4.2

Viewing Existing Load Distribution States

After you have generated the load states as described above, or if you want to inspect previously generated load states follow these steps: 1. Using the data manager, select the ’Reliability Assessment’ Command within the Active Study Case. 2. Optional: Use the filter ( ) (in the Data Manager window) to select the ’load distribution states’ object ( ). There should now be created load distribution states visible in the right panel of the data manager. 3. Locate the ’load distribution states’ object and double-click to view the load states.

16.4.3

Load Distribution State Object Properties

The distribution load states object properties are as follows: Basic Data Year The Year used to create the load states. • Clusters: Table containing all substation clusters. The first row in the table contains the probability of the corresponding cluster. The remaining rows contain the power values of the substations. Every column in the table contains a complete cluster of substations with the corresponding power. • Number of substations: Number of substations considered in the Distribution State object. • Number of states: This equals the number of columns in the Distribution State table. Diagram Page Displayed Station: Use the selection control to change the load displayed on the plot The plot shows the cluster values (Apparent power in pu with reference to the substation load) for the selected substation where the width of each bar represents the probability of occurrence for that cluster.

16.4.4

Example Load Distribution States

In this example, a Load Distribution Curve is entered for a substation. 1. The Load Distribution Curve shown in Figure 16.4.1 is entered for the substation (Apparent power in pu of substation load).

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16.4. LOAD DISTRIBUTION STATES

Figure 16.4.1: Substation Load Distribution Curve (IntDistribution) 2. Load States are generated by clicking ’Create... Load Distribution States’ (as discussed in the preceding section). 3. The resultant Load Distribution States are shown in Figure 16.4.2. ’Force Load State at S = 1.0 p.u.’ has not been selected in this instance.

Figure 16.4.2: Load Distribution States (SetDistrstate)

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16.5

Tariffs

This section describes the definition of Time Tariffs (as used in Reliability calculations), and Energy Tariffs (as used in Reliability calculations and Optimal RCS Placement calculations, and Techno-Economical calculations).

16.5.1

Defining Time Tariffs

A time tariff characteristic can be defined by taking the following steps: 1. Choose the ’Select’ option from the ’Tariff’ selection control on the reliability page of the load element. A data manager browser will appear with the ’Equipment Type Library’ selected. 2. Optional: If you have previously defined a ’Tariff’ characteristic and want to re-use it, you can select it now. Press OK to return to the load element to reliability page. 3. Create a time tariff object by pressing the New Object button type creation dialogue should appear.

from the data browser toolbar. A

4. Select ’Time Tariff’ and press OK. A ’Time Tariff’ dialogue box will appear. 5. Select the unit of the interruption cost function by choosing from the following options: $/kW Cost per interrupted power in kW, OR $/customer Cost per interrupted customer, OR $ Absolute cost. 6. Enter values for the Time Tariff (right click and ’Append rows’ as required). 7. Press OK to return to the load element reliability page. 8. Optional: enter a scaling factor for the Tariff. Example Time Tariff An example Time Tariff characteristic is shown in Figure 16.5.1. In this example, ’Approximation’ is set to ’constant’, i.e. no interpolation between data points, and ’Unit’ is set to $. An interruption to a load for a duration of 200 minutes would lead to a cost of $20, irrespective of the active power consumption.

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Figure 16.5.1: Example Time Tariff

16.5.2

Defining Energy Tariffs

An energy tariff characteristic can be defined by taking the following steps: 1. Choose the ’Select’ option from the ’TariffŠ selection control on the reliability page of the load element. A data manager browser will appear with the ’Equipment Type Library’ selected. 2. Optional: If you have previously defined a ’Tariff’ characteristic and want to re-use it, you can select it now. Press OK to return to the load element to reliability page. 3. Create an energy tariff object by pressing the New Object button A type creation dialogue should appear.

from the data browser toolbar.

4. Select ’Energy Tariff’ and press OK. An ’Energy Tariff’ dialogue box will appear. 5. Enter Energy and Costs values for the Energy Tariff (right click and ’Append rows’ as required). 6. Press OK to return to the load element reliability page. 7. Optional: enter a scaling factor for the Tariff. Example Energy Tariff An example Energy Tariff characteristic is shown in Figure 16.5.2. In this example, ’Approximation’ is set to ’constant’, i.e. no interpolation between data points. A fault which leads to energy not supplied of 2.50 MWh would result in a cost of DIgSILENT PowerFactory 15, User Manual

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$9, 20 · 2, 50 · 1000 = $23000

(16.1)

Figure 16.5.2: Example Energy Tariff

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Chapter 17

Reporting and Visualizing Results 17.1

Introduction

This chapter presents the tools and options included in PowerFactory to view the results of the preformed calculations. Key concepts in this topic are Result Boxes, Virtual Instruments (VIs), Results Objects, and Variable Selection.

17.2

Results, Graphs and Documentation

This section presents the set of objects, commands and tools, dedicated to the handling and presentation of results in PowerFactory.

17.2.1

Editing Result Boxes

Results are displayed with help of result boxes in the single line diagrams, as described in Chapter 9: Network Graphics, Section 9.9 (Results Boxes, Text Boxes and Labels). To edit result boxes (e. g. for selecting additional variables to be displayed) the so-called Format Editor is used. With the Format Editor one can define text reports, from very small result boxes to more complex and comprehensive reports within DIgSILENT PowerFactory . For a detailed technical description of the report generating language, see Appendix E (The DIgSILENT Output Language). The Format Editor (IntForm) will be used in most cases to change the contents of the result boxes in the single line graphic. PowerFactory offers three ways in which to change a result box definition: • selecting three variables out of three predefined lists • selecting one or more variables out of all available variables • writing a new user defined format, using the PowerFactory Format Editor. Because of all these, the result boxes are used as example to introduce the nature and use of the Format Editor. As explained in Chapter 9: Network Graphics, Section 9.9.1 (Result Boxes) the result boxes may be right-clicked to select a particular format. Figure 17.2.1 shows the Format Editor dialogue.

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Figure 17.2.1: The Format Editor

Different variables can be added by appending new rows. The user should double click in the corresponding row in the column “Variable" and the list of all available variables will appear. This Format Editor has a page to change the format by selecting variables, and a page to manually define a format. What is displayed on this page depends on the input mode of the Format Editor, this can be changed using the button Input Mode.

Figure 17.2.2: The Format Editor - Selection Mode

As shown in Figure 17.2.2 the two modes are: User Selection This mode lets the user select any amount of parameters out of all available parameters for the selected object or class of objects. This includes model parameters as well as calculated values. 248

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It is also possible to define how the variable will be showed by selecting the columns Show Name, Show =, Decimal Places and Show Unit. A preview of the Result Box is showed in the Preview field. Format Editor This is the most flexible, but also the most difficult mode. In this mode, any text and any available variable, in any color, can be entered in the Form. The highly flexible DIgSILENT output language allows for complex automatic reports. This mode also offers a fast append of predefined lines. The User defined button acts like the input mode “User Selection" with one important difference. Where the “User Selection" mode is used to redefine the complete form text, the User defined button appends a line for each set of variables to the existing form text. In Figure 17.2.1, the editor is in the default ’User Selection’ mode. The three predefined rows show the names of the variables, their units and their descriptions. The example in Figure 17.2.1 shows that the active and reactive power at the element Xnet have been selected as well as power factor. This selection will produce three lines of DIgSILENT output language code. This code can be viewed by changing the Input Mode to “Format Editor". The text editor in this page will be disabled, because a format is selected instead of typing in the codes ourselves. However, it still shows the format of our selection as: #.## $N,@:m:P:_LOCALBUS #.## $N,@:m:Q:_LOCALBUS #.## $N,@:m:cosphi:_LOCALBUS This example shows the basic syntax of the DIgSILENT output language: • The ’#’ sign is a placeholder for generated text. In the example, each line has a placeholder for a number with two digits after the decimal point (’#.##’). The first ’#’-sign stands for any whole number, not necessary smaller than 10. • The ’$N’ marks the end of a line. A line normally contains one or more placeholders, separated by non-’#’ signs, but may also contain normal text or macro commands. • After the ’$N’, the list of variable names that are used to fill in the placeholders have to be added. Variable names must be separated with commas. Special formatting characters, like the ’@:’-sign, are used to select what is printed (i.e. the name of the variable or its value) and how. The Format Editor offers options for the unit or name of the selected variable. If the Unit-show option is enabled, a second placeholder for the unit is added: #.## # $N,@:m:P:_LOCALBUS,@:[m:P:_LOCALBUS #.## # $N,@:m:Q:_LOCALBUS,@:[m:Q:_LOCALBUS #.## $N,@:m:cosphi:_LOCALBUS,@:[m:cosphi:_LOCALBUS The ’[’-sign encodes for the unit of the variables, instead of the value. The same goes for the variable name, which is added as # #.## $N,@: m:P:_LOCALBUS,@:m:P:_LOCALBUS # #.## $N,@: m:Q:_LOCALBUS,@:m:Q:_LOCALBUS # #.## $N,@: m:cosphi:_LOCALBUS,@:m:cosphi:_LOCALBUS

Where the "∼" -sign encodes for the variable name. With both options on, the produced format line # #.## # $N,@: m:P:_LOCALBUS,@:m:P:_LOCALBUS,@:[m:P:_LOCALBUS DIgSILENT PowerFactory 15, User Manual

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CHAPTER 17. REPORTING AND VISUALIZING RESULTS will lead to the following text in the result box: P -199,79 MW Other often used format characters are ’%’, which encodes the full variable description, and ’&’, which encodes he short description, if available.

17.2.2

Output of Device Data

The ComDocu command (“Output of Device Data" ) is used to produce an output of device data. The output can be used in reports or may help to check the entered data. Reports of calculated results can be made with the ComSh command. See Section 17.2.3 (Output of Results) for more information. The Short Listing The “Short Listing" reports only the most important device data, using one line for each single object. This allows a small but clear documentation. Like the “Output of Results" the “Short Listing" report uses a form to generate the output. This form can be modified by the user. When the report form is changed, it is stored in the “Settings" object of the active project. This does not influence the reports of other projects. The output of objects without a defined short listing will produce warnings like: DIgSI/wrng - Short Listing report for StoCommon is not defined. The Detailed Report The detailed report outputs all device data of the elements selected for output. In addition, type data can be included (“Print Type Data in Element"). Device Data is split into the different calculation functions like “Load-Flow" or “Short-Circuit". The “Basic Data" is needed in all the different calculations. “Selected Functions" shows a list of the functions whose data will be output. If one wants to report the device data for all functions move all functions from left to right. If “Selected Functions" is empty no device data will be output. Device Data

Figure 17.2.3: Device data page

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17.2. RESULTS, GRAPHS AND DOCUMENTATION Use Selection The set of reported elements depends on the "Use Selection" setting. If "Use Selection" is checked one element or a "Set" object must be chosen for output. If "Use Selection" is not checked the "Filter/Annex" page specifies the set of elements for the report. This page is described further down. Another way to select object for the report is to select the objects in the "Data Manager" or the "Single Line" graphics and select "Documentation" in the "Output" entry of the context menu. The "Output of Device Data" command will pop up. Annex Each class uses it’s own annex. There is either the default annex or the individual annex. To use the default annex check "Use default Annex". Changes of the annex are stored in the "Settings" of the active project. The local annex is stored in the "Output of Device Data" command. To modify the local annex press the "Change Annex" button. See (The Annex for Documentation) for details. Title Most reports display a title on top of each page. The reference "Title" defines the contents of the header. Filter/Annex

Figure 17.2.4: Filter/Annex page

If one wants to report elements without defining a set of objects "Use Selection" on the "Device Data" page must not be checked. The objects in the list "Selected Objects" will be filtered out of the active projects/grids and reported. "Available Objects" shows a list of elements which can be add to the "Selected Objects" list. The list in "Available Objects" depends on the "Elements" radio button. Elements in the left list are moved to the right by double-clicking them. The text in the "Annex" input field will be set as default annex for the selected class. The Annex for Documentation

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CHAPTER 17. REPORTING AND VISUALIZING RESULTS The "Annex for Documentation" stores the annex for the documentation of results. The annex number and the page number for the first page are unique for each class.

Figure 17.2.5: The annex dialogue

Objects This column shows the different classes with their title. Annex This column stores the annex number shown in the Annex field of the report. First Page This column defines the start page for the class in the report. The first page number depends on the class of the first element output in your report. The page number of its class is the page number of the first page.

17.2.3

Output of Results

The command ComSh ("Output of Results" ) is used to produce an output of calculation results. The output can be used in reports or may help in interpreting the results, as shown in Figure 17.2.6. To generate a report with input data use the ComDocu command, see Section 17.2.2 (Output of Device Data). Several different reports, depending on the actual calculation, can be created. The radio button on the upper left displays the different reports possible for the active calculation (Figure 17.2.6 shows a loadflow). Some reports may be inactive, depending on the object(s) chosen for output. In Figure 17.2.6, a Complete System Report was selected for output. In the second page ( ) the "Used Format” displays the format(s) used for the report. Some reports are a set of different outputs. For these reports more than one form is shown. If the form is modified it will be stored automatically in the "Settings" folder of the active project. The changed form does not influence the reports of other projects. If "Use Selection" is active a set of objects (selection) or a single object must be chosen. The report is generated only for these elements. All relevant objects are used if "Use Selection" is not selected. The relevant objects depend on the chosen report. Most reports display a title on top of each page. The reference "Title" defines the contents of the header. For some reports additional settings are required. These settings depend on the chosen report, the selected objects for output and the calculation processed before. The calculation (left top) and the used 252

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17.2. RESULTS, GRAPHS AND DOCUMENTATION format(s) (right top) are always shown.

Figure 17.2.6: Output of Results dialogue after a Load Flow calculation

17.2.4

Result Objects

The result object (ElmRes, ) is used by the PowerFactory program to store tables of results. The typical use of a result object is in writing specific variables during a transient simulation, or during a data acquisition measurement. Result objects are also used in DPL scripts, in reliability calculations, for harmonic analysis, etc. An example of the result object dialogue is depicted in Figure 17.2.7.

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Figure 17.2.7: The result object

The result object shows the following fields: Name the name of the result object File path is the path where the result file is saved inside the data base Last Modification date when the result file was changed the last time Default for the default use Info information about the currently stored data including: the time interval the average time step the number of points in time the number of variables the size of the database result-file Trigger-Times trigger times (in case of a Triggered default use) The Clear Data button will clear all result data. Note: Clearing the data will delete the result-file and will reset the database ID. This will destroy all calculated or measured data in the result file. It will not be possible to restore the data.

The default type settings are used for two purposes: 1. Creating a new result object and setting the default type to Harmonics, for instance, will cause the harmonics command dialogue to use this result object by default. 2. Setting the Default type to Triggered will cause the calculation module to copy and temporarily store signals in that copied result object, every time a Trigger Event becomes active. The Triggered default type enables the trigger time fields.

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17.2. RESULTS, GRAPHS AND DOCUMENTATION When the Output Protocol is pressed, all events that happened during the simulation, recorded by the result object, will be written again into the output window. So one can check what events took place during the last simulation. The contents of a result object are determined by one or more monitor Variable Selection (IntMon) objects. These monitor objects can be edited by pressing the Variables button. This will show the list of monitor sets currently in use by the result object. Selecting a set of result variables, using monitor objects is necessary because otherwise all available variables would have to be stored, which is practically impossible. Exporting Results The stored results for the monitored result variables can be exported by pressing the Export button in the result object. This will activate the "ASCII Results Export" command ComRes and will pop up the ASCII-results export dialogue, which allows for exporting to the output window, to the windows clipboard, to a file or to other export formats. This command is the same command for exporting curve data form a VI plot. This is described further in Export of Curve Data. In this dialogue the individual step size can also be set, the columns of the result file and the header for the export as can be seen from Figure 17.2.8.

Figure 17.2.8: Command dialogue of the ASCII result export

This function will export the data from the displayed curve with the given time range as ASCII text to the following programs/files: • Output Window • Windows Clipboard • Measurement File (ElmFile) • ComTrade DIgSILENT PowerFactory 15, User Manual

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CHAPTER 17. REPORTING AND VISUALIZING RESULTS • Textfile • PSSPLT Version 2.0 • Comma Separated Values (*.csv) The export command allows for exporting an interval of results only and to export every n-th result. Additionally, in the Advanced Options page, a User defined interval for the time/x-scale can be set as the minimum and maximum value of the first recorded variable (in time domain simulations this is of course the time). By default, the option “Export all variables" is selected, which mean that all the results for all monitored variables are exported. But also a selection of variables can be made by selecting the option “Export only selected variables".

17.3

Comparisons Between Calculations

At many stages in the development of a power system design, the differences between certain settings or design options become of interest. For a single calculation, the ’absolute’ results are shown in the single line graphics. The variables that are shown may be specified by the user by altering the result-box definitions. When pressing the Comparing of Results on/off button ( ), the results of the first calculation are ’frozen’. All subsequent calculations will then show their results as deviations from the first calculation made. The subsequent calculation results are stored together with the first result. This allows the user to re-arrange the comparisons as desired by pressing the icon (see the next Section). The differences between cases are coloured according to the severity of the deviation, making it possible to recognize the differences between calculation cases very easily. The colouring and severity ranges may be set in the Edit Comparing of Results... menu option, found by pressing (see the next section). A comparison between cases is made as follows: • Calculate the first case by activating a certain calculation case and, for example, calculating a load-flow. • Press the icon on the main toolbar. This will store the base case results and prepares to store the results of forthcoming calculations. • If relative results are also required for a particular calculation report, in a formatted report, that report has to be generated for the first case by pressing the icon on the main toolbar and selecting the required report. This step is necessary to let the comparison manager know which parameters are to be compared. • Change the power system or a calculation setting to create the next case. Permitted alterations include opening/closing switches, altering load settings or any other component parameter, changing calculation cases, adding or deleting elements, changing the active variations of scenario, etc. • Repeat the calculations as performed for the first case. • The result boxes in the single line graphic will now show the percentage change as compared to the first case. If the calculation report, as generated for the first case, is generated again, it will also show relative results. • Make and calculate the other cases. After each calculation, the comparison to the first case is shown.

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17.3.1

Editing a Set Of Comparison Cases

The set of calculated comparisons may be edited to select the cases which are to be compared to each icon on the main toolbar is pressed, the Compare other or to set the colouring mode. When the dialogue will open. See Figure 17.3.1.

Figure 17.3.1: The Compare dialogue

With the Compare dialogue, the two cases which are to be compared can be selected. Furthermore, a list of colours may be set which is then used to colour the results displayed in the result boxes, according to certain levels of percentage change.

17.3.2

Update Database

In PowerFactory input (data that has been entered by the user) and output (parameters that have been calculated) data is kept separate. Output data, such as the new tap positions following an automatic tap adjustment calculation, does not overwrite the settings that the user originally entered, unless the user icon on the main toolbar. specifically commands this, using the Note: The corresponding input parameters of the database will be overwritten by the calculated values.

Updating the database may be performed for: • Scaling factor of loads • Transformer taps • Capacitive Steps of Shunts/Filter • P,Q of Loads DIgSILENT PowerFactory 15, User Manual

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CHAPTER 17. REPORTING AND VISUALIZING RESULTS • P,Q of Asynchronous machines • P,Q,V of Synchronous machines and Static Generators Example: A load-flow is calculated with the options "Automatic Tap Adjust of Transformers" and "Automatic Shunt Adjustment" enabled. The calculated tap and shunt positions may be seen in the single line diagram, but it will be noticed that the input data parameter in the element data dialogue is as originally entered. is clicked, and the input parameters are now overwritten by the calculated values found If the icon on the single line diagram.

17.4

Variable Selection

Variable Selection (IntMon objects) are used to select and monitor variables associated with objects of the data model in order to store results. The selection of a variable selection, determines the variables to be recorded during a simulation run of the variables to be displayed by a "Flexible Page Selector". Before a calculation is performed or after initial conditions of a time domain simulation have been calculated, the user can define variable selection monitors from the single line graphic. To do this, perform the following steps: • Right click on the target network component. • Select Define → Variable Selection (SIM) from the context sensitive menu. • A data browser listing all the results objects defined in the active study case should appear. Double click on a target result object to select it. If no result objects have been defined, PowerFactory will generate a default one, called “All calculations". Variable Selection Monitors can also be created directly in the target results object using the Contents button (of the Results object). This will pop up a browser with all the variable selections that have already been defined. To define a new variable selection, the icon in the browser can be pressed.

17.4.1

The Variable Selection Monitor Dialogue

An example of the variable selection object is shown in Figure 17.4.1. Here the variable selection for the load called Load C, which is found in a grid called Nine_Bus of the active project is shown (red circle). In this case a RMS simulation (green circle) is to be performed and the total active and the reactive power flowing to the load are going to be monitored (blue circle).

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Figure 17.4.1: Example of a variable selection dialogue

In the Variable Selection Monitor dialogue the following fields can be seen: Object Is the selected object (normally a network component), whose variables are going to be monitored. Class Name If no object has been selected the "Class Name" field becomes active. This is normally used for more advanced studies and need not be explained further here. Display Values during simulation in output window (...) By checking this box and selecting the option ’Display results variables in output window’ in the simulation command, the values calculated for the selected variables during a simulation will be displayed in the output window. Filter for As mentioned previously, there is a large number of variables that may be observed in PowerFactory. To be able to find and select these they are sorted into sets. A series of filters allows the user to sort through the sets. Further information about the selection of variable is given in the subsection Searching the Variables to Monitor. Page Tab The first sorting of the variables is by calculation function (load-flow, short-circuit, etc.). In the example of Figure 17.4.1, the RMS-Simulation page has been automatically selected, as a prior RMS calculation was performed. Available Variables All of the variables that are available for display are listed here (as sorted by the filter). DIgSILENT PowerFactory 15, User Manual

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CHAPTER 17. REPORTING AND VISUALIZING RESULTS Selected Variables The selected variables are shown here. Variables are placed here by clicking on them on the "Available Variables" side, by selecting their checkbox, or by selecting them and then pressing the ( ) button. The user can remove variables from the Selected Variables area by doubleclicking on them. Display All If this box is checked then all of the selected variables are shown in the ’Selected Variables’ area. If it is not checked then the filter will also apply to the "Selected Variables" area and only those selected variables in the filtered set will be shown. The following buttons are available on the right of the dialogue: • Balanced/Unbalanced: Depending on the type of calculation to be monitored (balanced or unbalanced), the user can toggle between balanced and unbalanced variable selections. • Print Values: Prints the current values for all the selected variables to the output window. • Variable List: Prints a list of all available variables to the output window. • Variable List (Page): Prints a list of available variables for the current page (e.g. Basic Data) to the output window. The second tab of the Variable Selection Monitor Dialogue, goes to the Editor, where variables can be manually input- for advanced use.

17.4.2

Searching the Variables to Monitor

The first sorting of the variables is by calculation function (load-flow, short-circuit, etc.). Within these sets variables are sorted into sub-sets. The user can select the desired subset by means of the drop down menu on the Variable Selection field. Following a description of the available subsets: Currents, Voltages and Powers Almost self explanatory- these are the outputs as calculated by a calculation function. The variable is preceded by "m:" (representing ’monitored’ or ’measured’) as in "m:P:bus1" for the active power drawn by the load. The user may select one set for branches and one set for the nodes, which then is used for each node the edge is connected to. Bus Results Variables for the bus/es that the element is connected to (usually preceded by "n:" for ’node’). A branch element (having only one connection to a bus) will obviously only have results for "Bus1." An edge element (two connections, as in a line for example) will have "Bus1" or "Bus2". This means that the results of objects connected to the object whose variable list is compiled can be accessed. An example of this variable is the open end voltage at a line end. See the subsection Selecting the Bus to be Monitored for further information. Signals Variables that can be used as interface between user defined and/or PowerFactory models (inputs and outputs). They are preceded by "s:". These should be used when creating a controller or in a DPL script. These variables are accessible whilst an iteration is being calculated, whereas the other variables sets are calculated following an iteration. Calculation Parameter 260

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17.4. VARIABLE SELECTION Variables that are derived from the primary calculations (i.e. currents, loading, power, losses, etc.), from input data (i.e. the absolute impedance of a line, derived from impedance/ km * line length), or that have been transformed from input data to a format useful for calculation (actual to per unit), or that are required for such transformation (e.g. nominal power). The parameters that actually are available depend on the object type. Calculation parameters are preceded by a "c:". Element Parameter Input Parameters that belong directly to the object selected (preceded by "e:"). Type Parameter Input Parameters from the corresponding type object that are linked to the element object under consideration; for example, the current rating of a line type that a line element is using. Reference Parameter These are variables from objects that are linked or connected to the object under consideration (preceded by "r:"). For example, a line element may be part of a line coupling and the reference parameter will allow us to display the name of the coupling element. The use of reference parameters is explained following examples. For general use it is sufficient to simply select the variables required and transfer them to the selected variables column. To find a particular variable requires some knowledge of where the variables are stored in the object under consideration.

17.4.3

Examples of Variable Selection

In this subsection an examples for the use of the above described sets are given. The procedures described below always apply, regardless of which is the final use of the variable selection monitor, i.e. Flexible Data Page, Results Box, Plots, etc. Suppose that a two winding transformer called T1 is to be monitored. The following variables are going to be selected: • Type name • Tap setting • Nominal and calculated voltages at the HV node. The name of the transformer type is entered in the type data so we select the type parameters (as the Variable Selection) in the filter - the name is also entered on the basic data page so we should select the Basic Data page, and the type name parameter is "loc_name" (Figure 17.4.2). Notice that the focus object for the variable selection object is a transformer.

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Figure 17.4.2: Finding the type name

The tap setting will be found in the element data and the parameter is located on the load-flow page (this information is gained as the user becomes more familiar with PowerFactory and recalls where the data was entered; such recollection directs the user to the correct variable sub-set). The variables seen in the selected Variables column should now be: • t:loc_name • e:nntap To be able to see the variables for the HV bus we use the reference parameters. The reference parameters work like a ’refer to’ command. In Figure 17.4.3 this is illustrated schematically. We have started by creating a variable selection for the object ’T1’ which is an element object. Using the reference parameter we will refer to the object that the LV side of the transformer is connected to, which is the cubicle ’Cub_2’. Since the nominal and calculated voltages of the node are located in the node object itself we will next need to refer to this node object ’LV’.

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Figure 17.4.3: Referring to with reference parameters

Step by step, the process will be as follows: We first need to refer to or ’jump to’ the cubicle. If we picture the input dialogue for the transformer element we recall that the connections for the HV and LV sides are listed on the basic data page, so this is where we will logically find the ’link’ to the connected object (the cubicle). In Figure 17.4.4 we can see that this selection has been made (Basic Data page). We also notice that the object that is presently the focus is the transformer element as the object. To affect the jump to the cubicle we choose the reference parameter set, and then select the object that we want to jump to, the cubicle connected to the HV side in the Available Variables list.

Figure 17.4.4: Selecting the parameter to be displayed

Double-clicking on this jumps us to another variable selection object whose focus object is the cubicle that the LV side of the transformer is connected to. It is not immediately obvious that the jump has occurred as the new Variable Selection object appears directly on top of the original one. If grabbing DIgSILENT PowerFactory 15, User Manual

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CHAPTER 17. REPORTING AND VISUALIZING RESULTS the one that appears before you and drag it to one side it will become more obvious (you can also see this by noting that the name in the "Object" field has changed), and will look as shown in Figure 17.4.5. The second jump must now be affected - to the node that the cubicle is connected to. In a logical fashion this ’connectivity’ is also found on the Basic Data page. Figure 17.4.6 shows the result of these jumps in PowerFactory. Lastly, the parameter required must be selected.

Figure 17.4.5: Jumping to the cubicle using the reference parameter

The parameter we wish to display is the nominal voltage of the connected node. This will be found on the Basic Data page and we must choose the element parameter set to find the parameter, as shown in Figure 17.4.6. The parameter is called • uknom

kV

Nominal Voltage: Line-line

At this point we could also add the calculated voltage for the node. This will be found under "Currents, Voltages and Powers" on the Load Flow page. After having clicked Ok until you are back at the original variable selection object you will see that these referenced variables have been added as: • r:buslv:r:cBusBar:e:uknom • r:buslv:r:cBusBar:m:U Which can be read as → jump to the LV bus→ jump to the connected node→ display the selected variables. Once the user is more familiar with this nomenclature this jump may be typed in directly to the variable selection object. Note: In this particular example we have used a ’long’ method to show to the node variables for illustration purposes. Typically, however, a user wishes to display calculated variables such as the 264

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17.4. VARIABLE SELECTION voltage at the end of a line where the breaker at that end is open. In this case PowerFactory has a special ’shortcut’ set - the "Bus Results".

Figure 17.4.6: Jumping to the node and selecting the parameter

These bus results can only be seen in the calculation function tabs and they are drawn from an internal node that is not displayed on the single line graphic. An illustration of this node and its relationship to the cubicle is shown in Figure 17.4.7.

Figure 17.4.7: Internal node

17.4.4

Selecting the Bus to be Monitored

When selecting variables from the Currents, Voltages and Powers set, the user will notice that there is a filter called Bus Name. This is used to determine which side of an edge element is to be considered.

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CHAPTER 17. REPORTING AND VISUALIZING RESULTS To maintain standard nomenclature the objects at the ends of a line element are named Terminal i or Terminal j and HVside or LVside in the case of a transformer. The ends of an edge element are named bus1 or bus2 and bushv or buslv respectively (a three winding transformer will also have busmv ). These ends are matched to the i and j sides so that i → bus1 or bushv and j → bus2 or buslv. Thus, when choosing variables from the flexible page manager the user should specify which side of the edge element the variables are to be taken from. Note that bus1, bus2, bushv, buslv are not references to the connected node, they are in fact the ends of the edge element. When a variable is selected for display from the single line graphic the user will notice a further classification, that of _LOCALBUS. This classification merely indicates the end of the edge element and describes internally which side of the edge element the result box should access its variables from. That is the bus local to that end.

17.5

Virtual Instruments

A virtual instrument is basically a tool for displaying calculated results. The most common use of a VI is to look at the results of a time-domain simulation like an EMT or RMS simulation, by defining one or more plotted curves showing the variables changing with time. But there are various other applications of virtual instruments, for example to graphically display voltage profiles, FFT plots or the results of a harmonic analysis. This could be in the form of a bar graph, a plotted curve, single displayed variables, tables of values, etc. To visualize results from a calculation, two different parts are important: Virtual Instrument Panel The Virtual Instrument Panel is basically a page in the active graphics board, where different plots or graphs are stored and displayed. The basic information about the included virtual instruments is stored here. Virtual Instruments Virtual Instruments (VIs) are shown on Virtual Instrument Panels and display the results of one or more variables or parameters. Multiple VIs can be defined for any one Virtual Instruments Panel and individual VIs can be set up as required by the variable(s) displayed. All signals, parameters, variables or other magnitudes from PowerFactory can be shown in a Virtual Instrument. The variables are normally floating point numbers, but there is also the possibility to show discrete variables as well as binary numbers, for example an "out of service" flag or the switching operation of a circuit-breaker. There are various designs of Virtual Instruments available in PowerFactory . These Virtual Instruments can be divided into several groups, which are described in the subsequent sections of this chapter: Plots are the ’basic’ diagrams used to show variables. Variables can be plotted against either a time axis or an axis defined by another variable. PowerFactory plots include the following: • Subplots (VisPlot) • Subplots with two y-axis (VisPlot2) • X-Y plots (VisXyplot) • FFT plots (VisFft) Bar Diagrams are similar to Plots. In Bar Diagrams the results are not shown as a line, but as single bars for each data point.

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17.5. VIRTUAL INSTRUMENTS Vector Diagrams show different variables - like voltage, current or power - in a vector diagram using polar or cartesian coordinates. Meter Panels display variables or parameters using a mimic of a physical display or provide a means of user interaction via a button or switch. Meter Panels include: • digital display • horizontal scale of a meter • vertical scale of a meter • measurement VI • interactive button/switch Curve Inputs are used to convert graphical information (graphs or curves) into a set of data by scanning and sampling the data points. Bitmaps can be inserted as a remark or to provide further information. In addition to the above options there are further types of virtual instruments for specific purposes. For example, the time-overcurrent plot or the time distance diagram is available for protection studies. Study specific plots are not described in this chapter but rather directly in the section of the manual dealing with the individual calculation method. The following list briefly describes some other virtual instrument types: VIs for Protection Studies Time-Overcurrent Plot When studying overcurrent relays the tripping characteristic is often displayed by plotting the magnitude of the current on the x-axis and the resulting relay tripping time on the y-axis. In PowerFactory, the characteristic curves of power system elements which are to be protected can also be inserted into the Time-Overcurrent Plot. See Chapter 39: Protection and Section 39.4 (Time-Overcurrent Plot) for further details. R-X Plot For distance protection relays, the tripping characteristic of one or more relays can be visualized in a R-X diagram. PowerFactory includes a R-X Plot for showing the characteristics of distance relays. PowerFactory also includes a feature to define the impedance of adjacent elements graphically inside the R-X diagram. See Section 39.6 (The impedance plot) for further details. Time-Distance Diagram For studying the selectivity of distance protection, the Time-Distance Diagram is often used. PowerFactory provides a convenient method to automatically show all distance relays in a specified protection path in one Time-Distance Diagram. See Section 39.7 (The time-distance plot) for further details. Feeder Definitions Voltage Profile The Voltage Profile shows the voltage profile of a complete subsystem belonging to a defined feeder in the power system. The voltage profile can be plotted against either the feeder distance or the node number. See Chapter 13 (Grouping Objects) for further details. Schematic Path The Schematic Path plot allows a meshed or radial network to be shown in a brief schematic. Instead of displaying result boxes, visual information like colours for overloading or voltage are selected by the user and displayed. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 17. REPORTING AND VISUALIZING RESULTS Harmonics Waveform Plot A Waveform Plot can be used to show the magnitude and phase angle of voltages and currents at harmonic frequencies. With this diagram a variable like the voltage or current, which is defined in a harmonic source e.g. a power electronic device or a load, can easily be shown as a time dependent variable. So the real shape of the voltage can be seen and analysed. For a more detailed description see 17.5.7: The Waveform Plot. Modal Analysis Eigenvalue Plot The Eigenvalue Plot (Viseigen) displays the eigenvalues calculated in the modal analysis (Chapter 27: Modal Analysis / Eigenvalue Calculation). Double-clicking any of the displayed eigenvalues, pops-up an informative dialogue, where the oscillation parameters and the coordinates in complex and polar representation are given. For a full description of the eigenvalue plot see Section 27.4.2 (Viewing Modal Analysis Results using the built-in Plots). Mode Bar Plot The Mode Bar Plot (VisModbar ) displays the participation factors of the system generators in a selected mode. Full description of the Mode bar Plot is given in Section 27.4.2 (Viewing Modal Analysis Results using the built-in Plots). Mode Phasor Plot The Mode Phasor Plot (VisModephasor ) displays the same information of the Mode Bar Plot but in a phasor diagram. For further information see Section 27.4.2 (Viewing Modal Analysis Results using the built-in Plots). The tools available for modifying virtual instruments, such as labels and constants, can be applied equally to most virtual instrument types.

17.5.1

Virtual Instrument Panels

Virtual instruments are created and edited on a Virtual Instruments Panel (SetViPage) which is one of the possible types of pages on a Graphics Board. Other page types are single line graphics and block diagram or frame graphics. A new virtual instrument panel can be created by • selecting the File → New option on the main menu and subsequently selecting a "Virtual Instrument Page" in the ComNew. This will create a new page in the "Graphics Board" of the currently active study case. icon on the graphics board’s toolbar and selecting "Virtual • selecting the Insert New Graphic Instrument Panel". This will also create a new VI panel in the current graphics board. All virtual instrument panels are stored in graphics boards. A graphic board holds default settings for icon is clicked or the Edit Actual Virtual Instrument Panel option is plots and other diagrams. The selected from the context sensitive menu to edit the dialogue. Note: If a new virtual instrument panel is created, while there is no Graphics Board opened already, a new Graphics Board in will be added to the current study case.

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17.5. VIRTUAL INSTRUMENTS The dialogue is build of several pages. These are x-Axis holds the default x-Axis for plots without local axis stored in pages without local axis. Advanced holds the advanced settings like the arrangements of the plots or their specific style. Results stores a reference to the default results object used by the plots. Once a VI panel has been created, the "Append new VI(s)" icon can be clicked or the option Create VI → . . . from the context menu of the SetVipage can be selected to add new virtual instruments to the VI panel. Virtual instrument panels usually set the size and position of new virtual instruments like plots automatically. But it is possible to turn on user defined moving and resizing of the plots. In this mode the plots and icons are used to tile the Virtual Instruments can be moved or resized by the user. Also the horizontal or to arrange the VIs automatically. A ViPage uses a predefined style which set line-styles, line-width, fonts and other graphical settings. User defined styles can be created and selected. A different style can be selected on each VI panel of a Graphics Boards. These different options are described in the following sections. Editing the Virtual Instrument Panel dialogue There are several ways to access the graphics board dialogue from PowerFactory • When the panel is empty one can access the dialogue by simply double-clicking the empty VI panel or an empty area on the panel. • Right-click the background of the VI panel besides the shown plots and choose Edit actual Virtual Instrument Panel from the context menu. • The simplest way to edit the dialogue is to click the

icon.

The icon is clicked or the Edit Actual Virtual Instrument Panel option is selected from the context sensitive menu to edit the dialogue. The dialogue is split into three different pages named: • x-Axis holds the settings for x-Axis of plots and Waveform Plots. • Advanced holds graphical settings like Style and Background. • Results contains the reference to the default results object for plots. Automatic Scale Buttons The buttons or are clicked to scale the x-axis respectively the y-axis of all plots on the virtual instrument panel automatically. Plots on other panels in the same graphics board are unchanged if their axes are local. The buttons are inactive, if there are no plots shown at all or if the x or y axes can not be scaled automatically. That applies e.g. for bar-diagrams showing the distortion after a harmonics load-flow calculation, where the x-axis is given by the harmonic frequencies. Different types of plots, like the subplot and the waveform plot, can be scaled simultaneously. With the button Zoom X-Axis a certain range of the x-axis or of several x-axes can be zoomed easily. Click on the icon to activate the function, then click on a plot, hold the right mouse button and ’drag’ the mouse to the right or to the left to mark the desired range on the x-axis. If the mouse button is released, PowerFactory will then show the marked x ranged zoomed. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 17. REPORTING AND VISUALIZING RESULTS Automatic Arrangement of VIs Virtual instrument panels usually set the size and position of new virtual instruments like plots automatically. Then the VIs can not be resized or moved. So the position of these VIs is set automatically and their size remains unchanged. There are two different modes for automatically arranging the VIs. The user can choose to arrange the VIs using either • Arrange Subplots on Top of Each Other with the icon • Arrange Subplots automatically with the icon

or

.

The modes can easily be changed by pressing the one or the other button. In addition the position of VIs can easily be exchanged. Thereto mark the VI by clicking it. Then ’drag’ the VI onto another plot. Thus the position of the VIs will be exchanged. Note: This option of exchanging the plots by dragging is only possible, when one of the arrangement buttons are active. If you deactivate both buttons by unselecting them in the toolbar, the plots can freely be moved by dragging them on the panel. See also Moving and Resizing.

Another way to rearrange the VIs is to open the dialogue of the VI panel by pressing the icon and then use the Arrangement options on the "Advanced" page. Here the option User defined can be activated. So the VIs will no longer be arranged automatically but can be resized and moved inside the panel. So the user is free to arrange the VIs ’ad libitum’. This mode is also activated by disabling the selected icon or . Moving and Resizing Moving and resizing of VIs in the standard virtual instrument panels is turned off. Both can be activated by deactivating the auto-arrangement modes by disabling then currently active icon or . Also the option User defined can be activated on the Advanced page of the edit dialogue of the VI panel. A VI is clicked to mark it. The VI is ’dragged’ inside the panel by clicking it with the mouse button pressed. Then the VI can be move across the panel. The mouse is released to set the new position. Note: Please note that some VIs can not be resized at all because their size is set automatically. This applies e.g. for the bitmap VI with the option Adapt Size of VI to Size of Bitmap enabled.

Page Format The page format is modified using the in the toolbar of the graphics board. VI panels use the page format set in the graphics board. In addition a local page format can be created for each VI panel. The option Create local Page Format is selected in the context sensitive menu to create a local page format. The VI panel now uses a local page format independent of the page format set in the graphics board. Set default Page Format is selected in the context sensitive menu to reset the local page format. The VI panel now uses the default format of the graphics board again. Editing Variables of Plots The icon is clicked to open the Edit Plots on Page dialogue for defining curves of several plots. If the variables of only one subplot are to be changed, it is suggested to edit the dialogue of the plot itself by double-clicking it. This procedure is more convenient. This dialogue gives a very good overview over the diagrams on the VI panel and the variables, axis and curve styles. Figure 17.5.1 shows an example of the dialogue. 270

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Figure 17.5.1: Editing all plots on the page

Each line of the table named Curves defines a variable shown on the panel. The variables definition applies to the plot shown in the first column. When the dialogue is opened the plots are sorted from left to right and from top to bottom and are numbered accordingly. All data and settings of each variable is displayed in the table, and the columns are used exactly like the columns in the table of a plot. To move a variable from one plot to another, simply change the Plot Nr. of the variable to move. In this table not only subplots (VisPlot) are shown but also plots with two y-axis (VisPlot2) can be modified. Here additionally in the column y the y-axis can be defined to which the variable is related. In Figure 17.5.1 this can be seen in the to last rows of the table. Here both variables are shown in one plot number 7 with two different axis. If the number in this row is grey, only one y-axis is available in this plot. Like in most tables new rows can be add. Default File for Page is a reference to the results element of the virtual instrument panel. The Filter... button opens the filter dialogue. The selected filter will be applied to all plots on the current virtual instrument panel. Default Result File for Page is a reference to the default results element of the virtual instrument panel. This is exactly the same setting like the one displayed on the Results page of the dialogue box of the virtual instrument panel. Title Block All virtual instrument panels in a Graphics Board show the same title by default. The only difference of the title blocks on the VI-Panels are the panel name and the page number which are unique for each panel. To create a local title for a VI-Panel simply right-click on the title and select Create local Title from the context sensitive menu. icon in the toolbar is clicked to show or hide the title block. The Like in the single line graphics the title can be defined or changed by double-clicking on them or use the icon to modify the title text. For details about the settings of the title object refer to Chapter 9: Network Graphics. Results Some VIs like the most frequently used class "subplot" show curves stored in one ore more result objects (ElmRes). The curves are selected in a table where the result element, the element and a variable have to be selected. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 17. REPORTING AND VISUALIZING RESULTS The result column of VIs needs not to be set for most calculations. The VI itself will look for the results element to display automatically. The default results element is either: 1. Results reference on page Results of the VI Panel accessed by pressing the

icon.

2. If 1. is empty the Results reference on the Results page of the Graphics Board will be used by pressing the icon. 3. If both (1. and 2.) are not empty, the results element used for the last calculation will be applied. If there is no calculation the appropriate results element in the study case will be used (if any). Background The default background of virtual instrument panels is empty. The background settings for the panel can be found in the frame Background on the "Advanced” page of the virtual instrument panel dialogue. The Filename defines the background file, which can be either a Windows Metafile (*.wmf), a Bitmap (*.bmp) or a AutoCad DXF file. If the selected file does not exist, or if the filename is not set the background remains empty. VIs can be transparent or opaque. Graphics are transparent must be activated to make all graphics transparent. If an opaque graphic fills the complete panel area the background will be invisible. The Context Sensitive Menu The options in the context sensitive menu of the VI panel may vary depending on the cursor and the settings of the panel. The options are listed below: • Edit Actual Virtual Instrument Panel opens the virtual instrument panel dialogue. • Create local Page Format creates a page format for the current panel. • Paste Text inserts text from the from the clipboard into the panel. • A VI can be selected from the list shown in the Create VI → . . . option to create a new VI on the panel. • Style → Select Style is clicked to select a style for the panel. • Style → Create new Style is selected to create a new style for the panel. • Style → Edit Style of clicked Element is selected to modify the style of the selected element only. • Select All → is selected to mark all VIs. • Export Results. . . exports the shown result into e.g. the output window, a ASCII file, a Comtrade file or the clipboard. Creating Virtual Instruments icon . A small dialogue will pop up, where New VIs can easily be created with the Append New VI(s) the class of VI can be selected from the available Object and the number of VIs to be added to the current VI panel. Another way to create VIs is to select the option Create VI → . . . from the context menu of the SetVipage. Then a class of virtual instrument can be selected to be added to the current VI panel. The Default Styles Each virtual instrument panel uses a style where line-widths, fonts, brushes and other graphical settings are defined. There are six predefined styles available in DIgSILENT PowerFactory , which are:

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17.5. VIRTUAL INSTRUMENTS • Default - Standard English Text and Symbols • Gr Default - Greek Symbols • Tr Default - Turkish Symbols • Paper • Gr Paper • Tr Paper The "Default" styles uses smaller line-widths and smaller fonts than the "Paper" styles. It was designed to get nice printouts. The paper style was designed for reports and papers where meta-files are included in text-programs. In addition to the layout the styles hold predefined VIs. There are several ways to select a predefined or user-defined style for the current virtual instrument panel. The easiest way to change the style is using the toolbar. • The list-box in the toolbar is clicked and an available style is selected. • A style is selected from the Style → Select Style→ . . . in the context sensitive menu of the VI panel. • A style is selected in the VI-Style list-box on the "Advanced" page of the SetVipage dialogue. The user-defined styles are described in detail in Section 17.5.11 later in this chapter.

17.5.2

Plots

Plots are the most used diagrams to show parameters, states, signals or variables depending on either time or on another variable. The following plots are available in PowerFactory : • SubPlot (VisPlot) • SubPlot (2y) with two y-axes (VisPlot2) • X-Y plot (VisXyplot) • FFT plots (VisFft) The Subplot SubPlots are the ’basic’ diagrams and are typically used to display one or more plotted curves from the results of an EMT or RMS simulation. icon and selecting A new subplot is created on the current Virtual Instrument panel by pressing the a Subplot (VisPlot) from the pull down list. More than one subplot may be created at once by setting the Number of VI(s). The new empty subplots appear with standard settings, as shown in Figure 17.5.2.

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Figure 17.5.2: Creating a new SubPlot (VisPlot)

To edit the subplot either: • right-click on the subplot, and select the Edit option from the context sensitive menu; or • double-click on the subplot. Editing Subplots The edit dialogue of a subplot, as shown in Figure 17.5.3 has pages for the y-axis and x-axis of the individual subplot as well as an additional Advanced page for auxiliary settings. The y-axis page is normally used to set the curves in the subplot, while the x-axis normally shows time (by default).

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Figure 17.5.3: The SubPlot edit dialogue

The subplot edit dialogue has the following features: Scale The y-axis may be defined for more than one subplot at the same time, or, and by default, may be defined as a "local Axis" format. When the option Use local Axis is disabled, a reference to the used ’global’ axis type is shown and can be edited by pressing the . Automatic The color, line style, and line width of all new curves in the subplot will be set automatically when the corresponding option is enabled. The Set now button will apply automatic line formats all existing curves again. Shown Results This is a reference to the currently active result file (ElmRes). This object will be used, if no result file is specified in the Curves definition table. Curves The definition table for the curves is used to specify the result file (optional), object and parameter for each of the curves as well as their representation. User Defined Signals DIgSILENT PowerFactory 15, User Manual

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CHAPTER 17. REPORTING AND VISUALIZING RESULTS User defined curves can be created from calculated results using DSL compatible arithmetic equations. The available options are described in more detail below. Setting the X-Axis The x-axes often needs to be synchronized for all subplots or for all subplots on one VI panel, for instance to show the same time-scale in all plots. In order to synchronize the x-axes without losing the freedom to manually set each subplot, a hierarchy of x-axes is used in the Graphics Board: • The Graphics Board contains the basic x-axis definition. This definition is used by default by each new subplot. • A VI panel, however, may define a local x-axis definition, which will then be the default for each new subplot created on that panel. • The subplot thus uses the Graphics Board or the panel SetViPage definition by default, but may also use a local x-axis definition. Note: If you change the settings of the x-axis, which uses the definition stored in the graphics board, all x-axis are changed using the same definition in the whole project. These are also affected, if the x-axis is automatically scaled or zoomed.

The following list describes how to edit the definition of the different x-axes: • To edit the graphics board definition, either right click on the Virtual Instrument and select Edit or double-click on the Virtual Instrument. Next click on the x-Axis page of the edit dialogue of the plot and select the option Graphics Board under ’Scale’, ’Axis’. The dialogue for changing the xaxis definition for the complete graphics board can be then accessed via the Used Axis selection. Another way to modify the graphics board definition is to click the icon for the graphics board dialogue and then go to the x-Axis page. • Similar to the graphics board definition, to edit the virtual instrument panel specific x-axis, either right click on the Virtual Instrument and select Edit or double-click on the Virtual Instrument. Next click on the x-Axis page of the edit dialogue of the plot and select the option Page under ’Scale’, ’Axis’. The dialogue for changing the x-axis definition for the virtual instrument panel can be then accessed via the Used Axis selection. This will display the dialogue of the of the VI panel (SetVipage). Another way get to the panel dialogue is by clicking the icon or selecting Edit actual Virtual Instrument Panel from the context menu and then go to the x-Axis page. • The local (virtual instrument) x-axis definition is accessed by selecting the option Local. When Local is selected, the options for specifying the x-axis are shown directly in the edit dialogue. The options available for the x-axis are similar to the one for the y-axis. They are described in the following section. The only difference is in selecting the variable of the axis. Within the x-axis page there are numerous options to choose from for the x-Axis Variable as shown in Figure 17.5.4. The Default value depends on the type of simulation and the result object created during the previous simulation. For time-domain simulations different representations of the time scale are available. For an FFT plot, the x-axis can be scaled using the frequency in Hz or the harmonic order.

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Figure 17.5.4: The variable list available for the x-Axis

The option User defined enables the user to choose any variable for the x-axis, selectable from a result object. In this way an x-y plot can be created. Whilst the VisPlot can be used to create x-y plots, there is also a specific plot type to create an x-y plot: the VisXyplot. The VisXyplot is described in more detail in section VisXyplot. Setting the Y-Axis The y-axes are normally not synchronized across virtual instruments like the x-axis can be, because they all show different parameter values and thus need parameter-specific settings. By default, the Graphics Board’s default plot type is used, but more plot types may be created and used, i.e. plot types for voltages, power, factors, slip factors, etc. By using the same plot type, different plots can be compared more easily, without the risk of misinterpreting a difference in curve amplitude. The y-axis page in the subplot edit dialogue has the option to Use local Axis. Similar to the x-axis, if the Use local Axis checkbox is not ticked, the graphics board y-axis settings are selected. The graphics board y-axis settings can be altered by selecting Type when the Use local Axis checkbox is unticked. The local definitions of an axis (either the x-axis or the y-axis) has three parts: • The axis Limits (minimum and maximum) • The axis Mapping (linear, logarithmic) • Auto scale options • The Adapt Scale settings to adapt the scale to a setpoint.

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CHAPTER 17. REPORTING AND VISUALIZING RESULTS The axis Limits can be set manually, or can be auto scaled via the Scale button. The scale button sets the limits automatically from the curve shape. The options to Auto Scale the plot are: Off Turns any auto scaling function off and will display the results in the range between the given limits. On This option will automatically scale the plot at the end of a simulation. Online This option will automatically scale the plot during the simulation. The x-axis additionally features a Chart option. If ticked a range and a start value can be set. This will set the x-axis to the specified range. During the simulation, only an x-range, set in the options, is shown and will ’wander’ along with the calculation time. The Adapt Scale settings are used to force a tick mark on the axis at a particular value. The tick marks can be forced by setting the Offset value for the y-axis and the Trigger value for the x-axis. Other tick marks will be drawn at ’nice’ distances from this offset. The default value for both x- and y-axis is an active adapt scale with both Trigger and Offset equal to zero. With the default values, the main ticks of both axes start at zero. For the y-axis, to see the deviations from the offset, the Show Deviations from Offset option will draw a second axis on the right, which has its zero baseline at the offset value. The Show Deviations from Offset option is available for the y-axis only. An example of two subplots is given in Figure 17.5.5 where a voltage sag is shown with both an instantaneous and a RMS value curve. The top curve has the Adapt option disabled, and both axes autoscaled.

Figure 17.5.5: Two subplots with different axis definitions

The bottom subplot has a smaller x-axis, to show only the interesting part, and has the Adapt option set on both axes. In Figure 17.5.5, the y-axis has its offset set to the nominal voltage level (11kV) and also shows the deviations from that level in the right vertical axis. From this deviation, it is clear that the RMS voltage initially drops more than 5kV. The x-axis has its offset set to the event time, which in this case is 100ms when a short-circuit was simulated. From the x-axis, it is now directly clear that this short-circuit was cleared after 200ms, at t=300ms. Specifying Curves for Plots

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17.5. VIRTUAL INSTRUMENTS The curves in a subplot must be taken from a result object (ElmRes) or a Calculated result object (IntCalcres). A result object is created by a power system calculation function like the RMS or EMT simulation. The method to create a result object is explained in 17.2.4: Result Objects. The method to create a calculated result object is explained in 17.5.3: Calculated Result Objects. The selection of variables to display on the current plot is done in the y-axis page of the edit dialogue. To view the edit dialogue, double-click on the background of the plot or right-click the plot and select Edit. The curve definition is shown on the Y-Axis page of the edit dialogue as shown in Figure 17.5.6.

Figure 17.5.6: Defining a new curve

Each line in the Curves ’table’ is used to define a variable to plot and the visual representation of the curve. • The first column states the result object from which the data to plot the curve will be read. If it is empty, the standard result file will be used, as defined in the reference to Shown Results in the same dialogue. • The second column states the power system element (here the generator "G1d"), which is selected from the available elements in the result object. • The third column states the actual variable for the curve (here "xspeed"), selected from the variables in the result object, belonging to the selected element. • The next columns specify the style of the individual curve. • With the last two columns the user can normalise (Norm.) the values of the variable to a nominal value (Nom. Value). To select a new result object, element or parameter, double-click the field or right-click the field and select Select Element/Type or Edit from the context sensitive menu. Then select a new entry from the list of possible result objects, resp. elements and parameters that appear. The colour, line style and line width settings are edited in the same way: double-click the cell or rightclick the cell and select Edit. To create a new curve definition line, right-click on the column number (on the far left) (see cursor arrow in Figure 17.5.6) and select Insert Rows or Append (n) Rows. Similarly, to delete a marked curve definition from the list, select Delete Rows. Note: To see changes between two consecutive simulations, the following procedure can be used. First run the initial simulation, the simulation results will be stored inside the defined result object *.ElmRes, which can be found in the active study case. Copy the *.ElmRes object, paste it and rename it e.g. to "old Results". Once this is complete, add the same variable to a plot (so that there are two instances) and select the "old Results" result object for one of them (as shown in Figure 17.5.6). Upon updating the simulation, the old and the new results will both be shown in DIgSILENT PowerFactory 15, User Manual

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To easily specify more than one curve for the same result file and element in one action, select more than one variable at once from the variable list. This will automatically create new entries in the curve definition table for all additionally selected variables. The entered Result File and Element columns are copied automatically. This convenient procedure is shown in Figure 17.5.7 and Figure 17.5.8.

Figure 17.5.7: Defining subplots with minimum effort, step 1

Figure 17.5.8: Defining subplots with minimum effort, step 2

Similarly several elements can be selected and PowerFactory will automatically insert the corresponding number of rows. The variables are set automatically to the one selected in the first row. Some plot types (e.g. VisPlot) have the option to define a ’User Defined Signal’ which allows arithmetic calculation of additional results based on PowerFactory calculated results. The method to create a calculated result is explained in 17.5.3: Calculated Results. The Subplot with two Y-Axes icon and select a A plot with two y-axes can be seen in Figure 17.5.9. To create this plot, press the Subplot(2y)(VisPlot2) from the pull down list. This will add a subplot with two y-axes to the current VI panel.

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Figure 17.5.9: The definition of the second y-axis

To deactivate the additional axis, navigate to the page for the second y-axis and untick the option Use second y-Axis. The X-Y Plot A further type of plot is the x-y plot. This plot shows one variable dependant on a second variable. The two variables can be completely independent from each other and do not have to belong to one element. To create a x-y plot press the icon and then select a X-Y Plot(VisXYPlot) from the pull down list. This will add a new x-y plot to the current VI panel. Figure 17.5.10 shows the edit dialogue of the plot.

Figure 17.5.10: Defining variables for a X-Y plot

On the variables page the variables for the x- and y-axis are specified. Both variables have to be stored in one result file of a simulation. To select variables of two different elements the option Show x-Element in Table has to be activated. The options and the tools for the curves are similar to the ones described in section 17.5.2 (The Subplot). DIgSILENT PowerFactory 15, User Manual

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CHAPTER 17. REPORTING AND VISUALIZING RESULTS On the page Scales of the dialogue, the scales of the two axis can be set automatically or global definitions can be used. On page Time Range the time range can be set to the whole simulation time or alternatively select a specified range to show the results pertaining to a specific time range only. The FFT Plot The FFT plot (VisFft) is similar to the normal subplot (VisPlot) in terms of edit dialogues, with the key difference being the x-Axis scale. The FFT plot does not show signals on a time scale, but rather uses a frequency scale. A time range for the signal can be selected prior to transformation into the frequency domain using the Fast-Fourier Transformation (FFT) algorithm. An FFT will show the harmonic content of the time bounded signal. . Alternatively click on a plotted curve and To create an FFT plot, click on the Append VI(s) icon then select Create FFT Plot from the context sensitive menu. Once selected, the mouse pointer can be ’dragged’ from the selected point on the curve to the left or right to define a time range for the FFT. Hold the mouse still to reveal a quick-help box which shows the range, beginning and end of the curve to be transformed. To set the final range for the FFT, simply click the diagram again. The FFT is then calculated and shown in a new FFT plot. To view the FFT plot edit dialogue, double-click on the FFT plot. The x- and y-axis can be defined on the various dialogue pages similar to the VisPlot. Additional options specific to FFT plots are: Calculate The Calculate option on the page y-Axis modifies the fast-fourier transformation and the time range of the signal the FFT is applied to. The button Synchronize will synchronize the time range with the given frequency. Furthermore the different parts of the variable and the number of samples for the FFT can be selected. Unit The Unit option allows the unit of the x-axis to be set to either Frequency or Harmonic Order. When Harmonic Order is selected, the nominal frequency can be set. The nominal frequency is not restricted to the network frequency. Display On the Advanced page the display of the FFT results can be toggled between the Spectral Line and a solid Curve.

17.5.3

Calculated Results

Some plot types, such as the VisPlot, have the option to define a ’User Defined Signal’. The ’User Defined Signal’ option allows calculation of additional results based on the arithmetic manipulation of one or more results calculated by PowerFactory and recorded in a result object (ElmRes ). As the calculated result object is used to plot additional values based on other recorded values, the calculated result object is stored within the relevant VisPlot object under the virtual instrument panel and the graphics board in the data manager. To define a new Calculated Result, first perform a simulation, record a result in a result object and create a VisPlot. Double-click on the Visplot or right-click on the Visplot and select Edit and define at least one curve from the results stored in the result object. Once at least one curve is assigned in the VisPlot, the ’User Defined Signals’ dialogue should become visible as shown in Figure 17.5.11.

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Figure 17.5.11: The calculated result object

Click on New to create a new calculated result. An example of the calculated result object dialogue is depicted in Figure 17.5.12.

Figure 17.5.12: The calculated result object

The calculated result object dialogue includes the following fields: Name the name of the calculated result object Input Parameters • Results defines the result object from which the arithmetic operands are located. • Operands defines the elements and variable names of the operands within the result object. Additional operands can be inserted or appended by Mouse over Operand row → Right-Click → Click Insert Row(s) or Append Row(s) or Append n Row(s). DIgSILENT PowerFactory 15, User Manual

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CHAPTER 17. REPORTING AND VISUALIZING RESULTS Result • Name defines the name of the user defined curve • Description a free text field for description of the curve • Unit user defined variable unit • Formula DSL expression for arithmetic calculation, operands are defined in accordance with the naming convention in the ’Input Parameters’ field i.e. in1, in2, in3 etc. Refer to section 26.12 for more information on DSL and DSL syntax.

17.5.4

The Vector Diagram

A vector diagram is used to visualise complex values such as voltages, currents and apparent power as vectors. A complex variable can be defined and shown in one of two different representations: • Polar coordinates, e.g. magnitude and phase of the current • Cartesian coordinates, e.g. active-and reactive power There are predefined vector diagrams for calculation results. The predefined vector diagrams can easily be created using the context sensitive menu of a branch: • right-click a branch in the single line graphic or in the data manager. • select the option Show → Vector Diagram→ . . . from the menu • select one of the predefined variable, i.e. Voltage/Currents The example in Figure 17.5.13 shows the voltage and current at one terminal of a line.

Figure 17.5.13: Vector diagram of voltage and current at a point on a line 284

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Note: A vector diagram can only be shown when branch elements like lines, load, transformers, etc. are selected. The vectors of the voltage, current or power across the elements or at the nodes connected to the elements are shown in diagrams. The vector can be shown after a load-flow calculation or before and after a transient RMS simulation.

A vector diagram VecVis can be added to the current VI panel, in a similar fashion to the addition of a subplot. To do this, press the icon and select a Vector Diagram (VecVis) from the pull down list. In the edit dialogue, variables can then be shown as described in Section 17.5.2 (The Subplot). The objects and variables of the vector diagram can be changed manually by editing the dialogue. To open the dialogue, double-click on the vector diagram. Alternatively right-click on the diagram and select: • Default Vectors → . . . to select a predefined vector from the list. • Label of Vectors to change the label of the displayed elements shown in the diagram. • Jump to Element to select one of the elements that is connected to the currently displayed element. • Set Origin to set the origin of the diagram to the position selected with a mouse-click. • Center Origin to set the origin of the diagram in the middle of the plot. The X And Y Axes In most plots, the x and y scale are given by the minimum and maximum value of each scale. A vector diagram can’t be defined using minimum and maximum for each scale because the x- and the y-ratio must be equal. The ratio for each unit is therefore set as the parameter units per axis tick. In addition the location of the origin can be defined. If all shown variables have the same unit, the axis are labelled with values and unit. If there is more than one unit, the labels show ticks. A legend showing the ratio of the units is added in the bottom-right corner of the plot. The balloon help of the scale highlights the absolute values for each unit. Editing the Unit/Tick To modify the scale of an axis the Scales table in the edit dialogue can be changed. The column "Unit" defines the unit and the column "Scale" defines the ratio in units per tick with a higher ratio compressing the vector. If the "Auto Scale" option in the dialogue is turned on, the scales are adapted whenever a new calculation is ready. Turn off "Auto Scale" to keep the defined scale limits. Setting the Origin The origin position of the vector plot can be changed either graphically or with the dialogue: • Right-click the vector plot and select Set Origin. This will move the origin to the right-clicked position. • Modify the "x-Min." and "y-Min." values in the plot dialogue to the starting value of the x-and y scale. Changing Coordinates The plot displays the vectors in cartesian or in polar representation. The grid of a polar plot is shown as circles and can be altered as described in Section 17.5.2 (The Subplot). The representation setting is also used for the mouse position display in the status bar. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 17. REPORTING AND VISUALIZING RESULTS The option Polar in the context sensitive menu toggles between representation in polar and cartesian coordinates. This representation can also ba changed on the Advanced page in the edit dialogue. Label of Vectors In the edit dialogue as well as from the context sensitive menu of the plot, the label of the vector can be displayed in the different coordinate representations. The different coordinate systems allow display with either the real and imaginary values or the magnitude and phase angles of the vectors. Changing the Object There are two different ways to change the objects for which the vector plot is made, either: • Right-click on one of the vector plots and select Jump To. This shows a list of all connected elements from which one can be selected. Here the side of a branch element is automatically checked. The Jump To option is not available if there is more than one element shown in the same plot or if there are no calculation results available. • Double-click the "Element" column in the variables table in the plot dialogue, as depicted in Figure 17.5.14 and select a new Object from the drop-down list.

Figure 17.5.14: Variable list of a vector diagram

Changing the Variables There are two different ways to change the displayed variables: • Right-click the vector plot and select the Default Variables option. This will show a list of predefined variables. This option is not available if there is more than one element shown in the same plot or if there are no calculation results available. • Double-click the "Var. x-Axis" column in the variables table in the plot dialogue, as depicted in Figure 17.5.14 and select a new variable from the drop-down list. The variables shown in the list are either the magnitude or the real-part of the vector. The angle or the imaginary part are set automatically. The selection list is empty when no calculation results are available.

17.5.5

The Voltage Profile Plot

Background The Voltage Profile Plot VisPath shows the voltage profile of a radial network based on the networks load-flow results. The Voltage Profile Plot is directly connected to a feeder object defined in the network, so it can only be created for parts of the system where a feeder is assigned. The Voltage Profile Plot requires a successful load-flow calculation before it can display any results and hence it can not be created if there is no load-flow calculated. The easiest way to create a voltage profile plot is to define the plot directly from the single line graphic. 286

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17.5. VIRTUAL INSTRUMENTS How to create a Voltage Profile Plot There are two methods to create a Voltage Profile plot. Either from the single line graphic or from the data manager (or calculation relevant objects filter). To create a voltage profile plot directly from the single line graphic follow these steps: 1. First define a feeder for the part of the radial network where a voltage profile plot is required. To define a feeder, right-click on the cubicle at the beginning of the feeder and then select Define → Feeder. . . 2. Right-click a branch (ElmLne) of a pre-defined feeder. Next select Show → Voltage Profile from the context sensitive menu. PowerFactory will then create a new object VisPath diagram showing the voltage profile for the feeder. To create a voltage profile plot directly from the Data Manager (or calculation relevant objects filter) follow these steps: 1. Navigate to the Feeder grouping objects within the data manager (Project → Network Model→ Network Data→ Feeders). 2. Right-click on the icon of the feeder object for which the voltage profile is required. 3. Select Show → Voltage Profile from the context sensitive menu. Note: The option Show → Voltage Profile is only available after a load-flow calculation and only if the results of the calculation are valid.

Interpreting a Voltage Profile Plot The voltage profile plot shows the voltage of terminals or busbars along the length of a feeder. The variable(s) shown by the plot can be changed. If there is no valid load-flow calculation the plot remains empty. An example of a voltage profile plot is shown in Figure 17.5.15.

Figure 17.5.15: Example of a voltage profile plot DIgSILENT PowerFactory 15, User Manual

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CHAPTER 17. REPORTING AND VISUALIZING RESULTS Click on the curve to mark the busbar positions (points) on the voltage profile. Like most plots available in DIgSILENT PowerFactory , the voltage profile plot can be labelled. See the context sensitive menu or the description of the result graphs for details. The plot in the example shows the default settings, which is voltage m:u with the unit "p.u." shown as the y-axis variable. The position of the busbars (x-axis) is shown as the distance from the beginning of the feeder. The unit is "km". The variables shown for the busbars can be changed by the user through the edit dialogue of the plot. Customising the Voltage Profile Plot Changing the x-axis variable To change the x-axis variable of the voltage profile follow these steps: 1. Double left-click on a blank area of the plot to open the voltage profile plot dialogue box. 2. On the Scale page of the Edit dialogue a list box defines the x-axis variable. By default ’Distance’ is selected. This shows the distance from the beginning of the feeder in ’km’. There are two other options: Bus Index When Bus Index is selected, each bus is numbered sequentially from the beginning of the feeder and all of the buses are displayed equidistantly on the plot. Other The Other option allows plotting against a user defined variable. Only variables available at all terminals in the feeder can be used. The software variable name must be typed in the ’Variable’ textbox. For example, to display on the x-axis the load at each terminal, the variable ’m:Pload’ could be used. Note, do not enter the single quotes around the variable name. Changing the y-axis variable The y-axis variable(s) can also be user-defined. The predefined variable for the plot is the voltage m:u with the unit "p.u.". Any other variable available at all busbars in the feeder can be used as an alternative. To change the variable shown, follow these steps: 1. Double left-click on a blank area of the plot to open the voltage profile plot dialogue box. 2. Select the Curves page. At the bottom of the page there is a table called Variables. To manually add a user-defined variable double-click in the Variable cells. For example, to display the positive sequence voltage, replace the variable m:u with the variable m:u1. Right click the table and select the option Append Rows to add additional curves to the plot. Changing the branch colouring settings By default, any branch with a loading greater than 80 % will appear in red colour on the voltage profile plot. To adjust the colour and the loading limits follow these steps: 1. Double left-click on a blank area of the plot to open the voltage profile plot dialogue box. 2. The Branch Colouring settings define the settings for the branch coloring at the bottom of the Scale page. Any branches that are loaded less than the Lower Limit will be coloured according to the colour next to the Lower Limit variable. Likewise, any branches loaded greater than the Upper Limit will be coloured according to the colour next to this variable. This concept is illustrated in Figure 17.5.16. 288

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Figure 17.5.16: Changing the branch colour settings

The Parallel Branches option is required because the voltage profile plot only shows a single connection line between nodes, regardless of how many parallel branches connect the two nodes. If there is a situation where one of these parallel lines is below the Lower Limit and another is above the Upper Limit, then the parallel branches option determines whether the ’single’ line in the voltage profile plot is either the line with the maximum loading or the line with the minimum loading. Typically, most users are concerned with the maximum loading, so the default of Show Maximum will be fine in the majority of cases. Changing the busbar names colour The colour of the busbar (terminal) names on the voltage profile plot can be altered according to the user preference. To change the colour setting follow these steps: 1. Double left-click on a blank area of the plot to open the voltage profile plot dialogue box. 2. On the Advanced page towards to centre, the Colouring of the busnames shown in the plot can be changed by altering the setting Show Busnames. The meaning of each option on the advanced page are as follows: Off does not display any bus names. Black shows all names in black font style. Coloured acc. to Feeder colours the bus names according to the colour of the different feeders. Some other ’nice to know’ features of the Voltage Profile Plot To access the context sensitive menu, right-click on the plot or on the profile. The context sensitive menu shows additional functions regarding the voltage profile plot including: Edit Feeder Open the edit dialogue of the feeder related to the plot. Edit Data Right-click on a branch in the plot to open the edit dialogue of the selected line, transformer or other element. Edit and Browse Show the selected element in the data manager. Mark in Graphic Mark the selected element in the single line graphic(s).

17.5.6

Schematic Visualization

In addition to the voltage profile, the Schematic Path VisPath object can be used to show the schematic diagram of a radial network. The usage and the different options available for this plot are similar to the voltage profile plot detailed in Section 17.5.5. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 17. REPORTING AND VISUALIZING RESULTS As the name implies, the Schematic Path diagram shows a schematic of a radial network. Similar to the voltage profile plot, a Schematic Path diagram is also directly connected to a defined feeder in the network, so it can only be created for the parts of the system with which a feeder is defined. Also the Schematic Path can only be shown or created, if a load-flow is calculated for the system. To create a schematic diagram: • To define a feeder in the radial network, right-click on a switch in the single line graphic or in the data manager and then select Define → Feeder. . . . • The context sensitive menu of a branch with a defined feeder will now show the option Show → Schematic Visualization→ Plot. PowerFactory will create a new VisPath and the schematic diagram showing the profile for the radial network. • In the calculation relevant objects or in the data manager select the feeder object and select Show → Schematic Visualization→ Plot from the context sensitive menu. In the plot, the terminals and busbars are displayed as well as the electrical elements belonging to the feeder depending on the real distance of the network or on the bus index, where the distance between every node is constant. Schematic Single Line Diagram Another function to show the schematics of radial networks is the Schematic Single Line Diagram. These functions are convenient when no single line graphics of a network exists and one wants to let PowerFactory draw the schematic of a radial network automatically. These functions can be activated from the context sensitive menu of the branch element with a defined feeder similar to the voltage plot or the schematic plot described above. Using the option Show → Schematic Visualization→ . . . two slightly different operations can be used: Distance PowerFactory will draw automatically from the database a single line diagram for the radial network defined by the feeder. The distances between the terminals/busbars in "km" are set automatically according to the distances specified in the lines. Bus Index Similar to the schematic diagram the distances between the terminals/busbars will be neglected and a standard value will be used for all terminals. Note: Remember to run a load-flow prior to activating these functions. Otherwise you will not have access to the options.

17.5.7

The Waveform Plot

The waveform plot VisHrm is used to display the voltage or current waveform after a harmonics loadflow calculation. Harmonics are typically emitted by a harmonic voltage or current source described in Chapter 23: Harmonics Analysis, Section 23.5.5. The waveform is calculated according to the following formula:

𝑢(𝑡) =

𝑛 ∑︁

𝑢(𝑖) · cos(2𝜋(𝑓 (𝑖) · 𝑡 + 𝜙(𝑖))

(17.1)

𝑖=1

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17.5. VIRTUAL INSTRUMENTS where: 𝑖 𝑛 𝑡 𝑓 (𝑖) 𝑢(𝑖) 𝑝ℎ𝑖(𝑖)

Index of frequency Number of frequencies Time Frequency at index i Magnitude at frequency i Angle at frequency i

If a successful harmonic load-flow calculation with the option All Frequencies is performed, the waveform plot will show the results of any distorted or pure sinusoidal variable, e.g. voltages or currents, from any element in the network. The waveform plot can be created even if there is no load-flow calculated. icon and select a Waveform Plot(VisHrm) To create a waveform plot on the current VI panel, press the from the pull down list. More than one subplot may be created at once by setting the Number of VI(s). The new empty subplots appear with standard settings. The usage, settings and tools for this plot type are similar to the subplot. A detailed description can be found in 17.5.2 (The Subplot), although the definition of variables is slightly different. The variable definition requires a reference to the result object and the element as per the Subplot, but in contrast to the Subplot, the magnitude of the variable and the angle relating to the magnitude can also be defined. The appropriate angle is automatically matched to the selected magnitude, if such angle is available in the results and if the variable is a voltage or a current. When no appropriate angle is found, one may be selected manually. Although the angle can be defined, the parameter is not obligatory. Figure 17.5.17 shows an example for defining a variable in the VisHrm.

Figure 17.5.17: Defining variables in a waveform plot (VisHrm)

The Waveform Plot Settings Most other settings/options for the waveform plot are the same as the settings for the Subplot (VisPlot). See Section 17.5.2 (The Subplot) for more information. However there are some specific settings unique to the waveform plot, these include the step size and time range. The step size and time range are specified within the waveform plot settings object stored in the "Settings" directory of the active project. To change the waveform plot settings either press the Calculation button in the dialogue of the plot or select Calculation in the context sensitive menu on the plot. The Settings Waveform Plot SetWave object holds the Step Size and the Range for the calculation of waveforms in the Waveform Plots (see Figure 17.5.18).

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Figure 17.5.18: The waveform plot settings dialogue

Step Size The visible waveforms are calculated by the waveform plot itself. To avoid errors the Step Size must be smaller than half the period of the highest frequency calculated by the harmonics load-flow. To guarantee that this criteria is always fulfilled, independent of the harmonics calculation, the Step Size is entered in Number of Samples in Highest Frequency. The Highest Frequency and the resulting Step Size are shown for information. Range To be independent of the basic frequency, the time range of the waveform is entered in Number of cycles of Basic Frequency. Basic Frequency and the resulting Range are shown for information.

17.5.8

The Curve-Input Command

The curve input command is used for measuring printed curves. The original curves must be available in windows metafile (*.wmf) or in bitmap (*.bmp) format. The graphics file is displayed as a background in a curve input plot. This plot then allows for defining plot points by successive mouse clicks. The curve input plot (VisDefcrv ) allows the measurement and editing of single curves or group of curves at once. The measured curve points are stored in a Matrix object. The positions of the axis in the curve input plot can be set by the user. Special functions for groups of curves allow for x-value synchronization and many other facilities to make their input quick and easy. Creating a Curve-Input Plot The special Curve Input virtual instrument plot VisDefcrv is needed for measuring curves. Such a plot, like all other virtual instruments, is displayed on a Virtual Instrument Panel. A new virtual instrument of the graphics window. panel is created with the new command in the file menu or the new icon To create a new Curve Input plot, right-click an empty panel, or press on the panel button bar and select the Curve-Input (VisDefcrv ). Double-click the curve input plot to open the curve input option dialogue shown in Figure 17.5.19. The Input Options The input options are used to select the graphics file which is to be measured. Only windows metafile (*.wmf) or bitmap (*.bmp) formats are supported. The x-scale and y-scale settings are used to set the range and type of the axes of the curves as they are in the graphics file.

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Figure 17.5.19: Editing the curve input plot

Two different types of curves can be input: Single Each matrix input defines a single curve. The first column in the matrix holds the x-values, the second one the y values. Other columns are ignored. Set of Curves Only the first matrix is used for input. The first column in the matrix holds the x-values, the other columns hold the y-values of each curve in the group of curves. The measured curve is drawn between the measured points by interpolation. This is important for later when the measured curve is used with a specific interpolation. Setting the correct interpolation mode when measuring the curve causes a better fit while avoiding excess curve point definitions. Available modes of interpolation: • Linear • Cub. Spline • Polygon • Hermite The Context Sensitive Menu To open the context sensitive menu for Curve Input, right-click the curve input plot. The menu is used DIgSILENT PowerFactory 15, User Manual

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CHAPTER 17. REPORTING AND VISUALIZING RESULTS to select the curve for which points are to be measured or edited, to select the measurement mode, to synchronize x-values by interpolation, etc as detailed below: Grid Opens the grid layout dialogue Curves Used to switch from single to set of curves mode. Interpolation Selects the interpolation mode Interpolate All Interpolates undefined y values for all curves for all defined x-values Interpolate N Interpolates undefined y values of curve N for all defined x-values Delete Curve N Removes curve N from the matrix Add Curve Appends a new curve Set Axis With this option the origin of the axes and the length of the axes can be adjusted according to the figure imported. Origin Sets the origin of the graph to be inserted. x-Axis Sets the x-axis independent on the y-axis. x-Axis (y=Origin) Sets the x-axis dependent on the y-axis origin. y-Axis Sets the y-axis independent on the x-axis y-Axis (x=Origin) Sets the origin of the graph to be inserted. Origin Sets the origin of the graph to be inserted. Input Specifies the input mode: Off Switches off the measurement mode x/y-Pairs Each left mouse click adds a point to the curve. Drag & Drop Turns on the ’edit’ mode: all points can be dragged and dropped to change their y-position or left click and delete the point with the ’Del’ key.] Active Curve Sets the curve to modify How to Scan curve(s) using the curve-input plot: • Create a virtual instrument panel with a curve input plot • Open the curve-input dialogue with a double-click and set the following options – Select the background file – Select Single or Set of Curves in the Curves Listbox – Select the interpolation mode – Select on or more Matrix objects in the table named Curves. At least two columns must be already present in the matrix object. • Close the dialogue. • Define the axis position to adapt the curve input to the background plot: – Select the graphic cursor – Right-click the plot and select Set Axis - Origin. Left click the origin of the plot – Right-click the plot and select Select Set Axis - x-Axis. Left click the end of the x-axis of the background plot. – Right-click the plot and select Select Set Axis - y-Axis. Left click the end of the y-axis of the background plot. 294

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17.5. VIRTUAL INSTRUMENTS • Open the curve-input dialogue and adapt the scale of the curve input plot to the scale of background plot • Right-click the plot and select the Active Curve option and activate the first curve. The option is not available when – There is no Matrix object selected in the Curves table of the dialogue – One of the matrix object(s) has less than two columns • Right-click the plot and select the Input option. Select the input mode. With the first curve, select the with x/y-Pairs option. • Left click the curve to set x/y values. • Right-click the plot and select the Input - Off option to finish the definition of the curve

17.5.9

Embedded Graphic Windows

Some dialogues contain embedded graphic windows to visualize input settings. An example is shown in Figure 17.5.20 for the parameter characteristic dialogue. An embedded graph has some similar functionality and features to the subplot, detailed in section 17.5.2.

Figure 17.5.20: Example of an embedded graph

Similar to the plots on a VI page the mouse position in the embedded graphic is shown in the status bar. The context sensitive menu of the embedded graph offers commands for printing and zooming. To access the context sensitive menu, right-click on the embedded graphic. Print Picture This option opens the print dialogue. The default print format for embedded graphs is A4. The printer orientation is set to the orientation of the embedded graph. The print dialogue includes an option to preview the printed area. Zoom In This option changes the cursor to a magnifying glass. Drawing a rectangle with the cursor will enlarge that area. Zoom Back This option restores the previous zoom area. Zoom All DIgSILENT PowerFactory 15, User Manual

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CHAPTER 17. REPORTING AND VISUALIZING RESULTS This option zooms out to the complete window. Change Viewpoint . Press the left mouse button, hold it down This option changes the arrow to the move arrow and move the mouse inside or outside the window. This will move the zoomed area in that direction. Press the right mouse button to change the cursor back again. In some embedded graphs an option exists to define Limits in the dialogue. Pressing this button will open a small dialogue where the minimum and maximum of the x-axis can be changed, or the Scale button will reset the settings and scale the axis automatically.

17.5.10

Tools for Virtual Instruments

Different kinds of plots are used to display calculation results or device data. There are numerous tools which help the user interpret and analyze data and calculation results. Most of the tools are accessible directly through the "status bar" of PowerFactory or through the context sensitive menu. To activate the context sensitive menu, right-click on the curve or on the plot background (depending on the desired function). Edit Dialogues To access the Edit dialogue of the plots, double-click on the background of a plot or Right-Click → Edit. A quick way to access information pertaining to the plot is to double-click directly on the element requiring change. This includes: Legend Manipulation of the legend text and representation. X-Axis The x-axis limits, scales and variable representation and auto scaling options of the current graphics board or panel. Y-Axis The y-axis limits, scales and variable representation and auto scaling options as well as the variable displayed. A double-click on other positions will open the plot dialogue. The Status Bar In the status bar of PowerFactory on the bottom of the program window useful information regarding the data shown in the curves can be obtained. • First the value of the mouse position in the diagram is displayed in the status bar, similar to the information shown with an open single line diagram. • When a curve is clicked and marked with a cross, the cross value is displayed in the status bar and remains unchanged until the cross is set to a different position. If there is no cross on the active page the status bar value is reset and no longer displayed. Some plots have different scales on one axis, these plots can not display a value in the status bar. • The option Curve-Tracking can be found in the status bar, normally in a grey font style. Doubleclick on this font to enable the "Curve-Tracking" mode. In this mode a cross will appear if the mouse arrow is near a curve. Hold the mouse pointer still for one second and the x- and y-value will be shown in a balloon window. 296

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17.5. VIRTUAL INSTRUMENTS Labelling Plots There are different styles of labels available for labelling curves and graphics. Setting labels is possible in most of the different plots, although some of the labels are not available in all plot types. Labels are all created in the same way. To create a label, first click on the curve to mark the desired data point with a cross, then right-click on the plot to display the context sensitive menu. The option Label → Insert . . . Label can be selected for and in the toolbar, which can be used different label types. Alternatively there are also two icons to create labels directly. After selecting the appropriate label from the sub-option of label, a rubber band from the cross to the mouse is shown. A click with the left mouse button sets the label, the right mouse button cancels. The following different labels are available. The Text Label The text-label (Add Label with Text option) displays user defined text above and below a line connected to the curve. Edit the label to change the text shown. The Value Label The value-label (Add Label with Value of the Current Curve option) displays the x/y coordinates of the cross. The label is a text-label filled with the marked coordinates. Edit the label to change the text. The Format Label The format-label (Add Label with definable format option) uses a form to print the displayed text. The form can be selected as local for each label or a common label can be sued for all plots of the same type in the active project. More information regarding each labelling option is provided in the following sections. The Text and Value Label The text-label and the value-label are defined using the same object type, the VisValue. The VisValue labels curves or graphics displayed in plots. The text of the label is written above and below a horizontal line and the line is connected to the curve/graphic with a ’rubber band’. After creating labels, they can be freely dragged across the plot while staying connected to the data point on the curve. To change the text of the label, double-click the label or the ’rubber band’. The edit dialogue of these (VisValue) object is depicted in Figure 17.5.21.

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Figure 17.5.21: X/Y value dialogue

Value Value displays the connected curve position of the label. For labels created as a value-label this position is displayed automatically as label text. "x-Axis" displays the x axis value and "y-Axis" the y axis value. "Time" is visible only for plots showing a trajectory. Text on Top Text written above the horizontal line. Text on Bottom Text written below the horizontal line. Delete Label when a new Simulation is started Labels in plots showing simulation results are usually automatically deleted when the simulation is started again. To keep labels in such plots, e.g. to compare curves with the last run, turn off this option. The default of this option is on. The Format Label Like the text-label and value-label, the format-label (VisLabel) is also set in plots to label curves or graphics. However, the format-label displays text printed using a form. The form is different for each type of diagram. It is either defined locally per label or defined for all diagrams of the same type in the activated project. The format-label dialogue is shown in Figure 17.5.22.

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Figure 17.5.22: The format-label dialogue

Value Value displays the connected curve position of the label. "x-Axis" displays the x axis value and "y-Axis" the y axis value. Data Object "Data Object" is a reference to the object of which the plotted curve parameter is derived. If "Data Object" is not set the label itself is taken as the "Shown Object". Shown Object The object output by the form, see "Data Object" described above. Edit Used Format Shows the used "Format Manager". The used format is either the local format or the one defined for all plots of the same type in the active project. Create Local Format Creates a new "Format Manager" valid for the current label only. The forms can be edited without influencing other labels in the same plot or in the active project. The "Create Local Format" button is replaced by the "Set Default Format" when a local format is defined. Set Default Format Removes the local format. The format used is the one used for all plots of the same type in the active project. The "Set Default Format" button is replaced by the "Create Local Format" when the local format is reset. Delete Label when a new Simulation is started Labels in plots showing simulation results are usually automatically deleted when the simulation is started again. To keep labels in such plots, e.g. to compare curves with the last run, turn off this option. The default of this option is on. The context sensitive menu of the format labels provide access to further options. To access the context sensitive menu, right-click on the format label. The following options can be selected: Border A simple border of the selected label can be turned on or off. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 17. REPORTING AND VISUALIZING RESULTS Form The format options can be directly accessed by Edit used Format and Create Local Format for the marked format label. Reconnect with... Reconnects the format label to another curve or data point. The Constant Value The constant label (VisXvalue) is used to display a straight line. The VisXvalue can be used to display y-values for a constant x-quantity or x-values for a constant y-quantity. In some plots like the overcurrent plot, constant labels are created and deleted automatically for certain simulations e.g. to visualize the short-circuit current for relays. The look of constant labels can be varied with different settings including the label location, intersection values and other options. The dialogue of the constant label is depicted in Figure 17.5.23.

Figure 17.5.23: The constant label dialogue

To insert a constant label into a diagram or plot, right-click on the plot and select the option Set constant → x-Value or Set constant → y-Value to place a constant x-value or a constant y-value respectively. The dialogue for the VisXvalue object will be displayed as shown in Figure 17.5.23 and a horizontal or vertical line will be displayed at the value specified in the dialogue. There are different options and styles for the constant label: Name defines the name of the constant line displayed in the plot. Style changes the representation of the constant label as follows: Line Only displays only the solid line and the related label. Line with Intersections shows a solid line including label and indicates the values when intersections with the curves of the plot. Short Line Only (Left/Right indicates the constant value at the bottom/top respectively at the right/left side of the plot. Short Line/Intersection (Left/Right) indicates the constant value at the bottom/top respectively at the right/left side of the plot and the intersections with curves. Intersection Only shows only the intersection points with the curves. 300

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17.5. VIRTUAL INSTRUMENTS Label defines the position of the constant value label as follows: None displays no label at all. Outside of Diagram creates the label between the border of the VI and the diagram area. Labels of constant x values are created above the diagram area, labels of constant y values are created right of the diagram area. Above Line (right) shows a label above the line if y is constant, the label will be on the right hand side. Below Line (left) shows the label below the line on the left hand side. Left of Line (top) shows a label on the left side of the line if x is constant, the label will be on the top end. Right of Line (bottom) shows the label right of the line on the bottom end. Value defines the constant value, either X or Y. The dialogue shows if either an X or Y is set. Also the actual position of the cross will be shown as an x- or y-value. It is not possible to change a constant X into a constant Y label other than by removing the old label and creating the new one. Colour specifies the colour of the line and the labels/intersections. Linestyle and Width specifies the line style and line width for the line shown. Invisible if "Show Values" is set to "Intersections Only". For constant x-values in time-overcurrent diagrams there exists additional options: x-Value is Displays the type of current displayed. Visible only for constant x values in time overcurrent diagrams. Show Values The constant value can be displayed as a line, as intersections with the curves/graphics or both. "Line Only" shows a vertical or horizontal line without labels for the intersections with the curves. "Line with Intersection" creates crosses at the intersection of the line with the curves. For constant x values the y value is displayed at the crossing ant the other way round. The values and their unit are coloured like the curve crossed. Intersections Constant x values created automatically in the overcurrent plot are displaying the shortcircuit current. To get the tripping times "Intersections" can be set to SHC Currents. "All" would display the intersection of the relay curve ignoring the type of current. Visible only for automatic constant x values showing currents in the time overcurrent diagrams. Set User Defined The button "Set user defined" is visible for constant values created by the shortcircuit in overcurrent plots. Labels showing this button display the short-circuit current. The labels are deleted whenever a new short-circuit was calculated. If one wants to modify and keep the label even if a new short-circuit was calculated the label must be changed to user defined. The Straight Line There are various ways of inserting lines into a plot. Another way is to insert a Straight line. To create a straight line right-click on the plot background or on a marked point and select Straight line. The Straight Line → . . . includes the following options: Set Secant to add a line directly through the selected data point. Through Point defines a graphic line through the selected data point with a defined gradient and gives back the function of the line. User Defined defines a line independent from the curves shown with a defined gradient and y-offset. The function of the inserted line can also be seen, when holding the mouse arrow over the line for 1 second. The options of the line dialogue is similar to the options for the constant value (VisXvalue). DIgSILENT PowerFactory 15, User Manual

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CHAPTER 17. REPORTING AND VISUALIZING RESULTS Curve Filter Curves shown in the plots and diagram can be filtered using the Curve Filter. The option Filter... from the context sensitive menu displays the filters available to be applied to the data read from the result object. Another way to access this function is from the "edit" dialogue of the plot. Here the Filter... button can be pressed. The Figure 17.5.24 shows the dialogue of the function.

Figure 17.5.24: Defining a curve filter

The Curve Filter specifies the type of filter applied to the data read from the result object. This object is a filter applied to curves in plots. There are different filter types available. The following filter settings are available. (N=number of points in the original curve, K=number of points in the filtered curve) Disabled No filtering will be performed. K=N. Average The filtered curve is the running average of the last n points. The first n-1 points are omitted. K=N-n+1. Balanced Average The filtered curve is the running average of the last (n-1)/2 points, the current point and the next (n-1)/2 points. This filter thus looks ahead of time. The first and last (n-1)/2 values are omitted, n must be an odd number. K=N-n+1. Purge Points by averaging The filtered curve contains the averages of each block of n values. K=N/n. This filter may be used to speed up the display of large curves. Purge Points The filtered curve only contains every n-th value. All other values are omitted. K=N/n. This filter may be used to speed up the display of large curves. Note: A curve filter can only be applied at the end of the simulation or measurement, points added during a simulation or measurement are not filtered. The option Filter... is not available in all plots.

Border • Off • Simple • 3D • 3D with label The border with 3-dimensional effect and label will insert an additional label on the bottom of the selected plot. This label can now be defined by double-clicking on it. Furthermore the text style can be altered by choosing the option Select Font for Border. Export of Curve Graphic

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17.5. VIRTUAL INSTRUMENTS The whole diagram or plot can also be exported for further usage in reports. Thereto first mark the plot which is to be exported to a graphic file. Then select the option File → Export. . . → . . . from the main menu. There is the selection between the export into a Windows MetaFile (*.wmf) or into a Bitmap File (*.bmp). Export of Curve Data The export of curve data is available for a single VI or for the variables of the entire VI panel. Hence there are different ways to access the "ASCII Results Export" command ComRes of curve data, described in the following paragraph. The export directly from the result file gives the opportunity to directly export several variables at once and is described in more detail in Section 17.2.4(Exporting Results). Exporting curves of a single VI: • Press the Export... button in the right side of the dialogue box of a virtual instrument. • Right-click on the VI and select Export... from the context sensitive menu. Exporting curves of the entire VI panel: • Press the Export Results... button on the Results page of the VI panel. • Right-click on an empty area of the VI panel and select Export Results... from the context sensitive menu. Note: If in one plot or on one VI panel variables are shown from several result objects, a dialogue will appear before the export command, where you have to select one result file from the list.

This function will export the data from the displayed curve with the given time range as ASCII text to the following programs/files: • Output Window • Windows Clipboard • Measurement File (ElmFile) • ComTrade • Textfile In this dialogue the individual step size can be set, the columns of the result file and the header for the export as can be seen from Figure 17.5.25.

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Figure 17.5.25: Command dialogue of the ASCII result export

Various VI Tools Grid This option in the context sensitive menu displays a dialogue to turn on/off the available grid lines. For both x- and y-axis a main grid and a help grid can be displayed in the plots. Furthermore depending on the type of plot - the representation of the different ticks on the axes can also be specified. Autoscale X, Autoscale Y Changes the autoscale settings of the plot. Off turns off the auto-scale mode. On performs an auto-scale at the end of the simulation or calculation. Online is available in simulation plots only and tests the plot limits after each new simulation point.These settings can also be defined in the "edit" dialogue of the x- and y-axes. x-Scale(s), y-Scale(s) There are two options in the x-scale or y-scale entry. Edit displays a dialogue to modify the scale settings like minimum, maximum and other settings. Scale Automatic calculates the minimum and maximum of the curve and adapts the scale limits.These settings can also be defined in the "edit" dialogue of the x- and y-axes or by double-clicking on the corresponding axis. Show dx/dy Right-click on data point on a curve and select Show dx/dy from the menu. The two lines will appear, which are connected to the tip of the mouse pointer. A balloon window will show the x304

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17.5. VIRTUAL INSTRUMENTS and y-difference between the selected data point and the point where the tip of the mouse pointer is in the diagram. Additionally the gradient is displayed.

17.5.11

User-Defined Styles

Each VI panel, each virtual instrument and every single plot uses a style where line-widths, fonts, brushes and other graphical settings are defined. These objects normally use predefined styles. In PowerFactory there are six predefined styles available: • Default - Standard English Text and Symbols • Gr Default - Greek Symbols • Tr Default - Turkish Symbols • Paper • Gr Paper • Tr Paper These styles can be modified for all VIs or only for single plots. For this user-defined styles can easily be created and specified. The base for an user defined style is always the previous default style. There are several ways to select a predefined or user-defined style or change between the available styles. • The easiest way is using the list-box in the toolbar by clicking and selecting one of the available styles. • A style can be selected from the Style → Select Style→ . . . in the context sensitive menu of the VI. • A style is selected in the VI-Style list-box on the Advanced page of the VI Panel dialogue. The user-defined styles are stored in the settings folder element of the active project. Therefore each project has its own ∖ Settings ∖ Styles ∖... path and user defined styles. Only the changed elements are stored in the project, the unchanged ones are the ones predefined in the default style. The settings folder elements can be seen in the database in Figure 17.5.26.

Figure 17.5.26: The settings folder in the database

Defining Styles for the VI Panel The Style → Create new Style option in the context sensitive menu of the VI panel SetVipage or every plot on the panel is selected to create a new style for the actual virtual instrument panel. Insert a name for the style to be created in the input dialogue. Then the new style is added to the predefined styles and is automatically selected for the current VI panel. The created style is not set automatically in other VI panels of the project. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 17. REPORTING AND VISUALIZING RESULTS If a user-defined style is selected for the current VI panel, the Style → Edit Style option of the context sensitive menu of the panel may be selected to open the dialogue of the new panel style. Figure 17.5.27 shows the dialogue for editing the layout of the panel.

Figure 17.5.27: Editing the panel style

With the settings shown in Figure 17.5.27, mainly the layout of the title block of the VI panel is edited. Here the user can define • the different font styles for the various entries of the block by clicking on the buttons • the height and the width of the columns of the title block (see Section 9.7.3: Graphic Options) • the line width of the title block and of the page frame Defining Styles for the Virtual Instruments There is the possibility to define the x- and y-axis of the plots inside on one page. These settings then are valid every plot on panels using this style. To change the styles, right-click on a virtual instrument on the panel and select the option Style → Edit Style in the context menu. Then a dialogue will pop up containing the settings for • all x-axis of VIs using this style • all y-axis • the selected object VIsplot Double-click on the object which is to be changed. As shown in figures 17.5.28, the dialogue of the selected axis will be opened and can then be modified. 306

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Figure 17.5.28: Editing the styles of X-axis

In the dialogue the following settings of the axes can be specified for the selected style: Axis Here the style and width of the axis itself can be changed. Also the number of small ticks shown between the divisions can be chosen. Text The number of characters and the digits behind the decimal point as well as the font type and size can be specified. Distance between Axis and Text Arrow The representation can be altered between the normal style and a style with an arrow at the end of the axis with a certain width and length of its tip. Defining Styles for Single Plots In addition to the axes the presentation of the plot itself can be chosen by the user. These settings can be accessed through the dialogue shown in 17.5.29 and then double-clicking on the settings of the VisPlot object. Another and simpler way to change the settings of the style is to directly select the option Style → Edit Style of clicked Element from the context sensitive menu. These are the same dialogues shown in Figure 17.5.29 and can directly be accessed by right-clicking on the • x-axis in the plot to access the settings of the x-axis • y-axis in the plot to access the settings of the y-axis DIgSILENT PowerFactory 15, User Manual

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CHAPTER 17. REPORTING AND VISUALIZING RESULTS • on the plot itself to access the settings plot style, i.e. the grid, legend, etc.

Figure 17.5.29: Editing the settings of the plot

Figure 17.5.29 shows all different settings available for the plots on a VI panel. Thus one can Grid Options to alter the width, line style and color of the main grid and the help grid. Legend Edit the distances from the legend to axis and between the different legends. Margins Set spaces between the diagram and the surroundings. Saving Predefined Styles for Plots If the settings of the x- and y-axis, of the plot itself as well as the size of a particular plot shall be saved and then reused for further plots, there is the option Style → Save as predefined VI form the context menu of every plot or VI. This option saves the setting of the plot and stores a new VI in the list of all VIs. Hence if adding a plot the newly created VI can now be selected from the list by pressing the icon and selecting the e.g. NewName(VisPlot) from the pull down list or by using the option Create VI → . . . from the context menu of theSetVipage to add new virtual instruments to the VI panel. The new empty subplots appear with new defined settings.

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Chapter 18

Data Management 18.1

Introduction

The basic elements of project management within the PowerFactory environment were introduced in Chapter 4 (PowerFactory Overview). They allow the user to generate network designs and administer all input information and settings related to PowerFactory calculations and analyses. The project object is much more than a simple folder which stores all objects which comprise a power system model; it allows the user to do advanced management tasks such as: versioning, deriving, comparing, merging and sharing. These advanced features simplify data management in multi-user environments. The following chapters explain in more detail, each of the data management functions, including: • Project Versions; • Derived Projects; • Comparing and Merging Projects; • How to update a Project; and • Sharing Projects

18.2

Project Versions

The section explains the PowerFactory concept of a version. The section first explains what a version is and when it can be used. Next the procedure for creating a version is explained. Specific procedures related to versions such as rolling back to a version, checking if a version is the basis for a derived project and deleting a version are then explained.

18.2.1

What is a Version?

A version is a snapshot of a project taken at a certain point in time. Using versions, the historic development of a project can be controlled. Also, the previous state of a project can be recovered by rolling back a version. From the PowerFactory database point of view, a version is a read-only copy of the original project (at the moment of version creation), which is stored inside a version object (IntVersion, ). Version objects are stored inside the original project in a special folder called Versions. The concept of versions is illustrated in Figure 18.2.1. At time 𝑡0, the project SIN is created. After a time, 𝑡1, when the owner has made several changes they decide to make a copy of the project in its DIgSILENT PowerFactory 15, User Manual

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CHAPTER 18. DATA MANAGEMENT current state by creating the version ’V1’. After more time, 𝑡2, and after more changes with respect to ’V1’, another version ’V2’ is created by the owner. The version control can continue with time like this, with versions accumulating with a periodicity of 𝑡. After versions are created, the owner can revert the project to the state of the version by using the ’rollback function’. This destroys all modifications implemented after such a version was created (including all versions created after the rolled back version.

Figure 18.2.1: Project Versions

18.2.2

How to Create a Version

This sub-section describes the procedure for creating a version. To create a version of the active project follow these steps: 1. Right-click on the active project. 2. Select New → Version from the context sensitive menu. Alternatively, use the option File → New VersionEˇ from the main PowerFactory menu. The dialogue for the new version appears as shown in Figure 18.2.1. 3. Set the desired options (explained in the following section) and press OK. PowerFactory automatically creates and stores the version in the versions folder (which is automatically created if it doesn’t yet exist).

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Figure 18.2.2: The Create Project Version Dialogue

Options in the Create Project Version Dialogue Point in Time By default this is set to the system clock time when you initiate the creation of the version. However, it is also possible to enter an earlier time back to the beginning of retention period of the project. Note: Setting a Point in Time earlier than the clock time means that the version is created considering the state of the project at the time entered. This can be used for example, to revert the project to a previous state, even though you have not yet created other versions.

Notify users of derived projects If this option is enabled, when a user of a project that is derived from the active project activates their derived project, they are informed that this new version is available. Thereafter, updates of the derived project can be made (for further information about derived projects please refer to Section 18.3). Complete project approval for versioning required If this option is enabled, PowerFactory checks if all the objects in the active project are approved. If Not Approved objects are found, an error message is printed and the version is not created. Note: The Approval Status is found on the description page in the dialogue of most grid and library objects.

18.2.3

How to Rollback a Project

This sub-section describes the use of the Rollback function to revert a project to the state of a version of that project. For example, consider a project called ’V0’, created at a ’point in time’, ’t’. If a Rollback DIgSILENT PowerFactory 15, User Manual

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CHAPTER 18. DATA MANAGEMENT to ’V0’ is completed, the project returns to the state it had at the creation of ’V0’. After the Rollback, all changes implemented after ’V0’ (after V0Šs point in time) are deleted. Also, all versions newer than ’V0’ are removed. This concept is illustrated in Figure 18.2.3.

Figure 18.2.3: Example of a Rollback

To complete a ’Rollback’ 1. Deactivate the target project. 2. Right-click on the version that you wish to rollback to and select the option Rollback to this version from the context sensitive menu. 3. Press OK on the confirmation message. Note that a Rollback is not allowed (not enabled in the context sensitive menu) if a newer version of the project exists and this version is the base of a derived project. A Rollback cannot be undone! Note: A version can only be deleted if it does not have derived projects.

18.2.4

How to Check if a Version is the base for a derived Project

This sub-section explains the procedure for checking if a version is the base for a derived project. Follow these steps: 1. Activate the project. 2. Go to the versions folder inside the project. 3. Right-click on the version that you want to check. Note, do this from the right window pane in the data manager, not the main data manager tree. 4. Select the option Output... → Derived Projects. 5. A list of derived projects will be shown in PowerFactory ’s output window.

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18.3. DERIVED PROJECTS

18.2.5

How to Delete a Version

To delete a version: 1. Activate the project containing the version. 2. Go to the versions folder inside the project. 3. Right-click on the version that you want to delete. 4. Select the option Delete.

18.3

Derived Projects

This section explains the concept of a derived project. First, background on the use of derived projects is presented in sub-section 18.3.1. Then, sub-section 18.3.2 explains the procedure for creating a derived project.

18.3.1

Derived Projects Background

Often, several users might wish to work on the same project. To avoid the large amount of data duplication needed to create a project copy for each user, DIgSILENT has developed a virtual copy approach called derived projects. From a userŠs point of view a derived project behaves like a normal copy of a project version. However, only the differences between the original project version (Base Project) and the virtual copy (derived project) are stored in the database. Because the derived project is based on a version, changes made to the base project do not affect it. Like ’normal’ projects, derived projects can be controlled in time by versions, but these derived versions cannot be used to create further derived projects. Note: A derived project is a local ’virtual copy’ of a version of a base project (master project): - It behaves like a “real copy" from the user’s point of view. - Internally only the data differences between the Base Project and the derived project are stored in the database. - This approach reduces the data overhead.

In a multi-user database, the data administrator might publish a base project in a public area of the database. Every user can subsequently create their own derived project and use as if it is the original base project. Changes made by individual users are stored in their respective derived projects, so that the base project remains the same for all users. The purpose of a derived project is that all users work with an identical power system model. The derived project always remains connected to the base project. The concept of derived projects is illustrated in Figure 18.3.1; here version ’Version3’ of the base project (’MasterProject’) was used to create ’DerivedProject’. After ’DerivedProject’ was created, two Versions of it were created.

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Figure 18.3.1: Principle of Derived Projects

At any stage, the data administrator might create a version of a base project that has derived projects from other versions of the base project. The user might wish to update their derived project with one of these new versions. Alternatively, the data administrator might like to incorporate changes made in a derived project to the base project. All of these features are possible, by using the Compare and Merge Tool, explained in section 18.4.

Figure 18.3.2: Derived Projects in a multi-user database

In the Data Manager a derived project looks like a normal project. The Derived Project page of its dialogue has a reference where the user can see the base project and the version used for deriving the project. Users are notified of changes in the base project, if there is a new version of the base project (newer than the ’used’ version) which has the option Notify users of derived projects enabled (the user/administrator enables this option when creating a new version), and the option Disable notification at activation disabled (found within the derived project tab of the project dialogue). The option of updating a derived project is presented to the user when they next activate the derived project, when the conditions above are met. The newest version that can be used to update a derived project is referred to (if available) in the Most recent Version field of the dialogue. The users can compare this new version with their own derived project and decide which changes to include in the derived project. For comparing and accepting or refusing individual changes, the Compare and Merge Tool is used. For information about the Compare and Merge Tool refer to section 18.4. 314

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Figure 18.3.3: New Version of the base project in a multi-user database

Figure 18.3.4: Merging the new Version of the base project into the Derived Projects

18.3.2

How to Create a Derived Project

A new derived project is created using the Data Manager as follows: 1. Right-click the desired folder in the right pane of the Data Manager where the derived project is to be created. 2. Select New → Derived Project from the context-sensitive menu. 3. Select the source version of the base project using the data browser that appears. This will likely be the last available version of a project in a public area, created by the data administrator. 4. Press OK. Note: The base or master project has to have at least one version before other projects can be derived from it. -You cannot derive a project from a derived project. - You can check if a project is derived or not by opening the Edit dialogue of the project itself and selecting the derived project tab. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 18. DATA MANAGEMENT To create a derived project from a Base Project stored in another user’s account, you need at least read access, see Section 18.6.

After the derived project is created, it can be used like a normal project. The Derived Project can be exported as a “Regular Project" or with the Base Project. The option can be selected from the Export Dialogue.

18.4

Comparing and Merging Projects

This section describes the procedure for comparing and merging projects within the PowerFactory database. There are many circumstances when you might need to merge together data from multiple projects. For example, one of the most common would be when the data administrator updates a master project that is the base project for a derived project that you are working with. The Compare and Merge Tool (CMT) can be used to update your project with the data changes, but it also gives you control over what changes you implement. This section is separated into six sub-sections. Firstly, the background of the CMT is presented. The next sub-section explains the procedure needed for merging together or comparing two projects. Subsection 18.4.3 explains the procedure for merging or comparing three projects. In sub-section 18.4.4, the advanced options of the CMT are explained. The CMT uses a diff browser for showing the differences and conflicts between compared projects and also for allowing you to make data assignments. This is explained in sub-section 18.4.5.

18.4.1

Compare and Merge Tool Background

During collaborative working in a multi-user environment, a data administrator might often need to update the Master project to create a version based on updates completed by one or more users to derived projects of the ’Master’ project. PowerFactory has a specific tool called the Compare and Merge Tool (CMT), that is used for this purpose. This tool can also be used for project comparison in addition to the merging of project data. It is capable of a two way comparison between two projects and also a three way comparison for three projects. Internally, PowerFactory refers to each of the compared projects according to the following nomenclature: • Project - the base project for comparison. • - the first project to compare to the project. • - the second project to compare to the project and to the project (three way comparison only). The CMT internally compares the chosen projects and generates an interactive window known as the CMT diff browser to show the differences. For a two-way merge, the changes found in the Project can be implemented in the , provided that the user selects as the source ( is by default the target). When merging together three projects, the target is either the or project.

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18.4.2

How to Merge or Compare two projects using the Compare and Merge Tool

This section describes the procedure for merging together or comparing two projects using the Compare and Merge Tool (CMT). Note the comparison procedure is completed using a similar procedure but with slight differences that will also be explained here. To merge or compare two Projects: 1. In the data manager, right-click an inactive project and choose Select as Base to Compare. 2. Right-click a second (also inactive) project and select Compare to [Name of Base Project]. The CMT options dialogue will appear as shown in Figure 18.4.1. The and the project are listed in the Compare section of the dialogue.

Figure 18.4.1: Compare and Merge Tool options dialogue 3. Optional: If you want to include a third project in the comparison, the box next to must be checked. The third project can then be selected with a data browser by using the icon. Please see Section 18.4.3 for a more detailed explanation of the 3-way comparison. 4. Optional: If you decide that you need to switch the base and compare projects you can press the button. For instance in Figure 18.4.1, if you would like Project A to be the project and Project B to be the . 5. Select one of the options ’Compare only’, ’Manually or ’Automatically’. The differences between these three choices are explained below: • Compare only : If you only want to compare the two projects and no merge is desired, then select the radio button ’Compare only’. This disables the merge functionality and only the differences between the two projects will be shown. • Manually : When this option is selected, you will later be asked to make assignments (to choose the source project data for common objects that are merged together). For this option, the target project can also be selected. Selecting will merge changes into the project, whereas selecting will instead merge changes into the comparison project. • Automatically : When this option is selected, PowerFactory will attempt to automatically merge the two projects together, by automatically making data assignments. In a two-way comparison, merging will be automatically into the base project (the base is automatically assumed to be the ’target’ for the merging procedure). Note that if conflicts are detected during an automatic merge, the CMT will automatically switch to manual mode. 6. Press Execute to run the compare or merge. The CMT diff browser will appear (unless an automatic merge was selected and no conflicts were identified by PowerFactory ). Interpreting and using the diff browser is described in Section 18.4.5. DIgSILENT PowerFactory 15, User Manual

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Note: It is possible to assign user defined names for each of the compared projects to make it more convenient for remembering which project is being referred to by the CMT later on in the diff browser (see Section 18.4.5). For example, you might wish to name two compared projects something like ´ ´ SMaster’ and SUser’. Custom names can be implemented by typing the desired name in the as ... field in the CMT options dialogue shown in Figure 18.4.1. These user-defined names are limited to a maximum of ten characters.

18.4.3

How to Merge or Compare three projects using the Compare and Merge Tool

This section describes the procedure for merging together or comparing three projects using the Compare and Merge Tool (CMT). The comparison procedure is completed using a similar method to a two-way merge or compare but with slight differences that will be explained here. To merge or compare three Projects: 1. In the data manager, right-click an inactive project and choose Select as Base to Compare. 2. In the window on the right of the data manager, hold the CTRL key to multi-select a second and third inactive project. 3. Right-click the multi-selection and select the option Compare to ””. The CMT options dialogue will appear as shown in Figure 18.4.2. The , the and the project are listed in the Compare section of the dialogue.

Figure 18.4.2: Compare and Merge Tool options dialogue for a three way merge 4. Select one of the options ’Compare only’, ’Manually or ’Automatically’. The differences between these three choices are explained below: • Compare only : If you only want to compare the two projects and no merge is desired, then select the radio button ’Compare only’. This disables the merge functionality and only the differences between the two projects will be shown. • Manually : When this option is selected, you will later be asked to make assignments (to choose the source project data for common objects that are merged together). For this option, the target project can also be selected. or a three-way merge you cannot merge into the , either the or the project must be selected. • Automatically : When this option is selected, PowerFactory will attempt to automatically merge the three projects together, by automatically making data assignments. As for the Manually option, the target can be either the or project. Note that if ’conflicts’ are detected during an automatic merge, the CMT will automatically switch to manual mode. 318

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18.4. COMPARING AND MERGING PROJECTS 5. If using the Manually or Automatic options, you must choose the Assignment priority, by selecting an option from the Assign drop-down menu. This defines the default assignment in the CMT diff browser (or automatic merge) when PowerFactory identifies conflicts. For example, say the CMT identifies that the load called ’L1’ has an active power of 10 MW in , 12 MW in and 13 MW in . By choosing the option Automatically and favor 1st, the default assignment for ’L1’ would be and a power of 12 MW would be assigned to this load in the target project if you did not alter the assignment manually. 6. Press Execute to run the compare or merge. The CMT diff browser will appear (unless an automatic merge was selected and no conflicts were identified by PowerFactory ). Interpreting and using the diff browser is described in Section 18.4.5. Note: It is possible to assign user defined names for each of the compared projects to make it more convenient for remembering which project is being referred to by the CMT later on in the diff browser (see Section 18.4.5). For example, a user might wish to name two compared projects something like Master and User. Custom names can be implemented by typing the desired name in the as ... field in the CMT options dialogue shown in Figure 18.4.1. These user-defined names are limited to a maximum of ten characters.

18.4.4

Compare and Merge Tool Advanced Options

The Advanced Options page of the CMT shown is shown Figure 18.4.3.

Figure 18.4.3: Compare and Merge Tool Advanced Options

• Search correspondents for added objects – This option is only available for a three way merge and is enabled by default. If enabled then PowerFactory can automatically align two independently added objects as being the same object. This option can be useful when completing a comparison on projects where users have added the same object (same name) in each of their respective projects and you want to make sure PowerFactory identifies this object as being the same object. Note this option is only considered when the Identify correspondents always by name/rules option is also enabled. • Consider approval information – By default this option is disabled, which means that information in the object description page under Approval Information is not compared. For example, when this option is disabled if an objectŠs Approval status changes from Not Approved to Approved or vice versa, then this modification would not be registered by the CMT comparison engine. • ’Depth’

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CHAPTER 18. DATA MANAGEMENT – This option controls whether the CMT compares only the selected objects or also all objects contained within the compared objects. By default, Chosen and contained objects is enabled which means the CMT compares all objects within the selected comparison objects. This is generally the most appropriate option when merging projects. • Ignore differences < – This field controls the sensitivity of the comparison engine when comparing numerical parameters. If the difference between two numerical parameters is less than the value entered into this field, then the comparison will show the two values as equal =.

18.4.5

Compare and Merge Tool ’diff browser’

After the CMT options are set, and the button Execute is used to start the CMT comparison. Then the comparison and assignment results are presented in a data browser window (the CMT diff browser window shown in Figure 18.4.4). The diff browser is divided into three parts: • The Data Tree Window on the left; • The Comparison and Assignment Window on the right; and • The Output Window at the bottom. These features are explained in the following sections.

Figure 18.4.4: Compare and Merge Tool diff browser after a three-way merge

The Output Window The Output window displays reports from the context sensitive right-click menu and other error information. How to use the Comparison and Assignment Window In the CMT Comparison and Assignment Window, a list of the compared objects is shown. The window appears slightly different depending on whether a two way merge, a three way merge or a comparison has been completed. For instance, after a comparison, the Assigned from and Assignment Conflict columns are not shown. After a two-way merge, the columns with the project names will show and (or user-defined names), whereas after a three-way merge they will show and . A comparison result symbol, indicating the differences found for each object from the list, 320

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18.4. COMPARING AND MERGING PROJECTS is displayed in the columns and after a two-way merge and in columns and after a three-way merge. The possible combinations of these symbols are shown and explained in Tables 18.4.1 and 18.4.2. Base

1st

Comment Objects are identical in all projects A parameter of the object is modified in the project A parameter of the object is modified in project A new object in the project A new object in project Object removed in project Object removed in project Modified in both projects but the same modifications in both Modified in both projects but the modifications are different Modified in the project and removed in the project Modified in the project and removed in the project dentical object added in both projects Object added in both projects but parameters are different Object removed in both projects

Table 18.4.2: Possible results after a three-way comparison or merge

For a project merge (i.e. the Merge option was enabled in the command dialogue), the Assigned from must define the source project of the changes to implement in the target project. All listed objects must have an ’Assignment’. If you donŠt want to implement a certain change in the target; then the ’target’ project must be selected as the source. You should pay special attention to all results indicated with the ’conflict’ symbol . This symbol indicates that objects are different in both compared projects or that another error has occurred. In the case of conflicts, you must always indicate to PowerFactory the source project for the data. In a two-way merge, the only available sources for assignment are the (which is also the target) and . In a three-way merge, the possible sources are , and . The assignment can be made manually by double-clicking on the corresponding cell in the ’Assigned from’ column and selecting the desired source, or double-clicking the , or cell that you wish to assign. However, this task can be tedious in large projects where there are many differences. To rapidly assign many objects, the objects can be multi-selected and then Assign from ... or Assign with Children from ... can be selected from the context sensitive right-click menu. Base

1st

Comment The object has been removed in the project The object has been added to the project A parameter of the object has been modified in project The object is identical in both projects

Table 18.4.1: Possible results after a two way comparison or merge

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CHAPTER 18. DATA MANAGEMENT After the assignment of all the objects, the projects can be merged by pressing the Merge button. The changes are then automatically implemented in the target project. Note: The Comparison and Assignment Window always shows the selected object in the Data Tree Window in the first row.

Data Tree Window The window on the left side of Figure 18.4.4 shows the Data Tree Window, which is similar in appearance to the data manager tree. This window shows the compared objects in a normal project tree structure. At each level of the tree, there is an indication on the right showing the status of the comparison of the contained objects (and the object itself). The legend for the comparison indication is shown in Table 18.4.3. Icon/Text

Mixed///

Bold red font

Meaning Assignments/Comparison is okay Conflicts exist The text indicates the assignments within by indicating the assigned project. If assignments within are from multiple different sources, then ’Mixed’ will show. Assignments missing three way merge - information will be lost during the merge two way merge information could be lost during the merge

Table 18.4.3: Data Tree Window Legend

Diff Browser Toolbar As previously mentioned, the objects displayed in the CMT window can be sorted and organized by the toolbar as shown in Figure 18.4.5. The available buttons are explained in this section.

Figure 18.4.5: Compare and Merge Tool ’diff browser’ toolbar

Modifications to be shown The Modifications to be shown drop-down menu allows the results in the comparison windows to be filtered according to their comparison status. Possible filter options for a three way comparison are: • All objects • All modifications (default) • All modifications in (show all modifications, additions and deletions in the project) • All modifications in (show all modifications, additions and deletions in the project) • All modifications in both (show only those objects which exist in both projects and have been modified in both projects)

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18.4. COMPARING AND MERGING PROJECTS • All modifications in both but different (show only those objects which exist in both projects and have been modified in both projects to different values) • Added in (show only objects added in the project) • Modified in (show only objects modified in the project) • Deleted in (show only objects deleted in the project) • Added in (show only objects added in the project) • Modified in (show only objects modified in the project) • Deleted in (show only objects deleted in the project) The following options are available for a two way comparison: • All objects • All modifications • Added in • Modified in • Deleted in Only one option can be selected at a time. Show all objects inside chosen object This button will list all compared objects and also all contained objects (at every level of the tree). Show graphical elements Pressing this button will prevent graphical differences from appearing in the comparison window. Because graphical changes often occur, and can often be trivial, for example a slight adjustment to the x-axis position of an object, this button is extremely useful for organizing the data. Detail mode and Detail mode class select identical to their function in the data manager.

The functionality of these two buttons is

Show only not assigned Filters the display to show only objects not yet assigned. This filter is only available when the merge option is used. By default all assigned and unassigned objects are displayed. Show only Objects with assignment conflicts Only objects with assignment conflicts are displayed. This filter is only available when the merge option is used. By default objects with and without assignment conflicts are displayed. Group dependent objects If this option is enabled, dependent objects are listed indented underneath each listed comparison object. A dependent object is defined as an object that is referenced by another object. For example, a line type (TypLne) is a dependent object of a Line Element (ElmLne), likewise the cubicles that connect the Line Element to a terminal. If the objects are grouped and not filtered otherwise, every object has to be listed at least once but can be listed several times as a dependency. Non-primary objects (such as graphical elements) are only listed separately if they are not listed as a dependency for another object. Dependent objects are not filtered. By default, the grouping of dependent objects is not displayed because this type of display can quickly expand to become unusable because in a typical project there are many dependencies. Diff window right-click menu options DIgSILENT PowerFactory 15, User Manual

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CHAPTER 18. DATA MANAGEMENT A context sensitive menu can be activating by right-clicking a cell or object in the tree window or the comparison and assignment window. The following options are available: Show Object ... A project selection window will appear so that you can show specific object data. After you choose the reference project, the dialogue of the selected object is then displayed. The displayed dialogue is read-only. Output Modification Details This prints a report to the output window showing the details of the differences for the selected objects. The format of the report is a ASCII table with the modified parameters as rows and the parameter values in each compared project as columns. The date and time of the last modification along with the database user who made the last change are always shown in the first two rows. Output Non-OPD Modification Details This option is similar to the Output Modification Details option, but it only shows the modifications that are not classed as Operational Data. Align Manually This option allows the compared objects to be realigned across the compared projects. What this means is that disparate objects can instead be compared directly. This could be useful for example when two different users have added an object to their derived projects but each has given it a slightly different name, even though the objects are representing the same ’real world’ object. The CMT would see these objects as different objects by default. In this case, the data administrator might wish to tell PowerFactory that these two different objects are the same object and this can be completed using the Align Manually function. Ignore Missing References For every compared object missing references can be optionally ignored. The assignment check then does not check the references of the object. Missing references can also be considered again by using the Consider Missing References option. By default missing references are not ignored. Set Marker in Tree A right-click in the data tree window allows you to set a marker within the data tree. This behaves somewhat like a bookmark and you can return to this point in the data tree at any time by using the Jump to Marker ”...” in Tree. Note it is only possible to set one marker at a time - setting a new marker will automatically over-write the last marker. Diff window buttons The various diff window buttons as highlighted in Figure 18.4.6 will now be explained.

Figure 18.4.6: Compare and Merge Tool ’Diff window’ with buttons highlighted

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18.5. HOW TO UPDATE A PROJECT Check This button checks that all assignments are okay. The following conflicts are checked for all compared objects: • Missing assignment; • Missing parent (Parent object of an assigned object will not exist in the target after merge.) • Missing reference (Referenced object of an assigned object will not exist in the target after merge.) All conflicts are printed as errors to the output window of the CMT. Conflicts are listed in groups icon in the data tree and comparison and assignment window. and with the Recompare After a realignment, it is necessary to run the CMT again using this button to update the comparison results. Merge The merge procedure updates the target by copying objects or parameters or deleting objects according to the assignments. Before the merge procedure is started an assignment check is done. The merge procedure is cancelled if the check detects conflicts. If no conflicts are detected, the Diff Browser is closed and then the merge procedure is started. After the merge procedure is complete all data collected by the CMT is discarded. Info The ’Info’ dialogue called by the Info button shows more information about the comparison: • database path of the top level projects/objects that are being compared; • target for merge (only if merge option is active); • selected comparison options; • number of objects compared; • number of objects modified; and • number of objects with conflicts (only if merge option is active).

18.5

How to update a Project

There are two common procedures that users and data administrators need to complete when working with Master Projects and other user projects that are derived from versions of this Master project: • Updating a derived project with information from a new version; and • Updating a Master Project with information from a derived project. This section explains these two procedures and also tips for working with the CMT.

18.5.1

Updating a Derived Project from a new Version

When a derived project is activated after a new version of the Base project has been created (provided that the flag Notify users of derived projects was checked when the version was created and that the derived project option Disable notification at activation is unchecked), then the user will be presented with the dialogue shown in Figure 18.5.1.

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Figure 18.5.1: New Version available - dialogue box

The options offered in the notification dialogue are: Merge new version with derived project and • PowerFactory automatically generates a temporary copy derived of the new version and executes a 3-way comparison with the base version of the userŠs project (as the Base), the derived project (as ) and the temporary copy (as and target). In the case of a conflict, one of the following actions will be taken: • favor none: The CMT diff browser is displayed, and the user can then resolve the conflict(s) by defining how the changes should be assigned. • favor derived project: Conflicts are resolved automatically by favouring the userŠs modifications, thereby discarding modifications in the Base. • favor new version: Conflicts are resolved automatically by favouring the BaseŠs modifications, thereby discarding the userŠs modifications. Get new version and discard modifications in derived project The derived project is automatically replaced by the new version. All user modifications will be lost. Merge manually Use the CMT to merge the modifications manually. The results of the comparison are displayed in a CMT diff browser, where the user defines how the changes should be assigned. After these assignments have been defined, the new version and the derived project are merged to the temporary copy, when the user clicks on the Merge button. The derived project is then automatically replaced by the temporary copy (now containing information from the new version), which is deleted. Notify me again in... The user enters the desired time for re-notification, and the derived project is activated according to how it was left in the previous session. The notification is deactivated for the indicated number of days. Note: In a multi-user environment, updated versions of the Base project can be released regularly and the user will often be presented with the new version notification in Figure 18.5.1. In many cases, the user will not want to apply the updated version because they will be in the middle of a project or other calculation and don’t want to risk corrupting or changing their results. Therefore, the option Notify me again in... is the appropriate choice because it will leave the userŠs project unchanged.

If the Cancel button is used, the project is activated as it was left in the previous session. The notification will appear following the next activation. An alternative way to manually initiate the above procedure is to right-click the derived project and select the option Merge from base project. This feature is only possible with deactivated projects.

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18.6. SHARING PROJECTS

18.5.2

Updating a base project from a Derived Project

Changes implemented in derived projects can also be merged to the base project. In this case, the option Merge to base project must be selected from the context-sensitive menu available by rightclicking on the derived project. As in previous cases, the CMT is started and you can manually resolve conflicts using the diff browser.

18.5.3

Tips for working with the Compare and Merge Tool

One of the most common uses of the CMT is for merging changes made by users to their derived projects back into the Master project to create an updated version for all users. Such a task is often done by the data administrator. For this task it can help to follow the steps as outlined below: 1. Check the user’s modifications with a 2-way merge (derived vs. base; What changes were done? Are all changes intended? Modifications which were made by mistake should be corrected in the user’s derived model before continuing with the merge procedure.). The check of the modifications should be done by the user and the data administrator. 2. The data administrator creates a new derived project based on the most recent version of the ’Master’ model. 3. A three way merge is done, selecting the version on which the user’s derived project is based on as ’Base’, the derived project created in the previous step as and the user’s derived project as . The changes are merged into (target). 4. The resulting model is then validated. Conflicts which could not be solved automatically by the CMT are corrected manually. 5. The validated model (derived project in data administrator account) is merged to the base model by using the context sensitive menu entry Merge to Base Project. This will not cause problems if the master model has not been changed since deriving the model in step 2. 6. A new version is created by the data administrator and the users informed. Note: The Compare and Merge Tool can be used to compare any kind of object within a PowerFactory project. The functionality and procedure to follow is similar to that explained in this section for project comparison and merging.

18.6

Sharing Projects

In PowerFactory , any project can be shared with other users according to the rules defined by its owner. Projects are shared to groups of users and not directly to individuals. Therefore, users must be part of a group (created and managed by the data Administrator) in order to access shared projects. Depending on the access level that the owner assigns to a group, other users can get: • read-only access to the shared project, which allows the copying of objects and the creation of derived projects from versions within the shared project; • read-write access; This allows users full control over all objects within the project. • Full access. Full access allows the user to modify the sharing properties and create versions. Each access level includes the rights of the lower levels. To share a project: DIgSILENT PowerFactory 15, User Manual

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CHAPTER 18. DATA MANAGEMENT 1. Open the project dialogue by right-clicking the project name and selecting the option Edit. 2. Select the Sharing tab; 3. Right-click within the Groups or Sharing access level columns on the right side of the Sharing information table to insert (or append) a row(s); 4. Double-click the Groups cell of the new line and select the group with whom the project is shared using the data browser; 5. Double-click on the Sharing access level to select the desired access level. A shared project is marked with the

symbol in the Data Manager.

For information regarding users groups and the data administrator, please refer to Chapter 6 (User Accounts and User Groups).

18.7

Database archiving

An archiving function for decreasing the used database storage space and increasing performance of large multi-user databases is available. Older projects that are currently not used but still important for a possibly use in the future can now be archived. In multi-user database environments, the user can easily send projects to the archive folder by executing the Archive command in the context sensitive right mouse button menu of each project item and selecting “Archive" The archived projects are exported from database and stored in a separate folder (Archived Projects) for long term storing. The user increases thus system performance and the speed of general database operations (e.g. project loading/closing). All information regarding the initial project location is also saved allowing the user to restore projects in the exact location it originated from. Projects can be accessed back and loaded into the active database by executing the “Restore" command in the context sensitive right mouse button menu of each project.

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Chapter 19

The DIgSILENT Programming Language - DPL 19.1

Introduction

The DIgSILENT Programming Language DPL serves the purpose of offering an interface for automating tasks in the PowerFactory program. The DPL method distinguishes itself from the command batch method in several aspects: • DPL offers decision and flow commands • DPL offers the definition and use of user-defined variables • DPL has a flexible interface for input-output and for accessing objects • DPL offers mathematical expressions The DPL adds a new dimension to the DIgSILENT PowerFactory program by allowing the creation of new calculation functions. Such user-defined calculation commands can be used in all areas of power system analysis, such as • Network optimizing • Cable-sizing • Protection coordination • Stability analysis • Parametric sweep analysis • Contingency analysis • etc. Such new calculation functions are written as program scripts which may use • Flow commands like “if-then-else" and “do-while" • PowerFactory commands (i.e. load-flow or short-circuit commands) • Input and output routines DIgSILENT PowerFactory 15, User Manual

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CHAPTER 19. THE DIGSILENT PROGRAMMING LANGUAGE - DPL • Mathematical expressions • PowerFactory object procedure calls • Subroutine calls

19.2

The Principle Structure of a DPL Command

The principle Structure of a DPL script is shown in Figure 19.2.1.

Figure 19.2.1: Principle of a DPL command

The DPL command object ComDpl is the central element, which is connecting different parameter, variables or objects to various functions or internal elements and then puts out results or changes parameters. As the input to the script can be predefined input parameters, single objects from the single line diagram or the database or a set of objects/elements, which are then stored inside a so called “General Selection". These input information can then be evaluated using functions and internal variables inside the script. Also internal objects can be used and executed, like • a calculation command, i.e. ComLdf, ComSim, etc., especially defined with certain calculation options • subscripts also released in DPL • filter sets, which can be executed during the operation of the script Thus the DPL script will run a series of operation and start calculation or other function inside the script. It will always communicate with the database and will store changed settings, parameters or results directly in the database objects. There is nearly no object inside the active project, which can not be accessed or altered.

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19.3. THE DPL COMMAND OBJECT During or at the end of the execution of the DPL script, the results can be outputted or parameters of elements my be changed. There is the possibility to execute a predefined output command ComSh or to define own outputs with the DPL commands available.

19.3

The DPL Command Object

The DPL command object ComDpl holds a reference to a remote DPL command when it is not a root command. The example depicted in Figure 19.3.1 is apparently a referring command, since its “DPL script" reference is set to the remote command ∖ Library∖ DPL Commands∖ CheckVLoading.

Figure 19.3.1: A DPL command

• A root command has its own script on the “script" page of the dialogue. • A referring command uses the script of the remote DPL command.

19.3.1

Creating a new DPL Command

A DPL Command ComDpl can be created by using the New Object ( ) icon in the toolbar of the data manager and selecting DPL Command and more. Then press OK and a new DPL command is created. The dialogue is now shown and the parameters, objects and the script can now be specified. This dialogue is also opened by double-clicking a DPL script, by selecting Edit from the context sensitive menu or by selecting the script from the list when pressing the icon .

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19.3.2

Defining a DPL Commands Set

The DPL command holds a reference to a selection of objects (General Selection). At first this general selection is empty, but there are several ways to define a special set of object used in the DPL command. This “DPL Commands Set" (SetSelect) can be specified through: • Select one or more elements in the single line diagram. Then right-click the selection (one of the selected elements) and choose the option Define. . . → DPL Commands Set. . . from the context sensitive menu. • It is also possible to select several elements in the data manager. Right-click the selection and choose the option Define. . . → DPL Commands Set. . . from the context sensitive menu.

19.3.3

Executing a DPL Command

To execute a DPL command or to access the dialogue of a script, the icon will pop up a list of available DPL scripts from the global and local library.

can be activated. This

The easiest way to start a DPL command AND define a selection for it is • To select one or more elements in the single line diagram or in the data manager and then rightclick the selection. • Choose the option Execute DPL Scripts from the context sensitive menu. • Then select a DPL script from the list. This list will show DPL scripts from the global as well as from the local library. • Select a DPL script, insert/change the variables and then press the button Execute In this way the selection is combined into a DPL Commands Set and the set is automatically selected for the script chosen. Only one single DPL command set is valid at a time for all DPL scripts. This means that setting the DPL command set in one DPL command dialogue, will change the DPL command set for all DPL commands in the database. Note: To choose different sets for various DPL scripts you can either use different selection object SetSelect like the “General Set". Or new DPL command sets can be created and selected inside the active study case. This is done by pressing , selecting “other" and the element Set (SetSelect) and then selecting the set type.

The interface section Input Parameters is used to define variables that are accessible from outside the DPL command itself. DPL commands that call other DPL commands as subroutines, may use and change the values of the interface variables of these DPL subroutines. The list of External Objects is used to execute the DPL command for specific objects. A DPL command that, for example, searches the set of lines for which a short-circuit causes too deep a voltage dip at a specific busbar, would access that specific busbar as an external object. Performing the same command for another busbar would then only require setting the external object to the other busbar.

19.3.4

DPL Advanced Options

On the Advanced Options page a Remote script can be selected, which is then used by this script instead of a local defined script on the next page Script. This is a so called “referring command". The “root command" as described above in the example uses the local defined script. 332

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19.4. THE DPL SCRIPT EDITOR Also there can be Result parameters defined. These parameters are results from the script and they are stored inside the result object. Hence it is possible to access them through the variable monitor and display them in a plot.

19.3.5

DPL Script Page

The most important part of a DPL root command is of course the actual DPL program script. That script is written on the Script page of a DPL root command dialogue, if no Remote script is selected. On this page the DPL code of a already defined script is shown and/or new command lines can be inserted for modifying this script or writing a new script. The available commands and the DPL language are described in the following sections. The edited program code also features a highlighting specially suited for handling DPL scripts.

19.4

The DPL Script Editor

There is also an own editor available for conveniently writing a DPL script. To activate this editor press on the bottom side of the Script page of a DPL command dialogue. the icon Now a new window will be opened in PowerFactory. Here the script can be written in a very convenient way similar to the programming language C++. The highlighting will be activated automatically. There are several tools which can be used in this editor: With this icon Edit Object the edit dialogue of the script is opened and the user can Check the modified script for errors or one can Execute it. The script inside the editor and in the dialogue are synchronized each time the script is saved or edited in the dialogue. If this Disconnect icon is pressed, the scripts will not be synchronized anymore. With the search icon the user can activate a Find, a Replace or also a Go To function inside the editor. With the search next icon find/replace/go to the next matching word. With the search previous icon find/replace/go to the previous matching word. With the these icons bookmarks can be set in the editor. Also jump from one bookmark to the next or previous as well as clear all bookmarks When finished editing, press the icon and the script will be synchronized with the main dialogue. One can also jump to the main graphics board by selecting the option Window → Graphic. . . from the main menu.

19.5

The DPL Script Language

The DPL script language uses a syntax quite similar to the C++ programming language. This type of language is intuitive, easy to read, and easy to learn. The basic command set has been kept as small as possible. The syntax can be divided into the following parts: DIgSILENT PowerFactory 15, User Manual

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CHAPTER 19. THE DIGSILENT PROGRAMMING LANGUAGE - DPL • variable definitions • assignments and expressions • program flow instructions • method calls The statements in a DPL script are separated by semicolons. Statements are grouped together by braces. Example: statement1; statement2; if (condition) { groupstatement1; groupstatement2; }

19.5.1

Variable Definitions

DPL uses the following internal parameter types • double, a 15 digits real number • int, an integer number • string, a string • object, a reference to a PowerFactory object • set, a container of object Vectors and Matrices are available as external objects. The syntax for defining variables is as follows: [VARDEF] = [TYPE] varname, varname, ..., varname; [TYPE] = double | int | object | set All parameter declarations must be given together in the top first lines of the DPL script. The semicolon is obligatory. Examples: double int string object set

19.5.2

Losses, Length, Pgen; NrOfBreakers, i, j; txt1, nm1, nm2; O1, O2, BestSwitchToOpen; AllSwitches, AllBars;

Constant parameters

DPL uses constant parameters which cannot be changed. It is therefore not accepted to assign a value to these variables. Doing so will lead to an error message. The following constants variables are defined in the DPL syntax: 334

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19.5. THE DPL SCRIPT LANGUAGE SEL is the general DPL selection NULL is the “null" object this is the DPL command itself Besides these global constants, all internal and external objects are constant too.

19.5.3

Assignments and Expressions

The following syntax is used to assign a value to a variable: variable = expression variable += expression variable -= expression

The add-assignment “+=" adds the right side value to the variable and the subtract-assignment “-=" subtracts the right-side value. Examples: double x,y;x = 0.5*pi(); y = sin(x); x += y; y -= x;

19.5.4

! ! ! !

x y x y

now now now now

equals equals equals equals

1.5708 1.0 2.5708 -1.5708

Standard Functions

The following operators and functions are available: • Arithmetic operators: +, -, * , / • Standard functions ( all trigonometric functions based on radians (RAD))

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CHAPTER 19. THE DIGSILENT PROGRAMMING LANGUAGE - DPL function sin(x) cos(x) tan(x) asin(x) acos(x) atan(x) sinh(x) cosh(x) tanh(x) exp(x) ln(x) log(x) sqrt(x) sqr(x) pow (x,y) abs(x) min(x,y) max(x,y) modulo(x,y) trunc(x) frac(x) round(x) ceil(x) floor(x)

description sine cosine tangent arcsine arccosine arctangent hyperbolic sine hyperbolic cosine hyperbolic tangent exponential value natural logarithm log10 square root power of 2 power of y absolute value smaller value larger value remainder of x/y integral part fractional part closest integer smallest larger integer largest smaller integer

example sin(1.2)=0.93203 cos(1.2)=0.36236 tan(1.2)=2.57215 asin(0.93203)=1.2 acos(0.36236)=1.2 atan(2.57215)=1.2 sinh(1.5708)=2.3013 cosh(1.5708)=2.5092 tanh(0.7616)=1.0000 exp(1.0)=2.718281 ln(2.718281)=1.0 log(100)=2 sqrt(9.5)=3.0822 sqr(3.0822)=9.5 pow(2.5, 3.4)=22.5422 abs(-2.34)=2.34 min(6.4, 1.5)=1.5 max(6.4, 1.5)=6.4 modulo(15.6,3.4)=2 trunc(-4.58823)=-4.0000 frac(-4.58823)=-0.58823 round(1.65)=2.000 ceil(1.15)=2.000 floor(1.78)=1.000

Table 19.5.1: DPL Standard Functions • Constants: pi() twopi() e()

pi 2 pi e

Table 19.5.2: DPL Internal Constants

19.5.5

Program Flow Instructions

The following flow commands are available. if ( [boolexpr] ) [statlist] if ( [boolexpr] ) [statlist] else [statlist] do [statlist] while ( [boolexpr] ) while ( [boolexpr] ) [statlist] for ( statement ; [boolexpr] ; statement ) [statlist]

in which [boolexpr] = expression [boolcomp] expression [boolcomp] = "" | "=" | ">=" | ">=" | "" [statlist] = statement; | { statement; [statlist] }

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19.5. THE DPL SCRIPT LANGUAGE • Binary operators: “.and." | “.or." | “.nand." | “.nor." | “.eor." • Parentheses: {logical expression} Examples: if (a=b* c) { a = O:dline; c = c + delta; } if (.not.a.and.b3) { err = Ldf.Execute(); if (err) { Ldf:iopt_lev = 1; err = Ldf.Execute(); Ldf:iopt_lev = 0; } } for (i = 0; i < 10; i = i+1){ x = x + i; } for (o=s.First(); o; o=s.Next()) { o.ShowFullName(); }

Break and Continue The loop statements “do-while" and “while-do" may contain “break" and “continue" commands. The “break" and “continue" commands may not appear outside a loop statement. The “break" command terminates the smallest enclosing “do-while" or “while-do" statement. The execution of the DPL script will continue with the first command following the loop statement. The “continue" command skips the execution of the following statements in the smallest enclosing “dowhile" or “while-do" statement. The execution of the DPL script is continued with the evaluation of the boolean expression of the loop statement. The loop statement list will be executed again when the expression evaluates to TRUE. Otherwise the loop statement is ended and the execution will continue with the first command following the loop statement. Example: O1 = S1.First(); while (O1) { O1.Open(); err = Ldf.Execute(); if (err) { ! skip this one O1 = S1.Next; continue; } DIgSILENT PowerFactory 15, User Manual

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CHAPTER 19. THE DIGSILENT PROGRAMMING LANGUAGE - DPL O2 = S2.First(); AllOk = 1; DoReport(0); !reset while (O2) { err = Ldf.Execute(); if (err) { ! do not continue AllOk = 0; break; } else { DoReport(1); ! add } O2 = S2.Next(); } if (AllOk) { DoReport(2); ! report } O1 = S1.Next();}

19.5.6

Input and Output

The “input" command asks the user to enter a value. input(var, string); The input command will pop up a window with the string and an input line on which the user may enter a value. The value will be assigned to the variable “var". The “output" command writes a line of text to the output window. output(string); The string may contain “=-" signs, followed by a variable name. The variable name will then be replaced by the variable’s value. Example: input(diameter, 'enter diameter'); output('the entered value=diameter'); The example results in the pop up of a window as depicted in Figure 19.5.1.

Figure 19.5.1: The input window

The following text will appear in the output window: DIgSI/dpl - the entered value=12.3400 338

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19.6. ACCESS TO OTHER OBJECTS The output command is considered obsolete and has been replaced by the more versatile “printf" and “sprintf" functions. Please see the DPL reference for detailed information.

19.6

Access to Other Objects

With the syntax for the parameter definitions, program flow and the input and output, it is already possible to create a small program. However, such a script would not be able to use or manipulate variables of “external" objects. It would not be possible, for instance, to write a script that replaces a specific line by possibly better alternatives, in order to select the best line type. Such a script must be able to access specific objects (the specific line) and specific sets of objects (the set of alternative line types). The DPL language has several methods with which the database objects and their parameters become available in the DPL script: • The most direct method is to create an object, or a reference to an object, in the DPL command folder itself. Such an object is directly available as “object" variable in the script. The variable name is the name of the object in the database. • The DPL command set may be used. This method is only useful when the order in which the objects are accessed is not important. The DPL command set is automatically filled when a selection of elements is right-clicked in either the single line graphic or the data manager and the option Execute DPL Script is selected. • The list of external objects is mainly used when a script should be executed for specific objects or selections. The list of external objects is nothing more than a list of “aliases". The external object list is used to select specific objects for each alias, prior to the execution of the script.

19.6.1

Object Variables and Methods

If a database object is known to the DPL command, then all its methods may be called, and all its variables are available. For example, if we want to change a load-flow command in order to force an asymmetrical load-flow calculation, we may alter the parameter “iopt_net". This is done by using an assignment: Ldf:iopt_net = 1; !

force unbalanced

In this example, the load-flow objects is known as the objects variable “Ldf". The general syntax for a parameter of a database object is objectname:parametername In the same way, it is possible to get a value from a database object, for instance a result from the load-flow calculations. One of such a result is the loading of a line object, which is stored in the variable “c:loading". The following example performs the unbalanced load-flow and reports the line loading. Example 00. 01. 02. 03. 04. 05. 06. 07. 08.

int error; double loading; Ldf:iopt_net = 1; ! force unbalanced error = Ldf.Execute(); ! execute load-flow if (error) { exit(); } else { loading = Line:c:loading; ! get line loading output('loading=loading'); ! report line loading

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}

This examples is very primitive but it shows the basic methods for accessing database objects and their parameters.

19.7

Access to Locally Stored Objects

Locally stored objects (also called “internal objects") can be accessed directly. They are known in the DPL script under their own name, which therefore must be a valid DPL variable name. It will not be possible to access an internal object which name is “My Load-flow\∼{}1* ", for instance. Internal objects may also be references to objects which are stored elsewhere. The DPL command des not distinguish between internal objects and internal references to objects. An example is shown in Figure 19.7.1, where a DPL script is shown on the left which has a load-flow command and a reference to a line in its contents folder on the right.

Figure 19.7.1: DPL contents

The example DPL script may now access these objects directly, as the objects “Ldf" and “Line". In the following example, the object “Ldf", which is a load-flow command, is used in line 01 to perform a load-flow. 00. 01. 02. 03. 04. 05.

int error; error = Ldf.Execute(); if (error) { output('Load-flow command returns an error'); exit(); }

In line 01, a load-flow is calculated by calling the method “Execute()" of the load-flow command. The details of the load-flow command, such as the choice between a balanced single phase or an unbalanced three phase load-flow calculation, is made by editing the object “Ldf" in the database. Many other objects in the database have methods which can be called from a DPL script. The DPL contents are also used to include DPL scripts into other scripts and thus to create DPL “subroutines".

19.8

Accessing the General Selection

Accessing database objects by storing them or a reference to them in the DPL command would create a problem if many objects have to be accessed, for instance if the line with the highest loading is to be found. It would be impractical to create a reference to each and every line. A more elegant way would be to use the DPL global selection and fill it with all lines. The data manager offers several ways in which to fill this object DPL Command Set with little effort. The selection may

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19.9. ACCESSING EXTERNAL OBJECTS then be used to access each line indirectly by a DPL “object" variable. In this way, a loop is created which is performing the search for the highest loading. This is shown in the following example. Example 00. int error; 01. double max; 02. object O, Omax; 03. set S; 04. 05. error = Ldf.Execute(); 06. if (error) exit(); 07. 08. S = SEL.AllLines(); 09. Omax = S.First(); 10. if (Omax) { 11. max = Omax:c:loading; 12. } else { 13. output('No lines found in selection'); 14. exit(); 15. } 16. O = S.Next(); 17. while (O) { 18. if (O:c:loading>max) { 19. max = O:c:loading; 20. Omax = O; 21. } 22. O = S.Next(); 23. } 24. output('max loading=max for line'); 25. Omax.ShowFullName();

!

execute a load-flow

!

exit on error

! get all selected lines ! get first line !

initialize maximum

!

no lines:

! !

get next line while more lines

exit

! update maximum ! update max loaded line

!output results

The object SEL used in line 08 is the reserved object variable which equals the General Selection in the DPL command dialogue. The SEL object is available in all DPL scripts at all times and only one single “General Selection" object is valid at a time for all DPL scripts. This means that setting the General Selection in the one DPL command dialogue, will change it for all other DPL commands too. The method “AllLines()" in line 08 will return a set of all lines found in the general selection. This set is assigned to the variable “S". The lines are now accessed one by one by using the set methods “First()" and “Next()" in line 09, 16 and 22. The line with the highest loading is kept in the variable “Omax". The name and database location of this line is written to the output window at the end of the script by calling “ShowFullName()".

19.9

Accessing External Objects

The DPL contents make it possible to access external object in the DPL script. The special general selection object (“SEL") is used to give all DPL functions and their subroutines access to a central selection of objects. i.e. the DPL Command Set. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 19. THE DIGSILENT PROGRAMMING LANGUAGE - DPL Although flexible, this method would create problems if more than one specific object should be accessed in the script. By creating references to those objects in the DPL command itself, the DPL command would become specific to the current calculation case. Gathering the objects in the general selection would create the problem of selecting the correct object. To prevent the creation of calculation-specific DPL commands, it is recommended practice to reserve the DPL contents for all objects that really “belong" to the DPL script and which are thus independent on where and how the script is used. Good examples are load-flow and short-circuit commands, or the vector and matrix objects that the DPL command uses for its computations. If a DPL script must access a database object dependent on where and how the DPL script is used, an “External Object" must be added to the external object list in the DPL root command. Such an external object is a named reference to an external database object. The external object is referred to by that name. Changing the object is then a matter of selecting another object. In Figure 19.9.1, an example of an external object is given. This external object may be referred to in the DPL script by the name “Bar1", as is shown in the example.

Figure 19.9.1: DPL external object table

Example: sagdepth = Bar1:u;

19.10

Remote Scripts and DPL Command Libraries

To understand the DPL philosophy and the resulting hierarchical structure of DPL scripts, the following is important to understand:

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19.10. REMOTE SCRIPTS AND DPL COMMAND LIBRARIES • A DPL command either executes its own script or the script of another, remote, DPL command. In the first case, the DPL command is called a “root command" and the script is called a “local script". In the second case, the DPL command is called a “referring" command and the script is called a “remote script". • A root command may define interface variables that are accessible from outside the script and which are used to define default values. • Each root command may define one or more external objects. External object are used to make a DPL command run with specific power system objects, selections, commands, etc. • A referring command may overrule all default interface values and all selected external objects of the remote command. • Each DPL command can be called as a subroutine by other DPL commands. The use of remote scripts, external objects and interface variables makes it possible to create generic DPL commands, which may be used with different settings in many different projects and study cases. The easiest way to develop a new DPL command is to create a new ComDpl in the currently active study case and to write the script directly in that DPL object. In such a way, a DPL “root command" is made. If this root command needs DPL subroutines, then one or more DPL command objects may be created in its contents. Each of these subroutines will normally also be written as root functions. The newly written DPL command with its subroutines may be tested and used in the currently active study case. However, it cannot be executed when another study case is active. In order to use the DPL command in other study cases, or even in other projects, one would have to copy the DPL command and its contents. This, however, would make it impossible to alter the DPL command without having to alter all its copies. The solution is in the use of “remote scripts". The procedure to create and use remote scripts is described as follows. Suppose a new DPL command has been created and tested in the currently active study case. This DPL command can now be stored in a save place making it possible to use it in other study cases and projects. This is done by the following steps: • Copy the DPL command to a library folder. This will also copy the contents of the DPL command, i.e. with all it’s DPL subroutines and other locally stored objects. • “Generalize" the copied DPL command by resetting all project specific external objects. Set all interface variable values to their default values. To avoid deleting a part of the DPL command, make sure that if any of the DPL (sub)commands refers to a remote script, all those remote scripts are also stored in the library folder. • Activate another study case. • Create a new DPL command object (ComDPL) in the active study case. • Set the “DPL script" reference to the copied DPL command. • Select the required external objects. • Optionally change the default values of the interface variables • Press the Check button to check the DPL script The Check or Execute button will copy all parts of the remote script in the library that are needed for execution. This includes all subroutines, which will also refer to remote scripts, all command objects, and all other objects. Some classes objects are copied as reference, other classes are copied completely. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 19. THE DIGSILENT PROGRAMMING LANGUAGE - DPL The new DPL command does not contain a script, but executes the remote script. For the execution itself, this does not make a change. However, more than one DPL command may now refer to the same remote script. Changing the remote script, or any of its local objects or sub-commands, will now change the execution of all DPL commands that refer to it.

19.10.1

Subroutines and Calling Conventions

A DPL command object may be included in the contents of another DPL command. In that case, the included DPL “subroutine" may be called in the script of the enclosing DPL command. In principle, this is not different from calling, for example, a load-flow command from a DPL script. As with most other command objects, the DPL command only has one method: int Execute() ; executes the DPL script. The difference is that each DPL subroutine has different interface parameters, which may be changed by the calling command. These interface parameters can also be set directly at calling time, by providing one or more calling arguments. These calling arguments are assigned to the interface parameters in order of appearance. The following example illustrates this. Suppose we have a DPL sub-command “Sub1" with the interface section as depicted in Figure 19.10.1.

Figure 19.10.1: Interface section of subroutine

The calling command may then use, for example: ! set the parameters: Sub1:step = 5.0; Sub1:Line = MyLine; Sub1:Outages = MySelection; ! execute the subroutine: 344

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19.11. DPL FUNCTIONS AND SUBROUTINES error = Sub1.Execute();

However, using calling arguments, we may also write: ! execute the subroutine: error = Sub1.Execute(5.0, MyLine, MySelection);

19.11

DPL Functions and Subroutines

The DPL syntax is very small because it mainly serves the purpose of basic operations like simple calculations, if-then-else selections, do-while loops, etc.. The strength of the DPL language is the possibility to call functions and to create subroutines. A function which can be called by a DPL command is called a “method". Four types of methods are distinguished: Internal methods These are the build-in methods of the DPL command. They can always be called. Set methods These methods are available for the DPL “set" variables. Object methods These methods are available for the DPL “object" variables. External methods These are the methods which are available for certain external PowerFactory objects, such as the load-flow command, the line object, the asynchronous machine, etc. Please see the Appendix D DPL Reference for a description of these functions including implementation examples.

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Chapter 20

PowerFactory Interfaces 20.1

Introduction

PowerFactory supports a wide set of interfaces. Depending on the specific data exchange task the user may select the appropriate interface. The interfaces are divided as follows: • Interfaces for the exchange of data according to DIgSILENT specific formats: – DGS – StationWare (DIgSILENT GmbH trademark) • Interfaces for the exchange of data using proprietary formats: – PSS/E – NEPLAN – MATLAB – INTEGRAL • Interfaces for the exchange of data according to standardized formats: – UCTE-DEF – CIM – OPC • Interfaces for remote control of PowerFactory – API – Python The above mentioned interfaces are explained in the following sections.

20.2

DGS Interface

DGS (DIgSILENT) is PowerFactory ’s standard bi-directional interface specifically designed for bulk data exchange with other applications such as GIS and SCADA, and, for example, for exporting calculation results to produce Crystal Reports, or to interchange data with any other software package. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 20. POWERFACTORY INTERFACES Figure 20.2.1 illustrates the integration of a GIS (Graphical Information System) or SCADA (Supervisory Control And Data Acquisition) with PowerFactory via the DGS interface Here, PowerFactory can be configured either in engine or normal mode. When used in engine mode, PowerFactory imports via DGS the topological and library data (types), as well as operational information. Once a calculation has been carried out (for example a load flow or short circuit), the results are exported back so they are displayed in the original application; which in this example relates to the SCADA or GIS application. The difference with PowerFactory running in normal mode (see right section of Figure 20.2.1) is that, besides the importing of data mentioned previously, the graphical information (single line graphics) is additionally imported, meaning therefore that the results can be displayed directly in PowerFactory. In this case, the exporting back of the results to the original application would be optional.

Figure 20.2.1: DGS - GIS/SCADA Integration

Although the complete set of data can be imported in PowerFactory every time a modification has been made in the original application, this procedure would be impractical. The typical approach in such situations would be to import the complete set of data only once and afterwards have incremental updates.

20.2.1

DGS Interface Typical Applications

Typical applications of the DGS Interface are the following: • Importing to PowerFactory – Data Import/Update into PowerFactory from external data sources such as GIS (Network Equipment), SCADA (Operational Data) and billing/metering systems (Load Data) in order to perform calculations. • Exporting from PowerFactory – Performing calculations in PowerFactory and exporting back the results to the original application. • Integration 348

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20.2. DGS INTERFACE – Importing data sets to PowerFactory from GIS or SCADA, performing calculations, and exporting back results to GIS or SCADA.

20.2.2

DGS Structure (Database Schemas and File Formats)

PowerFactory ’s DGS interface is based on the PowerFactory data model. Data can be imported and exported with DGS using different file formats and database schemas. The following database schemas or file formats are supported: • Database Schemas – Oracle DB Server (ODBC client 10 or newer) – Microsoft SQL Server (ODBC driver 2000 or newer) – System DSN (ODBC) • File Formats – DGS File - ASCII – XML File – Microsoft Excel File (2003 or newer) – Microsoft Access File (2003 or newer) Important to note here is that the content of the files is the same; the only difference being the format. Note: It is highly recommended to use the latest available DGS version.

The core principle of DGS is to organize all data in tables. Each table has a unique name (within the DGS file or database/table space) and consists of one or more table columns, where generally all names are case-sensitive. For more detailed information on the DGS structure, please refer to the DGS Interface document located inside the PowerFactory installation folder (for example C:\Program Files\DIgSILENT\PowerFactory 15\DGS\). Also available in the same location are some examples.

20.2.3

DGS Import

To import data via the DGS interface, the general procedure is as follows: • From the main menu go to File → Import. . . → DGS Format. . . which opens the DGS-Import dialogue window. • Specify the required options in both the General and Options pages, and click on the Execute button. When importing DGS files, the user has two options: 1. Importing into a new project. With this option selected a newly generated project is left activated upon completion. 2. Importing into an existing project. If an operational scenario and/or a variation is active at the moment the import takes place, the imported data set will be divided correspondingly. For example importing breaker status (opened/closed) while an operational scenario is active will store this information in the operational scenario. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 20. POWERFACTORY INTERFACES The following sections describe each of these options. General Settings Tab Page Import into New Project By choosing this option, a project will be created where all the DGS data will be stored. The user will have the option of specifying a specific name and location (other than the default). Import into Existing Project By choosing this option, the DGS data will be imported into an already existing project. Here, the data can be selective and its not required that the imported data must be complete. In some cases, most of the objects are already existent and only an update is required for some of them. Import from The source of the data to be imported is specified with this option. If a File Format source is selected then the location and type of data (DGS, XML, MDB or XLS) must be specified. If a Database Schema source is selected, then a DB service, User and Password information is required (the SQL server option will require an extra Database information). Note: The GIS conversion uses millimetre units with respect to the bottom-left origin and A0 paper format limit (1188 x 840 mm). It could therefore be necessary to transform the GIS coordinates before creation of the “.DGS" file.

For more detailed information on the General settings, please refer to the DGS Interface document located inside the PowerFactory installation folder (for example C:\Program Files\DIgSILENT\PowerFactory 15\DGS\). Options Settings Tab Page Predefined Library A predefined library located somewhere else in the database can be selected. The option of copying the library into the project is also available. Options for DGS version :o Logic:p Logic:q los:r los:s

Value 8 ’HIGH’ ’enabled’ 18,5 19,5

Table 20.10.5: Parameter Example

Group G H1 H2 H3

Name a b c d c d c d

Type integer in [0,10] float string float in [0.03,1.65] string float in [0.03,1.65] string float in [0.03,1.65]

Default 0 -0.32 ’DEFAULT’ 1.0 ’DEFAULT’ 1.0 ’DEFAULT’ 1.0

Unit A l/s

Table 20.10.6: Multiple Setting Group Definition

In PowerFactory a device has exactly one state (or setting). Therefore when data is transferred between PowerFactory and StationWare , always a concrete device setting in StationWare must be specified. For PowerFactory purposes a special PowerFactory planning phase is introduced. The transfer directions are specified as follows: • Imports from StationWare into PowerFactory are restricted to Applied and PowerFactory settings. Applied denotes the current applied setting (Applied) or a previous applied (Historic) setting. • Exports from PowerFactory to StationWare are restricted to the PowerFactory setting. (Applied and Historic settings are read-only and can never be changed). (Actually PowerFactory ’s sophisticated variant management is similar to the phase concept, but there is no obvious way how to bring them together.)

20.10.4

Configuration

In order to transfer data between PowerFactory and StationWare both systems must be configured. StationWare Server An arbitrary StationWare user account can be used for the StationWare interface in PowerFactory. The user must have enough access rights to perform operations e.g. for the export from PowerFactory to StationWare write-rights must be granted. The bi-directional transfer of settings is restricted to lifecycle phases with

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20.10. STATIONWARE INTERFACE 1. status PLANNING or REVIEW and 2. with a cardinality constraint of 1 i.e. there may exist one or no such setting for one device. Please ensure that at least one phase fulfils these requirements, and there exists a setting of this phase. PowerFactory Client The client operating system must allow connections to the server (network and firewall settings etc.). Nothing has to be done in the PowerFactory configuration itself. The TypRelays in the Library must of course support StationWare/PowerFactory mapping.

20.10.5

Getting Started

This section is a simple walkthrough and covers the most essential StationWare interface functionality. By using a simple PowerFactory project and simple StationWare substation, it describes 1. how relays in StationWare and PowerFactory are created, 2. how these relays are linked, 3. how settings can be exported from PowerFactory to StationWare , 4. how settings can be imported again into PowerFactory . All (especially the more advanced) options and features are described in the reference section (see Section 20.10.6: Reference). Prepare substation in StationWare We begin with the StationWare side. We create a substation and two relays within: • start the web browser, • log on to the StationWare system, • create a new substation titled Getting Started, • create two relays named Getting Started Relay 1 and Getting Started Relay 2 in the Getting Started substation In the HTML interface the station detail page should look as shown in Figure 20.10.6. • Go to the detail page of the Getting Started Relay 1 (Figure 20.10.7). Since we have just created the device it has no settings, yet. Later it will contain a PowerFactory setting which reflects the relay state on the PowerFactory side.

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Figure 20.10.6: Substation

Figure 20.10.7: Device

Prepare project in PowerFactory Create a new PowerFactory project and create a simple grid within • start PowerFactory , • create a new project titled GettingStarted, • draw a simple grid with two terminals (ElmTerm) connected by a line (ElmLne) as shown in Figure 20.10.8. 376

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20.10. STATIONWARE INTERFACE

Figure 20.10.8: Grid

Now add a relay to the upper terminal • right-click the cubicle quadrangle with the mouse. A context menu pops up. • select New Devices. . . /Relay Model. . . as shown in Figure 20.10.9. A dialogue pops up that allows you to specify the settings of the new relay (ElmRelay ). • insert Getting Started Relay 1 as Name • select an appropriate Relay Type which supports StationWare import/export (see Figure 20.10.10). • press OK • in the same way add a relay Getting Started Relay 2 to the second terminal. PowerFactory ’s object filter mechanism gives an overview over all devices inside the current project.

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Figure 20.10.9: Cubicle context menu

• Press the icon (Edit Relevant Objects for calculation) in the toolbar and select the icon (ElmRelay ) to filter out all non-relay objects as shown in Figure 20.10.11. All calculation relevant relays (actually there only the two we created above) are displayed in a table (see Figure 20.10.12). Link Relays and establish a Connection Now the PowerFactory relays must get linked to the StationWare relays. • mark both relay

icons with the mouse,

• press the right mouse button. A context menu pops up as shown in Figure 20.10.13. • select the StationWare menu item, • select the Select Device ID item. A Log on to StationWare server dialogue pops up. Since this is the first time PowerFactory connects to the StationWare server some connection settings must be entered.

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20.10. STATIONWARE INTERFACE

Figure 20.10.10: Relay dialogue

Figure 20.10.11: Relay object filter

• enter the Server Endpoint URL of the StationWare server. The URL should have a format similar to http://192.168.1.53/psmsws/psmsws.asmx • enter Username and Password of a valid StationWare user account.

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Figure 20.10.12: Relay display

Figure 20.10.13: Device context menu

Figure 20.10.14 shows the dialogue settings.

Figure 20.10.14: Log on dialogue

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20.10. STATIONWARE INTERFACE The connection procedure may take some seconds. If the server could be accessed and the user could be authenticated a success message is printed into the output window DIgSI/info - Established connection to StationWare server ’http://192.168.1.53/psmsws/psmsws.asmx’as user’pf00002’ Otherwise an error dialogue pops up. Correct the connection settings until the connection is successfully created. The reference section (Section 20.10.6) explains the connection options in detail. Having established a connection to the server, a browser dialogue pops up which displays the location hierarchy as known from the StationWare HTML interface. The dialogue is shown in Figure 20.10.15. • navigate to the Getting Started substation, • select the Getting Started Relay 1 device, • press OK.

Figure 20.10.15: Browser dialogue

Now the PowerFactory relay is “connected" to the StationWare device. • in the same way select Getting Started Relay 2 for the second PowerFactory relay. Export and Import Settings Having linked PowerFactory to StationWare devices, the transfer between both systems can be started. • mark the relays with the mouse and right-click to get the relay context menu as shown in Figure 20.10.13. • select the Export. . . item in the StationWare menu entry A ComStationware dialogue is shown which allows to specify the export options (See Figure 20.10.16. See Export and Import Settings in the Section 20.10.6 Reference section for all export options.

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Figure 20.10.16: ComStationware dialogue

• select PowerFactory as Life cycle Phase, • press Execute. After a few seconds the relay settings are transferred to the server, and the output window contains the message DIgSI/info - Exported 2 of 2 device settings successfully The result can now be observed in the StationWare HTML interface.

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Figure 20.10.17: Device detail page • navigate to the relay detail view of the Getting Started Relay 1 relay (c.f. Fig. 20.10.17) Observe the new created PF setting. The phase of this setting is PowerFactory. • switch to the settings detail page of the new PF setting (c.f.Fig. 20.10.18).

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CHAPTER 20. POWERFACTORY INTERFACES The setting values should correspond to the relay state in PowerFactory. In the same way the Getting Started Relay 2 relay has a new PF setting. Now try the opposite direction and import a setting from StationWare into PowerFactory. • modify the PF settings in StationWare by entering some other values • in PowerFactory mark the relays with the mouse and right-click to get the relay context menu as shown in Figure 20.10.13. • select the Import. . . item in the StationWare menu entry. Again the ComStationware dialogue (see Figure 20.10.16) pops up as known from the export. • leave the default settings, • press Execute. Again the result of the settings transfer is reflected in the output window: DIgSI/info - Imported 2 of 2 device settings successfully • find ElmRelay object parameters changed according to the changes on the StationWare side All import options are described in detail in the reference section : Export and Import Settings.

20.10.6

Reference

This section describes all options and features concerning the StationWare interface. The Device Context Menu Almost all functionality can be accessed by the device context menu. Mark one ore more objects which supports the StationWare transfer e.g. ElmRelay • in the object filter (Figure 20.10.13) • in the data manager as shown in Figure 20.10.19.

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Figure 20.10.19: Device context menu

The StationWare submenu contains the entries as follows: Import. . . opens the ComStationware dialogue and sets the device selection according to the above selected device objects. The ComStationware dialogue settings are explained in detail in section 20.10.6 : The ComStationware Object. Export. . . does the same for the export direction. Select Device ID. . . starts the Browser dialogue (Figure 20.10.23) to link this device to a StationWare device. The dialogue is subject of section 20.10.6 : The Browser Dialogue. Reset Device ID resets the device ID. Connect. . . terminates the current StationWare session if itŠs already existing. Shows a Log On dialogue. The connection settings are covered by Section 20.10.6. This may be useful when you are using several StationWare accounts and want to switch between them. Disconnect terminates the StationWare session Connection Similar to the HTML interface the StationWare interface in PowerFactory is session - oriented: when a user logs on to the system by specifying a valid StationWare account (username and password) a new session is created. Only inside such a session StationWare can be used. The account privileges restrict the application functionality e.g. an administrator account is more powerful than a usual user account.

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Figure 20.10.20: Log on dialogue

Working with PowerFactory the first time the StationWare server is required the Logon dialogue is shown as shown in Figure 20.10.20. The StationWare connection options are stored in the user settings (Figure 20.10.21). After each successful logon the user settings are updated.

Figure 20.10.21: Log on dialogue

As mentioned in the Architecture section (Section 20.10.2) StationWare is a client-server application. The StationWare server component is located on a server machine in the internet. The client component is the PowerFactory application which is running on a client machine. The technology PowerFactory and StationWare use to communicate is called web services and is standardized like many other internet technologies (HTML, HTTP). The server computer (or more exactly the StationWare service application on the server computer) has a ’name’ by which it can be accessed. This ’name’ is called service endpoint and resembles a web page URL: http://the.server.name/psmsws/psmsws.asmx or http://192.168.1.53/psmsws/psmsws.asmx http denotes the protocol, the.server.name is the computer name (or DNS) of the server computer and psmsws/psmsws.asmx is the name of the StationWare application. The connection options are as follows: Service Endpoint The Service Endpoint denotes the StationWare server ’name’ as described above Username/Password Username and Password have to be valid user account in StationWare . A 386

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20.10. STATIONWARE INTERFACE StationWare user account has nothing to do with the PowerFactory user account. The very same StationWare account can be used by two different PowerFactory users. The privileges of the StationWare account actually restrict the functionality. For device import the user requires readaccess rights. For exporting additionally write-access rights are required. The Browser Dialogue As mentioned in the Concept description (see Section 20.10.3: Device) the StationWare device ID is stored as Foreign Key in the ElmRelay object dialogue (Description page) as shown in Figure 20.10.22.

Figure 20.10.22: ElmRelay dialogue

A more convenient way is to use the Browser dialogue shown in Figure 20.10.23. The dialogue allows to browse through the StationWare location hierarchy and select a device. The hierarchy data is cached to minimize network accesses. Due this caching it’s possible that there may exist newly created locations or devices which are not displayed in the browser dialogue. The Refresh button empties the cache and enforces PowerFactory to re-fetch the correct data from the server. The ComStationware Object In PowerFactory almost everything is an object: relays are ElmRelay objects, users are IntUser objects, and grids are ElmNet objects. What may be on the first sight confusing is the fact that actions are objects as well: for a short-circuit calculation a ComShc object is created. The calculation can be performed with several options e.g. 3-Phase, single phase, or 3 Phase to Neutral.

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CHAPTER 20. POWERFACTORY INTERFACES You can even specify the fault location. All these calculation options are stored in the ComShc object. Every action object has an Execute button which starts the action. In fact there is a large number of parametrized actions like load flow calculation (ComLdf ), simulation (ComSim), there is even a ComExit object that shuts down PowerFactory. All objects which can ’do’ something have the Com prefix. Since the StationWare interface is actually ’doing’ something (it does import data, it does export data) it is implemented as a ComStationware object. The ComStationware object is used both for the import (Section 20.10.6) and the export (Section 20.10.6). It is located in the projectŠs study case according to PowerFactory conventions. By default the study case of a new project contains no ComStationWare object. It is automatically created when it is first needed, as well as the ComShc object is instantiated at the time when the first short-circuit calculation is performed. Import Options The ComStationware dialogue provides import options as follows (Figure 20.10.24): Transfer Mode select Import from StationWare as Transfer Mode Check only Plausibility if the Check only Plausibility flag is enabled the import is only simulated but not really executed. Life cycle Phase/Time stam A list of available life cycle phases is shown.

Figure 20.10.24: ComStationware import options • PowerFactory selects the current setting with PowerFactory phase as source setting. 388

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20.10. STATIONWARE INTERFACE • if Applied is selected the current Applied setting is transferred. If additionally a Timestamp value is entered the setting that was applied at this time is transferred which may either be Applied or Historic. The Timestamp format is in ISO format: e.g. 2005-02-28 22:27:16 The time part may be omitted. Then 00:00:00 AM is assumed. All Devices If All Devices is enabled, all calculation-relevant devices are imported. Devices not supported by StationWare are ignored. Device Selection Unless All Devices is enabled, the Device Selection provides a more subtle way to specify which devices are to be transferred. The Device Selection parameter can be • an ElmRelay object: this and only this relay is imported • a SetSelect object: a SetSelect is a container that may hold several objects. All of them are transferred, except the ones not supported by StationWare • a SetFilt object: the SetFilt is the most flexible way to specify the device selection e.g. you can select all devices in the project of type ElmRelay and whose name begin with PW. . . . Devices outside the activated project are ignored. The Device Selection is automatically set if the Device Context Menu mechanism (Section 20.10.6 : The Device Context Menu) is used. All Settings Groups/Group Index This parameter specifies how multiple settings groups (MSG) are handled. • If the relay in StationWare has MSGs and the PowerFactory relay model supports MSGs and – All Settings Groups is enabled: then all groups are transferred – All Settings Groups is disabled: then only the Group Index -th group is transferred. • If the relay in StationWare has MSGs and the PowerFactory relay model doesn’t support MSGs: then the Group Index-th group is imported. These parameters are ignored completely if the relay has no MSGs. The import transfer is started by pressing Execute.

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Figure 20.10.25: ComStationware export options

Export Options The export options are almost identical to the import options (Figure 20.10.25): Transfer Mode Select Export as Transfer Mode Life cycle Phase A list of possible life cycle targets is shown. Please have in mind that a setting of the life cycle is available. Applied settings can never be changed. Click Execute to start the data transfer. Then the PowerFactory -relevant parameters are copied upon the existing target setting.

20.10.7

Technical Reference

The purpose of this section is to describe what happens internally inside PowerFactory when device settings are exported or imported. This section also explains how new device types are integrated. PowerFactory is delivered with a library of relay models. This library cannot contain all relays of all manufacturers. A way how to enhance the 390

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20.10. STATIONWARE INTERFACE library for new device types is shown in this section as well. The StationWare interface is heavily based on DPL (DIgSILENT Programming Language) which is documented in a separate DPL Manual. Overview For each device type (TypRelay ) and each transfer direction a separate DPL script is required. The import DPL script takes the StationWare attributes and a ElmRelay object as input and fills somehow the ElmRelay objects and its sub-objects parameters. The export DPL script takes a ElmRelay object as input parameter and calculates some output parameters which are the StationWare attributes. Note: DPL’s most important benefit is: you can do anything. That’s exactly DPL’s most important disadvantage as well. Be sure that your DPL scripts do what they should do and not more. An import script should only set the parameters in the ElmRelay object and its subcomponents. An export script shouldn’t change anything at all (at least within PowerFactory ).

The scripts have to be named PsmsImport.ComDpl and PsmsExport.ComDpl and must be located in the same folder as the TypRelay object. Type data like TypRelay objects should be located in a library folder e.g. in the project library. If it is referenced from several projects, it belongs into a global library. See Figure 20.10.26 for an example database structure. Import Scripts The algorithm used for the import from StationWare to PowerFactory is as follows. Let d be the device whose setting is to be imported: 1. let t be d’s device type 2. let dpl be the PsmsImport.ComDpl object near t 3. initialize dpl’s input parameter with the device attributes from StationWare 4. initialize dplŠs external object parameter Relay with d 5. execute dpl

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Figure 20.10.26: Database structure

The execution step actually sets the relay parameters. We use the StationWare device type example shown in table 20.10.1 from the Concept section (Section 20.10.3) and the PowerFactory device type as shown in table 20.10.3 The StationWare attributes are G.a, G.b, G.c, H.d, and H.e, the PowerFactory parameters are I>:o, Logic:p, Logic:q, Ios:r, and Ios:s. Only the attributes G.a, G.c, and H.d and the parameters I>:o, Logic:p, and Ios:r are mapped. The others are ignored since there is no equivalent concept on the other system. The PsmsImport.ComDpl must meet the requirements as follows: Name must be PsmsImport General Selection must be empty Input Parameters this table holds the StationWare attributes. The Name has the format [group name]__[attribute name] The Type may either be int (for integer numbers), double (for floating point numbers), or string (for string and enum values). The Value field must be empty. The attribute unit has to inserted in the Unit field if appropriate. A Description may be inserted, too. External Object this table contains exactly one entry: an object with the Name Relay. The object column must be empty. The Input parameters get initialized with the StationWare attribute values and the External Object with the current relay. The second page of the ComDpl script holds the output parameters. They have the meaning as follows. Remote Script this parameter must be un-set

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20.10. STATIONWARE INTERFACE General Selection the table must have one entry with Name Result of Type String. The DPL script should set this parameter to OK if the import procedure was successful. Otherwise it may hold an error message which is displayed in the output window. The code must be a valid DPL program. It should set the relay parameters according to the input parameters. Export Scripts The export direction is almost symmetric to the import process. Be d the device whose setting is to exported: 1. let t be dŠs device type 2. let dpl be the PsmsExport.ComDpl object near t 3. initialize dpl’s external object parameter Relay with d 4. execute dpl 5. transfer dpl’s output parameter to the setting in StationWare The export DPL script must also meet some requirements: Name ComDpl.Name must be PsmsExport. General Selection must be empty Input Parameters this table must be empty External Object this table contains exactly one entry: an object with the Name Relay. The object column must be empty. The second page of the ComDpl script holds the output parameters. They have the meaning as follows. Remote Script this parameter must be un-set Result Parameters the table must have the first entry with Name Result of Type String. The DPL script should set this parameter to OK if the import procedure was successful. Otherwise it may hold an error message which is displayed in the output window. Below the Result parameter are the StationWare attributes. The code must be a valid DPL program. It should not change the database. How to create a new Device Type conversion This section gives some practical guidelines how to create the conversion scripts for new types. First create a test environment: • create in StationWare a new substation with one device of the desired device type. Create a default PowerFactory setting for this device. • create a simple PowerFactory project which contains a device of the desired type • link the PowerFactory device to the StationWare device by setting the foreign key to the device ID. Then write the import script: • create an empty PsmsImport.ComDpl near the TypRelay object. • define the input and output parameters of the ComDpl object DIgSILENT PowerFactory 15, User Manual

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CHAPTER 20. POWERFACTORY INTERFACES • write the DPL code • test the script by importing the PowerFactory setting Iterate these steps until there are no error messages. Change the setting in StationWare and re-try the import. In quite the same way create and verify a PsmsExport.ComDpl script.

20.11

API (Application Programming Interface)

For a further detailed description on API, a reference document is available inside the subfolder api in the installation directory of the software (i.e. C:\Program Files\DIgSILENT\PowerFactory 15\api).

20.12

Python

20.12.1

Introduction

This Section describes the integration of the Python scripting language in PowerFactory and explains the associated procedure for developing Python scripts. The Python scripting language can be used in PowerFactory to perform the following actions: • Automate tasks • Create user defined calculation commands • Integrate PowerFactory into other applications Some of the most notable features of Python are mentioned below: • General-purpose, high-level programming language • Very clear, readable syntax • Non-proprietary, under liberal open source license • Widely used • Extensive standard libraries and third party modules – Interfaces to external databases and Microsoft Office like applications – Web-services, etc. Python integration makes all of the above advantages available in PowerFactory . Several steps need to be followed to start using Python with PowerFactory : 1. Install a Python Interpreter 2. Write Python scripts using the PowerFactory Python module ’powerfactory.pyd’ 3. Execute a Python script within PowerFactory with the Python command object (ComPython)

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20.12.2

Installation of a Python Interpreter

By default, no Python Interpreter is installed with PowerFactory . A separate installation of the Python Interpreter is therefore necessary. The recommended version is available in the PowerFactory installation directory (e.g. C:\Program Files\DIgSILENT\PowerFactory 15.1\python). PowerFactory supports the CPython 3.3 implementation of the Python programming language. The PowerFactory architecture (32 or 64 bit) determines the Python architecture as shown below: • PowerFactory 32 bit requires Python Interpreter for 32 bit • PowerFactory 64 bit requires Python Interpreter for 64 bit To check which PowerFactory architecture is installed, press Alt-H to open the Help menu and choose the About PowerFactory. . . command. If the name of PowerFactory includes “(x86)" then a 32 bit version is installed. If the name of PowerFactory includes “(x64)" then a 64 bit version is installed. To avoid issues with third party software, the Python Interpreter should be installed with default settings (for all users, into the directory proposed by the installer). Depending on the functions to be performed by a particular Python script, it may be necessary to install the corresponding Python add-on/package. As an example, Microsoft Excel can be used by a python script if the “Python for Windows Extensions" PyWin32 (http://sourceforge.net/projects/pywin32/) package is installed, which includes Win32 API, COM support and Pythonwin extensions.

20.12.3

The Python PowerFactory Module

The functionality of PowerFactory is provided in Python through a dynamic Python module (“powerfactory.pyd") which interfaces with the PowerFactory API (Application Programming Interface). This solution enables a Python script to have access to a comprehensive range of data available in PowerFactory : • All objects • All attributes (element data, type data, results) • All commands (load flow calculation, etc.) • Most special built-in functions (DPL functions) A Python script which imports this dynamic module can be executed from within PowerFactory through the new command ComPython (see Section 20.12.4) or externally (PowerFactory is started by the Python module in engine mode)(see Section 20.12.5).

20.12.3.1

Python PowerFactory Module Usage

To allow access to the Python PowerFactory Module it must be imported using the following Python command: import powerfactory

To gain access to the PowerFactory environment the command below must be added: app = powerfactory.GetApplication()

A python object of class powerfactory.Application is called an application object. Using the application object from the command above(“app"), it is possible to access global PowerFactory functionality. Several examples are shown below: DIgSILENT PowerFactory 15, User Manual

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CHAPTER 20. POWERFACTORY INTERFACES user = app.GetCurrentUser() project = app.GetActiveProject() script = app.GetCurrentScript() objects = app.GetCalcRelevantObjects() lines = app.GetCalcRelevantObjects("*.ElmLne") sel = app.GetDiagramSelection() sel = app.GetBrowserSelection() project = app.CreateProject("MyProject", "MyGrid") ldf = app.GetFromStudyCase("ComLdf")

The listed methods return a data object (Python object of class powerfactory.DataObject) or a python list of data objects. It is possible to access all parameters and methods associated with a data object. Unlike DPL scripting, with python scripting it is necessary to use the dot (.) operator instead of the colon (:) operator in order to access individual parameters of objects (in DPL the syntax is: objectname:parametername). Examples: project = app.GetActiveProject() projectName = project.loc_name project.Deactivate()

or: lines = app.GetCalcRelevantObjects("*.ElmLne") line = lines[0] currLoading = line.c.loading

For printing into the PowerFactory output window the following application object (e.g. “app" object) methods are provided: app.PrintPlain("Hello world!") app.PrintInfo("An info!") app.PrintWarn("A warning!") app.PrintError("An error!")

Printing the string representation of data objects into the PowerFactory output window makes them clickable (creates a hyperlinked string in the output window): project = app.GetActiveProject() app.PrintPlain("Active Project: " + str(project))

A list of all parameters and methods associated with an object can be given using the dir() function as shown below: project = app.GetActiveProject() app.PrintPlain(dir(project))

20.12.3.2

Python PowerFactory Module Reference

A detailed Python Module Reference document is available containing a comprehensive list of supported functions.

20.12.4

The Python Command Object (ComPython)

The Python command object ComPython links to a Python script file as shown in Figure 20.12.1. It stores only the file path of the script and not the file itself. For optimal operation, the script should be located in the External Data directory. 396

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Figure 20.12.1: Python command object ComPython dialogue

The script may be executed by clicking on the Execute button of the corresponding dialogue. Editing the script file is possible by clicking the Open in External Editor button. The preferred editor may be chosen in the External Applications tab of the PowerFactoryConfiguration dialogue by selecting the Tools → Configuration. . . menu item from the main menu as shown in Figure 20.12.2). Python scripts may be created in any text editor as long as the script file is saved using the UTF-8 character encoding format.

Figure 20.12.2: Selection of the preferred Python editor program

The Python command object may also contain objects or references to other objects available in the PowerFactory database. These can be accessed by clicking on the Contents button. New objects are defined by first clicking the New Object icon in the toolbar of the Python script contents dialogue and then by selecting the required object from the New Object pop-up window which appears. References to other objects are created by defining a “IntRef" reference object. An example showing the possible contents of a Python command object is shown in Figure 20.12.3).

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Figure 20.12.3: Contents of a Python command object

20.12.4.1

Creating a New Python Command

To create a new Python command object click on the New Object ( ) icon in the toolbar of the data manager and select DPL Command and more as shown in Figure 20.12.4). From the drop-down list of the ’Element’ field select the ’Python Script (ComPython)’ element. Then press OK and a new Python command is created. The Python command dialogue is now shown (as in Figure 20.12.1) and the file path to the script can now be specified. This dialogue is also opened by double-clicking a Python script, by selecting Edit from the context sensitive menu or by selecting the script from the list when pressing the main toolbar icon Execute Scripts ( ).

Figure 20.12.4: Creating a new Python command object (ComPython)

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20.12. PYTHON 20.12.4.2

Executing a Python Command

To execute a Python command double click the Python command object. After the dialogue of the script appears, click the Execute button. Alternative methods for Python script execution are listed below: • From the Data Manager Window – Right click on the Python command object and from the context sensitive menu select the command Execute Script – Right click in a blank area and from the context sensitive menu select the command Execute Script. A list of existing DPL and Python scripts contained in the global and local library will pop up. Select the required Python script and click OK. • From the single line diagram – Select one or more elements in the single line diagram. Right click the marked elements and from the context sensitive menu select the command Execute Script. A list of existing DPL and Python scripts contained in the global and local library will pop up. Select the required Python script and click OK. – A button may be created in the single line diagram to automate the execution of a specific Python script. • From the main toolbar - Click the icon Execute Scripts . A list of existing DPL and Python scripts from the global and local library will appear. Select the specific Python script and click OK.

20.12.5

Running PowerFactory in Engine Mode

PowerFactory may be run externally by Python. In order to do this, the script must additionally import the file path to the dynamic module (“powerfactory.pyd"). The following commands should be included to obtain access to the PowerFactory environment in engine mode: # Add powerfactory.pyd path to python path. # This is an example for 32 bit PowerFactory architecture. import sys sys.path.append("C:\\Program Files\\DIgSILENT\\PowerFactory 15.1\\python") #import PowerFactory module import powerfactory #start PowerFactory in engine mode app = powerfactory.GetApplication() #run Python code below #.....................

The PowerFactory environment can be accessed directly from the Python shell as shown in Figure 20.12.5

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Figure 20.12.5: Python Shell

20.12.6

Debugging Python Scripts

As with any other Python script, it is possible to remotely debug scripts written for PowerFactory by using specialised applications.

20.12.6.1

Prerequisites

The recommended IDE for debugging is Eclipse (www.eclipse.org) with the Python add-on PyDev (www.pydev.org). 1. Install Eclipse Standard from www.eclipse.org/downloads/ 2. Open Eclipse 3. Click “Install New Software . . . " in the “Help" menu 4. Add the repository http://pydev.org/updates and install PyDev

20.12.6.2

Debugging a Python script for PowerFactory

The following is a short description of remote debugging with PyDev. For more information please consult the remote debugger manual of PyDev (http://pydev.org/manual_adv_remote_debugger. html). 1. Start Eclipse 2. Open Debug perspective 3. Start the remote debugger server by clicking “Start Debug Server" in the “Pydev" menu 4. Start PowerFactory 5. Prepare the python script for debugging: • Add “pydevd.py" path to sys.path • Import PyDev debugger module “pydevd" • Start debugging calling pydevd.settrace() Example:

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20.12. PYTHON #prepare debug import sys sys.path.append \ ("C:\\Program Files\\eclipse\\plugins\\org.python.pydev_2.8.2.2013090511\\pysrc") import pydevd #start debug pydevd.settrace()

6. Execute the Python command object of the script 7. Change to Eclipse and wait for the remote debugger server It is not possible to stop and restart the remote debugger server while running PowerFactory .

20.12.7

Example of a Python Script

A small practical example which calculates a load-flow and prints a selection of results to the output window. The following script can be executed from within PowerFactory . if __name__ == ’__main__’: #connect to PowerFactory import powerfactory as pf app = pf.GetApplication() if app is None: raise Exception("getting PowerFactory application failed") #print to PowerFactory output window app.PrintInfo("Python Script started..") #get active project prj = app.GetActiveProject() if prj is None: raise Exception("No project activated. Python Script stopped.") #retrieve load-flow object ldf = app.GetFromStudyCase("ComLdf") #force balanced load flow ldf.iopt_net = 0 #execute load flow ldf.Execute() #collect all relevant terminals app.PrintInfo("Collecting all calculation relevant terminals..") terminals = app.GetCalcRelevantObjects("*.ElmTerm") if not terminals: raise Exception("No calculation relevant terminals found") app.PrintPlain("Number of terminals found: %d" % len(terminals)) for terminal in terminals: voltage = terminal.__getattr__("m.u") app.PrintPlain("Voltage at terminal %s is %f p.u." % (terminal , voltage)) #print to PowerFactory output window app.PrintInfo("Python Script ended.")

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Part IV

Power System Analysis Functions

Chapter 21

Load Flow Analysis 21.1

Introduction

Whenever evaluating the operation and control of power systems, the electrical engineer is typically encountered with questions such as: • Are the voltages of every busbar in the power system acceptable? • What is the loading of the different equipment in the power system? (transformers, transmission lines, generators, etc.) • How can I achieve the best operation of the power system? • Does the power system have a weakness (or weaknesses)? If so, where are they located and how can I countermeasure them? Although we may consider that the above questioning would arise only when analyzing the behaviour of “existing" power systems; the same interrogations can be formulated when the task relates to the analysis of “future" systems or “expansion stages" of an already existing power system; such as evaluating the impact of commissioning a transmission line or a power plant, or the impact of refurbishment or decommissioning of equipment (for example shutting down a power plant because it has reached its life expectancy).

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Figure 21.1.1: Power System Analysis: System Operation and System Planning

Taking into account these two aspects: 1) Present operation and 2) Future operation, is how power should be analyzed. From one side, an operation or control engineer requires relevant information to be available to him almost immediately, meaning he must be able to obtain somehow the behaviour of the power system under different configurations that can occur (for example by opening or closing breakers in a substation); on the other side, a planning engineer requires obtaining the behaviour of the system reflecting reinforcements that have not yet been built while considering the corresponding yearly and/or monthly load increase. Regardless of the perspective, the engineer must be able to determine beforehand the behaviour of the power system in order to establish, for example, the most suitable operation configuration or to detect possible weakness and suggest solutions and alternatives. Figures 21.1.2 and 21.1.3 illustrate the system operation and planning aspects.

Figure 21.1.2: Power System Operation Example

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21.1. INTRODUCTION

Figure 21.1.3: Power System Planning Example

Load flow calculations are used to analyze power systems under steady-state non-faulted (short-circuitfree) conditions. Where steady-state is defined as a condition in which all the variables and parameters are assumed to be constant during the period of observation. We can think of this as ”taking a picture” of the power system at a given point in time. To achieve a better understanding let us refer to Figure 21.1.4. Here a 24 hour load demand profile is depicted. The user can imagine this varying demand to be the demand of a specific area or region, or the demand of a whole network. In this particular case the load is seen as increasing from early in the morning until it reaches itŠs maximum at around 18:00 hrs. After this point in time, the total load then begins to decrease. A load flow calculation is stated to be a steadystate analysis because it reflects the system conditions for a certain point in time, such as for instance at 18:00 hrs (maximum demand). As an example, if we require determining the behaviour of the system for every hour of the day, then 24 load flows need to be performed; if the behaviour for every second is required then the number of load flow calculations needed would amount to 86 400. In PowerFactory , the active power (and/or reactive power) of the loads can be set with a Characteristic so they follow a certain profile (daily, weekly, monthly, etc.). By doing so, the active power will change automatically according to the date ant time specified. For more information please refer to Chapter 16(Parameter Characteristics, Load States, and Tariffs).

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Figure 21.1.4: Example of a Load Demand Curve

A load flow calculation will determine the active and reactive power flows for all branches, and the voltage magnitude and phase for all nodes. The main areas for the application of load flow calculations can be divided in normal and abnormal (Contingency) system conditions as follows: Normal System Conditions • Calculation of branch loadings, system losses and voltage profiles. • Optimization tasks, such as minimizing system losses, minimizing generation costs, open tie optimization in distributed networks, etc. • Calculation of steady-state initial conditions for stability simulations or short-circuit calculations using the complete superposition method. Abnormal System Conditions • Calculation of branch loadings, system losses and voltage profiles. • Contingency analysis, network security assessment. • Optimization tasks, such as minimizing system losses, minimizing generation costs, open tie optimization in distributed networks, etc. • Verification of system conditions during reliability calculations. • Automatic determination of optimal system resupplying strategies. • Optimization of load-shedding. • Calculation of steady-state initial conditions for stability simulations or short-circuit calculations using the complete superposition method (special cases). Regarding the above definitions of ”normal” and ”abnormal” system conditions, a distinction should be made in terms of the manner simulations should be performed:

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21.2. TECHNICAL BACKGROUND Simulation of normal operating conditions: Here, the generators dispatch as well as the loads are known, and it is therefore sufficient for the load flow calculation to represent these generators dispatch and to provide the active and reactive power of all loads. The results of the load flow calculation should represent a system condition in which none of the branch or generator limits are exceeded. Simulation of abnormal operating conditions: Here a higher degree of accuracy from the models is needed. It can no longer be assumed that the entire system is operating within limits. The models must be able to correctly simulate conditions which deviate from the normal operating point. Hence the reactive power limits of generators or the voltage dependency of loads must be modelled. Additionally, in many applications, the active power balance cannot be established with a single slack bus (or machine). Instead, a more realistic representation of the active and reactive power control mechanisms have to be considered to determine the correct sharing of the active and reactive power generation. Besides the considerations regarding abnormal conditions presented above, the assumption of balanced systems may be inappropriate for certain distribution networks. State of the art computational tools for power systems analysis must be therefore able to represent unbalanced networks for load flow calculations as well. The calculation methods and the options provided by PowerFactory Šs load flow analysis function allow the accurate representation of any combination of meshed 1-, 2-, and 3-phase AC and/or DC systems. The load flow tool accurately represents unbalanced loads, generation, grids with variable neutral potentials, HVDC systems, DC loads, adjustable speed drives, SVSs, and FACTS devices, etc., for all AC and DC voltage levels. With a more realistic representation of the active and reactive power balance mechanisms, the traditional requirement of a slack generator is left optional to the user. The most considerable effect of the resistance of transmission lines and cables is the generation of losses. The conductor resistance will at the same time depend on the conductor operating temperature, which is practically linear over the normal range of operation. In order to carry out such type of analysis, PowerFactory offers a Temperature Dependency option, so that the conductor resistance is corrected according to the specified temperature value. For very fast and reliable analysis of complex transmission networks, where only the flow of active power through the branches is considered, PowerFactory offers an additional load flow method, namely “DC load flow (linear)", which determines the active power flows and the voltage angles within the network. The following sections introduce the calculation methods and the options provided with PowerFactory ’s load flow tool. This information is a guide to the configuration of the PowerFactory load flow analysis command

21.2

Technical Background

This section presents the general aspects of the implementation of PowerFactory ’s load flow calculation tool. An understanding of the concepts introduced here should be sufficient background to manage the options presented in the load flow analysis command dialogue. Further technical details related to the models (Network Components) implemented in PowerFactory for load flow calculations are provided in the Appendix C: Technical References of Models.

21.2.1

Network Representation and Calculation Methods

A load flow calculation determines the voltage magnitude (V) and the voltage angle (𝜗) of the nodes, as well as the active (P) and reactive (Q) power flow on branches. Usually, the network nodes are represented by specifying two of these four quantities. Depending on the quantities specified, nodes can be classified as: DIgSILENT PowerFactory 15, User Manual

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CHAPTER 21. LOAD FLOW ANALYSIS • PV nodes: here the active power and voltage magnitude are specified. This type of node is used to represent generators and synchronous condensers whose active power and voltage magnitude are controlled (synchronous condensers P=0). In order to consider equipment limits under abnormal conditions (as mentioned in the previous section), reactive power limits for the corresponding network components are also used as input information. • PQ nodes: here the active and reactive power are specified. This type of node is used to represent loads and machines with fixed values. Loads can also be set to change (from their original Po and Qo values at nominal voltage) as a function of the voltage of the node to which the load itself is connected. Elements specified as PQ (for example synchronous machines, static generator’s PWM converters or SVS’s) can be ”forced” by the algorithm so that the P and Q resulting from the load flow are always within limits. • Slack node: here the voltage magnitude and angle are fixed. In traditional load flow calculations the slack node (associated with a synchronous generator or an external network) carries out the balancing of power in the system. • Device nodes: special nodes used to represent devices such as HVDC converters, SVSs, etc., with specific control conditions (for example the control of active power flow at a certain MW threshold in a HVDC converter, or the control of the voltage of a busbar by an SVS). Note: In traditional load flow calculations, asynchronous machines are represented by PQ nodes, assuming that the machine operates at a certain power factor, independent of the busbar voltage. Besides this traditional representation, PowerFactory offers a more accurate “slip iteration" (AS) representation based on the model equivalent circuit diagrams. For further information please refer to the corresponding Technical Reference in the Appendix C.

In contrast to other power system calculation programs, PowerFactory does not directly define the node characteristic of each busbar. Instead, more realistic control conditions for the network elements connected to these nodes are defined (see the Load Flow page of each elementŠs dialogue). For example, synchronous machines are modelled by defining one of the following control characteristics: • Controlled power factor (cos(𝜗)), constant active and reactive power (PQ); • Constant voltage, constant active power (PV) on the connected bus; • Secondary (frequency) controller (slack, SL). It is also important to note that in PowerFactory the active and reactive power balance of the analyzed networks is not only possible through a slack generator (or external network). The load flow calculation tool allows the definition of more realistic mechanisms to control both active and reactive power. For further information please refer to Section 21.2.2. AC Load Flow Method In PowerFactory the nodal equations used to represent the analyzed networks are implemented using two different formulations: • Newton-Raphson (Current Equations). • Newton-Raphson (Power Equations, classical). In both formulations, the resulting non-linear equation systems must be solved by an iterative method. PowerFactory uses the Newton-Raphson method as its non-linear equation solver. The selection of the method used to formulate the nodal equations is user-defined, and should be selected based on the type of network to be calculated. For large transmission systems, especially when heavily loaded, the standard Newton-Raphson algorithm using the “Power Equations" formulation usually converges 410

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21.2. TECHNICAL BACKGROUND best. Distribution systems, especially unbalanced distribution systems, usually converge better using the “Current Equations" formulation. In addition to the Newton-Raphson iterations, which solve the network nodal equations, PowerFactory applies an outer loop when the control characteristic of automatic transformer tap changers and/or switchable shunts is considered. Once the Newton-Raphson iterations converge to a solution within the defined tolerance (without considering the setpoint values of load flow quantities defined in the control characteristic of the tap changers/switchable shunts (see Figure 21.2.1)), the outer loop is applied in order to reach these target values. The actions taken by the outer iterative loop are: • Increasing/decreasing discrete taps; • Increasing/decreasing switchable shunts; and • Limiting/releasing synchronous machines to/from max/min reactive power limits. Once the above-listed actions are taken, a new Newton-Raphson load flow iteration takes place in order to determine the new network operating point.

Figure 21.2.1: Setting of the Control Mode for an Automatic Tap Changer

In the classical load flow calculation approach, the unbalance between phases are neglected. For the analysis of transmission networks this assumption is generally admissible. In distribution networks this assumption may be inappropriate depending on the characteristics of the network. PowerFactory allows for the calculation of both balanced (AC Load Flow, balanced positive sequence) and unbalanced (AC Load Flow Unbalanced, 3-phase (ABC)) load flows according to the descriptions above. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 21. LOAD FLOW ANALYSIS DC Load Flow Method In addition to the “AC" load flow calculations presented in this section, PowerFactory offers a so-called “DC" load flow calculation method. The DC load flow should not be interpreted as a method to be used in case of DC systems given that it basically applies to AC systems. Some occasions we may require performing fast analysis in complex transmission networks where only a reasonable approximation of the active power flow of the system is needed. For such situations the DC load flow can be used. Other applications of the DC load flow method include situations where the AC load flow has trouble converging (see Section 21.5: Troubleshooting Load Flow Calculation Problems). In this particular method, the non-linear system resulting from the nodal equations is simplified due to the dominant relation that exists between voltage angle and active power flow in high voltage networks. By doing so a set of linear equations is thereby obtained, where the voltage angles of the buses are directly related to the active power flow through the reactance of the individual components. The DC load flow does not require an iterative process and the calculation speed is therefore considerably increased. Only active power flow without losses is considered. Summarizing, the DC load flow method has the following characteristics: • The calculation requires the solving of a set of linear equations. • No iterations required, therefore fast, and also no convergence problems. • Approximate solution: – All node voltage magnitudes fixed at 1.0 per unit. – Only active power and voltage angles calculated. – Losses are neglected.

21.2.2

Active and Reactive Power Control

Active Power Control Besides the traditional approach of using a slack generator to establish the power balance within the system, PowerFactory ’s load flow calculation tool provides other active power balancing mechanisms which more closely represent the reality of transmission networks (see selection in the Active Power Control page of the load flow command). These mechanisms are implemented in the steady-state according to the control processes that follow the loss of large power stations: • As Dispatched: As mentioned at the beginning of this section, the conventional approach in load flow calculations consists assigning a slack generator, which will establish the power balance within the system. Besides this traditional approach, PowerFactory offers the option of balancing by means of a single or a group of loads (Distributed Slack by Loads). Under such assumptions, the active power of the selected group of loads will be modified so that the power balance is once again met; while leaving the scheduled active power of each generator unchanged. Other methods of balancing include considering the participation of all synchronous generators according to their scheduled active power (Distributed Slack by Generation). • According to Secondary Control: If an unbalance occurs between the scheduled active power values of each generation unit and the loads plus losses, primary control will adapt (increase/decrease) the active power production of each unit, leading to an over- or under-frequency situation. The secondary frequency control will then bring the frequency back to its nominal value, re-establishing cost-efficient generation delivered by each unit. Secondary control is represented in PowerFactory ’s load flow calculations by network components called Power Frequency Controllers (ElmSecctrl). If the Active Power Control option According to Secondary Control is selected, the generators considered by the Power Frequency Controllers establish the active power balance according to their assigned participation factors (for further information, please refer to the corresponding Technical Reference in the Appendix C). 412

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21.2. TECHNICAL BACKGROUND • According to Primary Control: Shortly following a disturbance, the governors of the units participating in primary control will increase/decrease their turbine power and drive the frequency close to its nominal value. The change in the generator power is proportional to the frequency deviation and is divided among participating units according to the gain (𝐾𝑝𝑓 ) of their primary controllers and which is depicted in Figure 21.2.2. If the Active Power Control option According to Primary Control is selected in PowerFactory ’s load flow command, the power balance is established by all generators (synchronous generators, static generators and external grids) having a primary controller gain value different than zero (parameter Prim. Frequency Bias in the Load Flow page - Figure 21.2.3). The modified active power of each generator is then calculated according to the following equation:

𝑃𝑖 = 𝑃𝑖−𝑑𝑖𝑠𝑝𝑎𝑡𝑐ℎ + ∆𝑃𝑖

(21.1)

where, 𝑃𝑖 is the modified active power of generator 𝑖, 𝑃𝑖−𝑑𝑖𝑠𝑝𝑎𝑡𝑐ℎ is the initial active power dispatch of generator 𝑖 and ∆𝑃𝑖 is the active power change in generator 𝑖. The active power change of each generator (∆𝑃𝑖 ) will be determined by its corresponding primary controller gain value (𝐾𝑝𝑓 −𝑖 ) and the total frequency deviation.

∆𝑃𝑖 = 𝐾𝑝𝑓 −𝑖 · ∆𝑓

(21.2)

where, 𝐾𝑝𝑓 −𝑖 is the primary controller gain parameter of generator 𝑖 and ∆𝑓 is the total frequency deviation. The total frequency deviation (∆𝑓 ) can be obtained according to: ∆𝑃𝑇 𝑜𝑡 ∆𝑓 = ∑︀ 𝐾𝑝𝑓

(21.3)

where ∆𝑃𝑇 𝑜𝑡 corresponds to the active power change sum of every generator:

∆𝑃𝑇 𝑜𝑡 =

𝑛 ∑︁

∆𝑃𝑗

(21.4)

𝑗=1

Figure 21.2.2: Primary Frequency Bias

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Figure 21.2.3: Primary Frequency Bias (𝐾𝑝𝑓 ) Setting in the Load Flow Page of the Synchronous Machine Element (ElmSym) • According to Inertias: Immediately following a disturbance, the missing/excess power is delivered from the kinetic energy stored in the rotating mass of the turbines. This leads to a deceleration/acceleration and thus to a decrease/increase in the system frequency. The contribution of each individual generator towards the total additional power required is proportional to its inertia. If the Active Power Control option According to Inertias is selected in PowerFactory ’s load flow command, the power balance is established by all generators. Individual contributions to the balance are proportional to the inertia/acceleration time constant of each generator (defined on the RMSSimulation page of the synchronous generator typeŠs dialogue and depicted in Figure 21.2.4). This relation can be mathematically described as follows:

𝑃𝑖 = 𝑃𝑖−𝑑𝑖𝑠𝑝𝑎𝑡𝑐ℎ + ∆𝑃𝑖

(21.5)

where, 𝑃𝑖 is the modified active power of generator 𝑖, 𝑃𝑖−𝑑𝑖𝑠𝑝𝑎𝑡𝑐ℎ is the initial active power dispatch of generator 𝑖 and ∆𝑃𝑖 is the active power change in generator 𝑖. The active power change of each generator (∆𝑃𝑖 ) will be determined by its corresponding inertia gain (𝐾𝑝𝑓 −𝑖 ) and the total frequency deviation, as follows:

∆𝑃𝑖 = 𝐾𝑝𝑓 −𝑖 · ∆𝑓

(21.6)

where, 414

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21.2. TECHNICAL BACKGROUND ∆𝑓 is the total frequency deviation and 𝐾𝑝𝑓 −𝑖 is the inertia gain parameter of generator i, which can be calculated as:

𝐾𝑝𝑓 −𝑖 = 𝐽 · 𝜔𝑛 · 2𝜋

(21.7)

with

𝐽 = 𝑆𝑛 ·

𝑇𝑎𝑔𝑠 𝜔𝑛2

(21.8)

where, 𝐽 is the moment of Inertia, 𝜔𝑛 is the rated angular velocity, 𝑆𝑛 is the generator nominal apparent power and 𝑇𝑎𝑔𝑠 is the acceleration time constant rated to 𝑆𝑛

Figure 21.2.4: Inertia/Acceleration Time Constant Parameter of the Synchronous Machine Type (TypSym). RMS-Simulation Page

Figure 21.2.5 illustrates the different type of active power control.

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Figure 21.2.5: Frequency Deviation Following an Unbalance in Active Power Note: The Secondary Control option will take into account the participation factors of the machines defined within a Power-Frequency Controller (ElmSecctrl) in order to compensate for the frequency deviation. In such a case, the final steady state frequency is considered to be the nominal value (number 1 in Figure 21.2.5). The Primary Control option will take into account the frequency droop (MW/Hz) stated in every machine in order to determine the active power contribution. Depending on the power unbalance, the steady state frequency will deviate from the nominal value (number 2 in Figure 21.2.5). The According to Inertias option will take into account the inertia/acceleration time constant stated in every machine in order to determine its active power contribution. In this case, depending on the power unbalance, the steady state frequency will deviate from the nominal value (number 3 in Figure 21.2.5).

Reactive Power Control The reactive power reserves of synchronous generators in transmission networks are used to control the voltages at specific nodes in the system and/or to control the reactive power exchange with neighbouring network zones. In PowerFactory ’s load flow calculation, the voltage regulator of the generators has a voltage setpoint which can be set manually (defining a PV bus type as introduced in Section 21.2.1), or from an Automatic Station Controller (ElmStactrl). This Automatic Station Controller combines several sources of reactive power to control the voltage at a given bus. In this case the relative contribution of each reactive power source (such as generators and SVSs) is defined in the Station Controller dialogue. For further details about the use and definition of Automatic Station Controllers please refer to Appendix C: Technical References of Models, section C.5.1: Station Controller (ElmStactrl).

21.2.3

Advanced Load Options

Voltage Dependency of Loads All non-motor loads, as well as groups of non-motor loads that conform a sub-system, for example, a low-voltage system viewed from a medium voltage system, can be modelled as a “general load". Under “normal conditions" it is permissible to represent such loads as constant PQ loads. However under “abnormal conditions", for example during voltage collapse situations the voltage-dependency of the loads should be taken into account. Under such assumptions, PowerFactory uses a potential approach, as indicated by Equations (21.9) and (21.10). In these equations, the subscript 0 indicates the initial operating condition as defined in the input dialogue box of the Load Type.

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21.2. TECHNICAL BACKGROUND

(︃ 𝑃 = 𝑃0

(︂

𝑎𝑃 ·

𝑣 𝑣0

)︂𝑒_𝑎𝑃

𝑣 𝑣0

)︂𝑒_𝑎𝑄

(︂ + 𝑏𝑃 ·

𝑣 𝑣0

)︂𝑒_𝑏𝑃

𝑣 𝑣0

)︂𝑒_𝑏𝑄

(︂ + (1 − 𝑎𝑃 − 𝑏𝑃 ) ·

𝑣 𝑣0

)︂𝑒_𝑐𝑃 )︃

𝑣 𝑣0

)︂𝑒_𝑐𝑄 )︃

(21.9)

where, 𝑐𝑃 = (1 − 𝑎𝑃 − 𝑏𝑃 )

(︃ 𝑄 = 𝑄0

𝑎𝑄 ·

(︂

(︂ + 𝑏𝑄 ·

(︂ + (1 − 𝑎𝑄 − 𝑏𝑄) ·

(21.10)

where, 𝑐𝑄 = (1 − 𝑎𝑄 − 𝑏𝑄) By specifying the particular exponents (e_aP, e_bP, e_cP and e_aQ, e_bQ, e_cQ) the inherent load behaviour can be modelled. For example, in order to consider a constant power, constant current or constant impedance behaviour, the exponent value should be set to 0, 1 or 2 respectively. In addition, the relative proportion of each coefficient can be freely defined using the coefficients aP, bP, cP and aQ, bQ, cQ. For further information, please refer to the General Load technical reference in the Appendix C. Note: These factors are only considered if the “Consider Voltage Dependency of Loads" is checked in the Load-flow Command window. If no Load Type (TypLod) is assigned to a load, and the load flow is performed considering voltage dependency then the load will be considered as Constant Impedance.

Feeder Load Scaling In radially operated distribution systems the problem often arises that very little is known about the actual loading of the loads connected at each substation. The only information sometimes available is the total power flowing into a radial feeder. To be able to still estimate the voltage profile along the feeder a load scaling tool is used. In the simplest case the distribution loads are scaled according to the nominal power ratings of the trans-formers in the substations. Of course, more precise results are obtained by using an average daily, monthly or annual load. The previous is explained in Figure 21.2.6. Here, the measured value at the beginning of the feeder is stated to be 50 MW. Throughout the feeder there are three loads defined, of which only for one of them the load is precisely known (20 MW). The other two loads are estimated to be at around 10 MW each. PowerFactory ’s load flow analysis tool offers a special Feeder Load Scaling option so that the selected groups of loads (scalable loads) are scaled accordingly in order to meet the measured value.

Figure 21.2.6: Radial Feeder. Feeder Load Scaling Option DIgSILENT PowerFactory 15, User Manual

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CHAPTER 21. LOAD FLOW ANALYSIS In PowerFactory the following options for Feeder Load Scaling are available: • No scaling. • Scaling to measured apparent power. • Scaling to active power. • Scaling to measured current. • Scaling Manually. • Scaling to measured reactive power. • Scaling to measured power factor. Furthermore, the previous options can be combined; for example, scaling a selected groups of loads in order to meet a measured active power and power factor. Note: Loads that are to be scaled must be marked as such (Adjusted by Load Scaling), also the load scaling must be enabled in the load flow command option (Feeder Load Scaling).

The feeder load scaling process also can take into account the different type of load behaviour represented. Figure 21.2.7 illustrates just this. Here, a radial feeder consisting of three different type of loads is depicted (constant power, constant current and constant impedance). Under such assumptions, performing a load flow calculation with the option Consider Voltage Dependency of Loads (see previous Section), will result in calculated base quantities according to the type of load specified; for example, Ibase for the constant current load and Zbase for the constant impedance load. If in addition to the voltage dependency of loads, the Feeder Load Scaling option is enabled, the calculated scaling factor 𝑘 is applied according to the type of load defined in the feeder.

Figure 21.2.7: Feeder Load Scaling Factor Considering Different Behaviour of Loads

In PowerFactory , the amount of Feeder definitions is not limited to the amount of radial paths represented in the model. This means that the user can define more than one feeder element (ElmFeeder ) along the same radial path, as indicated in Figure 21.2.8 In this particular example, both Feeder 1 and 2 have the same specified orientation (→ Branch). While Feeder 1 is defined from the beginning of the radial path, Feeder 2 is defined after load L2. This particular type of feeder representation is termed as Nested Feeders. Since Feeder 1 is defined from the beginning of the radial path, every load (L1, L2, L3 and L4), as well as every feeder (Feeder 2) along this path will be considered as part of its definition. Since Feeder 2 is along the path defined for Feeder 1; Feeder 2 is nested in Feeder 1. 418

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21.2. TECHNICAL BACKGROUND In such cases, executing the load flow (with the option Feeder Load Scaling) will treat the two feeders as independent. Although nested, Feeder 1 will only try to scale loads L1 and L2 according to its setting, while Feeder 2 will scale loads L3 and L4. If Feeder 2 is placed Out of Service, then Feeder 1 will scale all the loads along the radial path (L1, L2, L3 and L4).

Figure 21.2.8: Nested Feeder Definition

For further information on Feeder definitions please refer to Chapter 13, Section 13.5 (Feeders). Load Scaling Factors Loads can be scaled individually by adjusting the Scaling Factor parameter located in the Load Flow page of the Load Element.Together with the scaling factor, the actual load is calculated as follows:

𝑃 = 𝑆𝑐𝑎𝑙𝑒 · 𝑃0

(21.11)

𝑄 = 𝑆𝑐𝑎𝑙𝑒 · 𝑄0

(21.12)

If voltage dependency of loads is considered then Equations (21.9) and (21.10) become;

(︃ 𝑃 = 𝑆𝑐𝑎𝑙𝑒 · 𝑃0

(︂

𝑎𝑃 ·

(︃ 𝑄 = 𝑆𝑐𝑎𝑙𝑒 · 𝑄0

𝑎𝑄 ·

(︂

𝑣 𝑣0

)︂𝑒_𝑎𝑃

𝑣 𝑣0

)︂𝑒_𝑎𝑄

(︂ + 𝑏𝑃 ·

(︂ + 𝑏𝑄 ·

𝑣 𝑣0

)︂𝑒_𝑏𝑃

𝑣 𝑣0

)︂𝑒_𝑏𝑄

(︂ + (1 − 𝑎𝑃 − 𝑏𝑃 ) ·

(︂ + (1 − 𝑎𝑄 − 𝑏𝑄) ·

𝑣 𝑣0

)︂𝑒_𝑐𝑃 )︃

𝑣 𝑣0

)︂𝑒_𝑐𝑄 )︃

(21.13)

(21.14)

Note: In order to consider a load in the feeder-load-scaling process, the option Adjusted by Load Scaling has to be enabled. In this case, the individual Scaling Factor of the load is not taken into account but overwritten by the feeder-scaling factor.

Additionally, loads can be grouped in zones, areas or boundaries so the scaling factor can be easily edited. In case of zones, there will be an additional Zone Scaling Factor. Coincidence of Low Voltage Loads In a low voltage system every load may consist of a fixed component with a deterministic amount of power demand plus a variable component comprising many different, small loads, such as lights, refrigerators, televisions, etc., whose power varies stochastically between zero and a maximum value. Under such conditions, PowerFactory uses a probabilistic load flow calculation, which is able to calculate both DIgSILENT PowerFactory 15, User Manual

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CHAPTER 21. LOAD FLOW ANALYSIS maximum and average currents as well as the average losses and maximum voltage drops. The probabilistic load flow calculation used by PowerFactory can be applied to any system topology, including meshed low-voltage systems. PowerFactory ’s probabilistic load flow calculation uses low voltage loads comprised of several customers with fixed and variable (stochastic) demand components. The maximum value of the variable component (which is dependent upon the number of customers, n) is described by the following formula:

𝑆𝑚𝑎𝑥 (𝑛) = 𝑛 · 𝑔(𝑛) · 𝑆𝑚𝑎𝑥

(21.15)

Where 𝑆𝑚𝑎𝑥 is the maximum variable load per connection (customer) and the function 𝑔(𝑛) describes the maximum coincidence of loads, dependent upon the number of connections, 𝑛. If a Gaussian distribution is assumed, the coincidence function is:

𝑔(𝑛) = 𝑔∞ +

1 − 𝑔∞ √ 𝑛

(21.16)

The average value of the variable component is:

𝑔(𝑛) = 𝑔∞ · 𝑆𝑚𝑎𝑥

(21.17)

Note: Low voltage loads can be represented in PowerFactory by Low Voltage Load (ElmLodlv ) elements which can be directly connected to terminals or by Partial Low Voltage Loads (ElmLodlvp) which are defined along transmission lines/cables (see the Definition of Line Loads section on the Load Flow page of transmission line/cable elements - ElmLne).

21.2.4

Temperature Dependency of Lines and Cables

The most important effect of the resistance of transmission line and cable conductors is the generation of losses (I2 R). Resistance will also affect the voltage regulation of the line due to voltage drop (IR). The resistance of a conductor is mainly affected by the operating temperature, and its variation can be considered practically linear over the normal range of operation (an increase in temperature causes an increase in resistance). In PowerFactory , the load flow calculation has two options for considering the Temperature Dependency of resistance for lines and cables: • at 20∘ C: When this option is selected, the load flow calculation uses the resistances (lines and cables) stated in the Basic Data page of the corresponding component (TypLne, TypCon, TypCab).

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Figure 21.2.9: Specification of the Resistance at 20ˇrC in the Basic Data page of the line type (TypLne) • at Maximum Operational Temperature: When this option is selected, the load flow calculation uses the corrected value of resistance, which is obtained with the following equation:

𝑅𝑚𝑎𝑥 = 𝑅20 [1 + 𝛼(𝑇𝑚𝑎𝑥 − 20∘ 𝐶)]

(21.18)

where, 𝑅20 is the resistance at temperature 20∘ C (Basic Data page of the corresponding type) 𝛼 is the temperature coefficient in 𝐾 −1 𝑇𝑚𝑎𝑥 is the maximum operational temperature (Load Flow page of the corresponding type) 𝑅𝑚𝑎𝑥 is the resistance at temperature 𝑇𝑚𝑎𝑥

Figure 21.2.10: Temperature Dependency Option Setting in the Load Flow page of the line type (TypLne) DIgSILENT PowerFactory 15, User Manual

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CHAPTER 21. LOAD FLOW ANALYSIS Additionally, the resistance temperature dependency can be defined by specifying either the resistance at maximum operational temperature, the temperature coefficient (1/K) or the conductor material (Aluminium, Copper or Aldrey). Table 21.2.1indicates the electrical resistivities and temperature coefficients of metals used in conductors and cables referred at 20∘ C/68∘ F (taken from IEC 60287-1 standard). Material Aluminium Copper

Resistivity (Ω-m) 2.8264 · 10−8 1.7241 · 10−8

Temperature coefficient [𝐾 −1 ] 4.03 · 10−3 3.93 · 10−3

Table 21.2.1: Electrical Resistivities and Temperature coefficients of Aluminium and Copper

21.3

Executing Load Flow Calculations

A load flow calculation may be initiated by: • Pressing the

icon on the main toolbar;

• Selecting the Calculation → Load Flow ... option from the main menu. An example of the load flow command dialogue is shown in Figure 21.3.1.

Figure 21.3.1: Load Flow Command (ComLdf ) Dialogue

The following pages explain the load flow command options. Following this, some hints are given regarding what to do if your load flow cannot be solved.

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21.3. EXECUTING LOAD FLOW CALCULATIONS The following pages describe the different load flow command (ComLdf ) options. for more detail technical background regarding the options presented here, please refer to Section 21.2.

21.3.1

Basic Options

Calculation Method AC Load Flow, balanced, positive sequence Performs load flow calculations for a single-phase, positive sequence network representation, valid for balanced symmetrical networks. A balanced representation of unbalanced objects is used (for further details please refer to Section 21.2.1). AC Load Flow, unbalanced, 3 Phase (ABC) Performs load flow calculations for a multi-phase network representation. It can be used for analyzing unbalances of 3-phase systems, e.g. introduced by unbalanced loads or non-transposed lines, or for analyzing all kinds of unbalanced system technologies, such as single-phase- or twophase systems (with or without neutral return). For further details please refer to Section 21.2.1. DC Load Flow (linear) Performs a DC load flow based on a set of linear equations, where the voltage angles of the buses are strongly related to the active power flow through the reactance of the individual components (for further details please refer to Section 21.2.1). Reactive Power Control This option is available only for AC load flow calculations. Automatic Tap Adjust of Transformers Adjusts the taps of all transformers which have the option Automatic Tap Changing enabled on the Load Flow page of their element dialogues. The tap adjustment is carried out according to the control settings defined in the transformer element’s dialogue (for further information please refer to the corresponding Technical Reference in the Appendix C). Automatic Shunt Adjustment Adjusts the steps of all switchable shunts that have the option Switchable enabled on the Load Flow page of the shuntŠs element dialogue (for further information please refer to corresponding Technical Reference in the Appendix C). Consider Reactive Power Limits Considers the reactive power limits defined by generators and SVSs. If the load flow cannot be solved without exceeding the specified limits, a convergence error is generated. If this option is not enabled, PowerFactory will print a warning message if any of the specified limits are exceeded. Consider Reactive Power Limits Scaling Factor This option is only available if Consider Reactive Power Limits is enabled. If selected, the reactive power limits of generators are scaled by the relaxation factors: Scaling factor (min) and Scaling factor (max) which are set on the Load Flow page of the generator element’s dialogue. Note that the reactive power limits of generators are also defined on the Load Flow page of the generator element’s dialogue by one of the following: maximum/minimum values, or according to the generatorŠs assigned type. Load Options DIgSILENT PowerFactory 15, User Manual

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CHAPTER 21. LOAD FLOW ANALYSIS Consider Voltage Dependency of Loads The voltage dependency of loads with defined voltage dependency factors (Load Flow page of the general- and complex load types) will be considered. Feeder Load Scaling Scales loads with the option Adjusted by Feeder Load Scaling enabled on the Load Flow page of their element dialogue by the Scaling Factor specified in the Load Scaling section of the feeder element. In this case, the Scaling Factor specified on the Load Flow page of load element dialogue is disregarded. Consider Coincidence of Low-Voltage Loads Calculates a ’low voltage load flow’ as described in Sections 21.2.3 and 21.3.6, where load coincidence factors are considered, so as to produce maximum branch currents and maximum voltage drops. Since coincidence factors are used, the result of low voltage analysis will not obey Kirchhoff’s current law. After the load flow has been successfully executed, maximum currents (Imax), maximum voltage drops (dumax) and minimum voltages (umin, Umin) are displayed in every branch element and at every busbar. The usual currents and voltages represent here average values of voltages and currents. Losses are calculated based on average values, and maximum circuit loading is calculated using maximum currents. Scaling Factor for Night Storage Heaters This is the factor by which the night storage heater power (as found in Low Voltage Load elements) is multiplied for all low voltage loads. Temperature Dependency: Line/Cable Resistances ...at 20∘ C The resistance of each line, conductor and cable will be according to the value stated in the Basic Data page of their corresponding type (at 20∘ C). ...at Maximum Operational Temperature The resistance of each line, conductor and cable will be adjusted according to the equation (21.18) described in Section 21.2.4 and the Temperature Dependency option stated in its corresponding type (TypLne, TypCon, TypCab).

21.3.2

Active Power Control

As explained in Section 21.2.2, PowerFactory ’s load flow calculation offers several options for maintaining power balance within the system under analysis. These options are: as Dispatched: If this option is selected and no busbar is assigned to the Reference Busbar (Reference Bus and Balancing section of the Active Power Control tab), the total power balance is established by one reference generator/external grid (“slack"-generator). The slack generator can be directly defined by the user on the Load Flow page of the target element. The program automatically sets a slack if one has not been already defined by the user. according to Secondary Control: Power balance is established by all generators which are considered by a “Secondary Controller" as explained in Section 21.2.2. Active power contribution is according to the secondary controller participation factors.

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21.3. EXECUTING LOAD FLOW CALCULATIONS according to Primary Control: Power balance is established by all generators having a Kpf -setting defined (on the Load Flow page of a synchronous machine element dialogue), as explained in Section 21.2.2. Active power contribution is according to the droop of every generator. according to Inertias: Power balance is established by all generators, and the contribution of each is according to the inertia (acceleration time constant) as explained in Section 21.2.2. Consider Active Power Limits: Active power limits for generators (as defined on the elementŠs Load Flow tab) participating in active power balance, will be applied. If this option is disabled, the active power output limits may be violated, in which case a warning is issued. This option is not available when the Active Power Control option is set to either as Dispatched or according to Inertias. Reference Bus and Balancing If as Dispatched is selected in the Active Power Control section of the tab, further options regarding the location of the reference busbar and the power balancing method are available: Balancing by Reference Machine: For each isolated area, the reference machine will balance the active power. Balancing by Load at Reference Busbar: This option is valid only when the reference bus bar has been defined. The load with highest active power injection at the reference bus will be selected as the slack (such as to balance the losses). Balancing by Static Generator at Reference Bus: As in the case of Balancing by Load, this option is valid only when the reference bus bar has been defined. The static generator with the highest nominal apparent power at the reference bus will be selected as the slack (i.e. to balance the losses). Distributed Slack by Loads: When this option is selected, only the loads which have the option Adjusted by Load Scaling enabled in the isolated area will contribute to the balancing. The distribution factor calculated for a load is determined by the following equation:

𝐾𝑖 =

𝑃𝑖𝑛𝑖,𝑖 𝑛 ∑︁ 𝑃𝑖𝑛𝑖,𝑗

(21.19)

𝑗=1

where, 𝑃𝑖𝑛𝑖 is the initial active power of the load.

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Figure 21.3.2: Adjusted by Load Scaling option in the Load Flow page of the Load element (ElmLod)

Distributed Slack by Generation (Synchronous Generators): All the synchronous generators in the isolated area will contribute to the balancing. As in the Distributed Slack by Loads option, the distribution factor calculated for a generator is determined by the following equation:

𝐾𝑖 =

𝑃𝑖𝑛𝑖,𝑖 𝑛 ∑︁ 𝑃𝑖𝑛𝑖,𝑗

(21.20)

𝑗=1

where, 𝑃𝑖𝑛𝑖 is the initial dispatched power of the generator. Interchange Schedule: This option is available only when the Distributed Slack by Loads or Distributed Slack by Generation is selected. It allows the loads or generation in a region to be scaled up or down to control the interchange of this region. The type of the region could be: Grids: Available for both distributed load slack and distributed generation. Zones: Available for both distributed load slack and distributed generation. Boundaries: Only available for distributed load slack. In the load flow page of the grid, zone or boundary elements, the following operational parameters are available: Consider Interchange Schedule: Enables or disables the Interchange Schedule for this region. By default this option is not selected. Scheduled active power interchange: States the expected interchange of the grid, zone or boundary. 426

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Figure 21.3.3: Consider Interchange Schedule option in the Load Flow page of the Grid element (ElmNet)

Reference Busbar: A different busbar to the one connecting the slack machine (or network) can be selected as a reference for the voltage angle. In this case the user must specify the value of the voltage angle at this selected reference bus, which will be remotely controlled by the assigned slack machine (or network). Angle: User-defined voltage angle for the selected reference busbar. The value will be remotely controlled by the slack machine (external network). Only available if a Reference Busbar has been selected.

21.3.3

Advanced Options

Load Flow Method As explained in Section 21.2.1, the nodal equations used to represent the analyzed networks are implemented using two different formulations: • Newton-Raphson (Current Equations) • Newton-Raphson (Power Equations, classical) In both formulations, the resulting non-linear equation systems must be solved using an iterative method. PowerFactory uses the Newton-Raphson method as its non-linear equation solver. The selection of the method used to formulate the nodal equations is user-defined, and should be selected based on the type of network to be calculated. For large transmission systems, especially when heavily loaded, the classical Newton-Raphson algorithm using the Power Equations formulation usually converges best. Distribution systems, especially unbalanced distribution systems, usually converge better using the Current Equations formulation. Load Flow Initialisation DIgSILENT PowerFactory 15, User Manual

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CHAPTER 21. LOAD FLOW ANALYSIS No Topology Rebuild Will speed up large sets of consecutive load flow calculations. Enabling this option means that the topology of the system will not be rebuilt when calculating the next load flow. If no topological changes will be made to the system between these consecutive load flow calculations, then this option may be enabled. No Initialisation (no flat-start) Initializes a load flow from a previously convergent solution (no flat-start). Consideration of transformer winding ratio Sets the manner in which voltage initialisation takes place at nodes. Reducing the relaxation factor results in an increased number of iterations, but yields greater numerical robustness. Tap Adjustment Method The direct method will include the tap controller models in the load flow calculation (i.e. in the internal loop involving the Newton-Raphson iterations). The new tap positions will then be calculated directly as a variable and are therefore known following a single load flow calculation. The stepped method will calculate a load flow with fixed tap positions, after which the required tap changes are calculated from the observed voltage deviations and the tap controller time constants. The load flow calculation is then repeated with the new tap positions, until no further changes are required. These tap adjustments take place in the outer loop of the calculation. Min. Controller Relaxation Factor The tap controller time constants are used in the automatic tap changer calculations to determine the relative speed of the various tap controllers during the load flow iterations. The relaxation factor can be used to slow down the overall controller speeds (in case of convergence problems, set a factor of less than 1.0), or to speed them up (for a faster load flow, set a factor of greater than 1.0). Station Controller Available on Advanced tab of the Advanced Options page. The options presented in this field determine the reactive power flow from generators participating in station controllers (ElmStactrl). Please refer to Appendix C.5.1 (Station Controller (ElmStactrl)) for information on station controllers and their control modes. Modelling Method of Towers with in/output signals The equations of the lines are modelled in the tower. It should be noted that selecting this option will result in slower performance. ignore couplings Inter-circuit couplings are ignored. equations in lines The constant impedance and admittance matrices are calculated by the tower and used to develop the equations of the lines. The equations involving coupling are modelled in the lines; consequently, using this option results in faster performance than using option with in/output signals. Use this load flow for initialization of OPF 428

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21.3. EXECUTING LOAD FLOW CALCULATIONS The results of this load flow calculation are used to initialize the OPF calculation.

21.3.4

Iteration Control

The options on this page relate to the non-linear equation solver and are therefore only available for PowerFactory ’s AC load flow calculation methods. Max. Number of Iterations for The load flow calculation comprises an inner loop involving the Newton-Raphson method (see Section 21.2.1), and an outer loop to determine changes to tap settings and to consider generator reactive power limits. Default values for the maximum number of iterations for these two loops are 25 iterations for the inner loop, and 20 iterations for the outer loop. Newton-Raphson Iteration - itrlx The inner loop of the load flow involves the Newton-Raphson iterations. This parameter defines the maximum number of iterations (typically 25). Outer Loop - ictrlx The outer loop of the load flow calculation will determine changes to the tap changer (depending on the tap adjustment method selected), and considers reactive power limits of generators, etc. These are adjusted in the outer loop and then a new iteration of the inner loop is started again (see Section 21.2.1). The maximum number of outer loop iterations (typically 20) is set by this parameter. Number of Steps - nsteps Problematic load flows with slow convergence may be improved by starting a load flow calculation for a low load level, and then increasing the load level in a number of steps. This is achieved by setting the Number of Stairs to a value greater than one. For example, nsteps = 3 begins a load flow at a load/generation level of 1/3 and the increases the power to 100% over two further steps. Max. Acceptable Load Flow Error for A higher precision or a faster calculation can be obtained by changing the maximum allowable error (i.e. tolerance). The values of the calculated absolute error for nodes, or the calculated relative errors in the model equations, e.g. voltage error of voltage controlled generators, are specified here. Nodes - errlf Maximum Iteration Error of Nodal Equations (typical value: 1 kVA). Model Equations erreq Maximum Error of Model Equations (typical value: 0.1%). Convergence Options Relaxation Factor A Newton-Raphson relaxation factor smaller than 1.0 will slow down the convergence speed of the load flow calculation, but may result in an increased likelihood of convergence for systems which are otherwise difficult to solve. Automatic Model Adaptation for Convergency The PowerFactory load flow calculation will always first try to find a solution using non-linear mathematical power system models. If a solution cannot be found, and this option is enabled, an adaptive algorithm will change these models slightly to make them more linear, until a solution is found. Any model adaptations are reported in the output window. Iteratively, starting from Level 1 up to Level 4, some types of models are adjusted in order to find a solution. The adaptations of the models for each level are the following: DIgSILENT PowerFactory 15, User Manual

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CHAPTER 21. LOAD FLOW ANALYSIS • Level 1 – Loads: All voltage dependency factors are set to minimum 0.5 – Generators and external networks: Reactive power limits are disabled – Transformers: tap control is disabled – Motors: The rotor resistance is not allowed to vary • Level 2 – Loads: All voltage dependency factors are set to minimum 0.8 – Generators and external networks: Reactive power limits are disabled – Transformers: tap control is disabled – Motors: The rotor resistance is not allowed to vary • Level 3 – Loads: All voltage dependency factors are set to minimum 2 – Generators and external networks: Reactive power limits are disabled – Transformers: tap control is disabled – Motors: The rotor resistance is not allowed to vary • Level 4 – Loads: All voltage dependency factors are set to minimum 2 – Generators and external networks: Reactive power limits are disabled and voltage equation are linearized – Transformers: tap control is disabled – Motors: The rotor resistance is not allowed to vary The models are not only lineralized but also simplified. If the user reached Level 4, he should better switch to the DC load flow method.

21.3.5

Outputs

Show Outer Loop messages Will print a report concerning the outer loop iterations, which may be used to solve convergence problems. Show Convergence Progress Report Will print a detailed report throughout the load flow calculation. When enabling this option the Number of reported buses/models per iteration can be stated. As a result, the required number of buses and models with the largest error will be reported (e.g. by stating 3, the 3 buses and models with the largest error will be printed out in the output window). As in the case of Outer Loop messages, this information can be useful in solving convergence problems. Show Verification Report Produces a table in the output window with a list of overloaded power system elements and voltage violations, according to the following values: Max. Loading of Edge Element Reference value of the maximum loading used by the Verification Report. Lower Limit of Allowed Voltage 430

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21.3. EXECUTING LOAD FLOW CALCULATIONS Reference value for the minimum allowed voltage used by the Verification Report. Upper Limit of Allowed Voltage Reference value for the maximum allowed voltage used by the Verification Report. Output can be pressed to edit Displays the report format definition that will be used. The arrow button or inspect the report settings. This option is only available if Show Verification Report is selected.

21.3.6

Low Voltage Analysis

As explained in Sections 21.2.3 and 40.4.1, low voltage loads (ElmLodlv and ElmLodvp) are modelled in PowerFactory with fixed and variable (stochastic) components. The parameters which define these fixed and variable components are set in both the load flow command dialogue (i.e. globally), and in the load typesŠ dialogues (i.e. locally) according to the settings defined below. Definition of Fixed Load per Customer The fixed load is the non-stochastic component of the load, which is not subject to coincidence factors. The active and reactive power defined in this field, multiplied by the number of customers (defined in the load element itself), are added to the fixed load component defined for each low voltage load (ElmLodlv and ElmLodvp). For further information about LV loads please refer to the corresponding technical references in the Appendix C. Definition of Variable Load per Customer The variable component of low voltage loads can be globally defined using the parameters in this section or by specifically defining LV load types for the target loads. The Max. Power per Customer is the independent maximum kVA per customer. This value, multiplied by the Coincidence Factor (ginf) (see Section 21.2.3), gives the “Average Power" per customer, which is used in load flow calculations. The ’total’ maximum variable power per load is calculated using the Max. Power per Customer, the Coincidence Factor (ginf ), and the number of customers (defined in the load element itself) as described in Section 21.2.3. For further information about LV loads please refer to the corresponding technical references in the Appendix C. Note: The factors defined in the section Definition of Variable Load per Customer are used as global data for the load flow calculation. If specific LV load types are defined, the locally-defined data in the type is used by the corresponding loads. For all other LV loads with no type assigned, the global data from the load flow command is used.

Voltage Drop Analysis For the consideration of the stochastic nature of loads, PowerFactory offers two calculation methods: • Stochastic Evaluation • Maximum Current Estimation The Stochastic Evaluation method is the more theoretical approach, and can also be applied to meshed network topologies. The Maximum Current Estimation method applies stochastic rules only for the DIgSILENT PowerFactory 15, User Manual

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CHAPTER 21. LOAD FLOW ANALYSIS estimation of maximum branch flows. Based on the maximum current flow in each branch element, maximum voltage drops are calculated and added along the feeder. Obviously, this method has its limitations in case of meshed LV networks.

21.3.7

Advanced Simulation Options

This page, as shown in Figure 21.3.4, is not only important for load flow but also for other calculation functions such as transient simulation. Utilizing the options on this page can result in improved performance; i.e. the speed of a transient simulation may improved when protection devices are neglected in the calculation.

Figure 21.3.4: Advanced Simulation Options in the load flow command dialogue

Consider Protection Devices Calculates the tripping times for all modelled relays and fuses. This will also show the load currents in the overcurrent plots and/or the measured impedance in the R-X diagrams. Disabling this option will speed up the calculations. Ignore Composite Elements Disables all controller models. The panes Models Considered and Models Ignored are used to disable specific groups of controller models. Model names can be moved between these panes by either double-clicking on them or by selecting them and using the arrow buttons. Enabling this option may result in faster convergence, or an increased likelihood of convergence for systems which are otherwise difficult to solve.

21.4

Result Analysis

In PowerFactory the results can be displayed directly in the single line diagram, in tabular form or by using predefined report formats. Also available are several diagram colouring options in other to have a “quick" overview of the results.

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21.4.1

Viewing Results in the Single Line Diagram

Once a load flow calculation has been successfully executed, the result boxes shown in the single-line diagram will be populated. There is a result box associated with each “side" of an element. So for example a load has one result box, a line two result boxes, and a three-winding transformer three result boxes. In PowerFactory these elements are collectively called edge elements. In addition, there are result boxes for nodes or buses. The information shown inside a result box depends on the element to which it is associated. There are a few predefined formats for edge elements and a few predefined formats for buses. In order to see the selection, first perform a load flow, then, from the main menu, select Output → Results for Edge Elements or Output→ Results for Buses. These menu options will show the list of available result box formats. Alternatively, you can select (click) inside a result box on the single-line diagram, then right-click and from the context sensitive menu choose Format for Edge Elements or in case of a node Format for Nodes. Figure 21.4.1 serves as an example.

Figure 21.4.1: Selecting the Result Box from the Single Line Diagram.

Besides these predefined formats the result boxes can be formatted in order to display selected variables. By right-clicking on one of the result boxes and selecting the option Edit Format for Edge Elements and afterwards pressing the Input Mode button three options will be available: Predefined Variables, User Selection or Text Editor. The “User Selection" option will allow the selection of any of the available variables.

21.4.2

Flexible Data Page

Once a load flow calculation has been successfully executed, pressing the Edit Relevant Objects for Calculation button ( ) located on the main menu will prompt a submenu with icons for all classes that are currently used in the calculation. Clicking any of the class-icons will open a browser with all elements of that class that are currently used in the calculation. The left-most tab-page at the bottom of the browser is the Flexible Data tab page. Click on this tab page to show the flexible data. To change the columns in the flexible page, press the Define Flexible Data button ( ). This will bring a selection window where the set of variables can be edited. In the left pane the available variables will be shown or buttons will move the selected while the right pane will list the selected variables. Pressing the variable from the one pane to the other pane.

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21.4.3

Predefined Report Formats (ASCII Reports)

In PowerFactory there are predefined report formats also called ASCII reports, available to the user. These ASCII reports can be created by pressing the Output Calculation Analysis button ( ) located on the main menu (a load flow must be calculated first). This will bring a selection window in which the user can select a specific type of report. Some reports like the “Complete System Report" will have various options which the user can set. The report selection window also shows the report definition which will be used for the selected report. Pressing Execute will write the report to the output window. Although the reports are already predefined, the user has the possibility of modifying the reports if required (by clicking on the blue arrow pointing to the right of the used format definition). A Verification Report can be also printed out automatically each time a load flow calculation is executed (see Section 40.4.2).

21.4.4

Diagram Colouring

When performing load flow calculations, it is very useful to colour the single line-diagram in order to have a quick overview of the results, for example if elements have a loading above 90% or if the voltages of the busbars are outside the specified limits. In PowerFactory there is the option of selecting different colouring modes according to the calculation performed. If a specific calculation is valid, then the selected colouring for this calculation is displayed. As an example, if the user selects the colouring mode Zones for No Calculation and Low and High Voltage/Loadings for the load flow calculation, then the initial colouring will be according to Zones. However, as soon as the load flow is calculated, the diagram will be coloured according to Low and High Voltage/Loadings. If the load flow calculation is reset or invalid, the colouring mode switches back to Zones. The Diagram Colouring has also a 3-priority level colouring scheme also implemented, allowing colouring elements according to the following criteria: 1𝑠𝑡 Energizing status, 2𝑛𝑑 Alarm and 3𝑟𝑑 “Normal" (Other) colouring. Energizing Status If this check box is enabled “De-energized" or “Out of Calculation" elements are coloured according to the settings in the “Project Colour Settings". The settings of the “De-energized" or “Out of Calculation" mode can be edited by clicking on the Colour Settings button. Alarm If this check box is enabled a drop down list containing alarm modes will be available. It is important to note here that only alarm modes available for the current calculation page will be listed. If an alarm mode is selected, elements “exceeding" the corresponding limit are coloured. Limits and colours can be defined by clicking on the Colour Settings button. “Normal" (Other) Colouring Here, two lists are displayed. The first list will contain all available colouring modes. The second list will contain all sub modes of the selected colouring mode. The settings of the different colouring modes can be edited by clicking on the Colour Settings button. Every element can be coloured by one of the three previous criteria. Also, every criterion is optional and will be skipped if disabled. Regarding the priority, if the user enables all three criterions, the hierarchy taken into account will be the following: “Energizing Status" overrules the “Alarm" and “Normal Colouring" mode. The “Alarm" mode overrules the “Normal Colouring" mode.

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21.5. TROUBLESHOOTING LOAD FLOW CALCULATION PROBLEMS

21.4.5

Load Flow Sign Convention

By default, PowerFactory has the following load flow sign convention (Mixed Mode): Branches: Power Flow going out of the Busbar is positive while going into the busbar is negative. Loads: Power Flow going out of the Busbar is positive while going into the busbar is negative. Here, the term load considers “General Loads", “Low-Voltage Loads", “Motors", “Shunts/Filters" and “SVS". A synchronous machine stated as a “Motor" will have also this sign convention. Generation: Power Flow going out of the Busbar is negative while going into the busbar is positive. Here, the term Generation considers “Generators", “External Grids", “Static Generators" and “Current and Voltage Sources". An asynchronous machine stated as a “Generator" will have also this sign convention.

21.5

Troubleshooting Load Flow Calculation Problems

In general, if a solution can be found (in other words, the network is mathematically solvable), PowerFactory will find a solution. In some cases the user may have made an error which will not allow a solution to be found; such as a large load causing a voltage drop so large that a voltage collapse results. In a real-world power system the same problem would be found. When creating a network for the first time it is best to enter the data for only a small part or ’path’ of the network and solve the network by calculating a load flow. PowerFactory has a data verification process in which certain checks are performed, such as whether a line is connected between nodes of the same voltage; and the correct voltage orientation of transformers, etc. Typical reasons for non-convergence in the load flow are: • Data model problem. • Too many inner loop iterations. • Too many outer loop iterations. • Excessive mismatch. • Tap hunting. Clearly this is not an exhaustive list of problems, but these are the main causes of non-convergence and that will be discussed in this section.

21.5.1

General Troubleshooting

The place to search for the causes of the non-convergence problem is in the PowerFactory output window. Here, there can be three different types of messages printed out, which are the following: Info messages (green/blue):

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CHAPTER 21. LOAD FLOW ANALYSIS Information detailing the load flow convergence (inner and outer loop iterations). Information of generators with reactive power compensation at output limit. Information on the total number of isolated areas (see 21.5.3). Warning messages (dark red): Warning messages do not need to be corrected for the load flow to solve, however they could give you an indication of where the problem is. Take note of the warning messages and evaluate them in terms of your system. Important warnings, such as “Exceeding Mvar limit range" may not be acceptable. “Unsupplied Areas" messages indicate that an isolated area with “Consumers" (such as loads and motors) is without a generator, power source or external supply. Error messages (red): Error messages must be corrected for a load flow to solve. Error messages could be generated by PowerFactory ’s data checking function, which include messages such as DIgSI/err - missing type! In most cases the messages have links to the data base and graphic. The following options can be performed in order to trace errors: • Use the data-verification tool (

).

• Once errors have been detected, open the problematic element dialogue window by double clicking on the name directly from the output window. Or alternatively, right click mouse button over the name and select edit, or edit and browse, or mark in graphic. The amount of information being printed to the PowerFactory output window can be changed by the user. Once error messages have been analyzed and corrected and the load flow still does not solve, the user may want to print more detailed information on the convergence progress. Tick the Show Convergence Progress Report option found in the Outputs page of the load flow dialogue (refer to Section 40.4.2). This will print messages to the output window that can provide clues as to where the convergence problems may lie. The single line graphic can also be coloured to show low and high voltages and overloadings. This will also provide a good indication of possible problems. Look at the undervoltage nodes and overloaded elements and investigate why they are overloaded; look at load setpoints, line lengths and line type data (the impedances may be too high, for example). Note: As explained above, there are 3 different types of messages that are printed to the output window: warning, error and information messages. Only error messages must be corrected for a load flow to solve. Take note of the warning messages and evaluate them in terms of your system, however these do not need to be corrected for the load flow to solve. “Unsupplied Areas" means that an isolated area with “Consumers" is without a generator, power source or external supply.

If there is still no convergence then set the option Out of Service for most of the elements (see each elements Basic Data tab). Following this, bring these elements back into service, one at a time, from the source element downwards, performing a load flow calculation each time. When experiencing large unbalances, such as when there are a number of single or dual phase elements, or when using power electronics elements, select the Newton-Raphson (Current Iteration) option on the Advanced page of the load flow dialogue.

21.5.2

Data Model Problem

In PowerFactory , there are three different levels of data verification implemented: 436

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21.5. TROUBLESHOOTING LOAD FLOW CALCULATION PROBLEMS Parameter Level: Checks the consistency of the input parameter; for example, entering a negative value in the length of the line will prompt an error message. Other verifications implemented include checking if the parameter imputed is within certain limits. Object Level: Checks the consistency of the data being imputed from the component itself; for example, checking if the magnetizing losses of a transformers are less that the total magnetizing apparent power (i.e. magnetizing current), checking if the inputting of the manufactureŠs data results in a feasible torque-slip characteristic, etc. System Level: Checks the consistency of the data being imputed from a system point of view; for example, checking if lines/cables are connected between the same voltage levels, checking if the HV/MV/LV side of transformers is compatible with the voltage level of busbars, checking if there are missing types, etc. Data model problems can normally be fixed easily as the output window message refers directly to the element causing the problem. Typical cases of data model problems are: DIgSI/err - missing type!: It indicates that input data (electrical data defined in types) is missing. In most cases the messages have links to the data base and graphic. DIgSI/err - Check control conditions!: It normally appears when more than one controller (for example a station controller) is set to control the same element, such as the same busbar. PowerFactory will print the name of the controlled element to the output window. Starting from the controlled element, access the controllers to fix the problem. DIgSI/err - Line connected between different voltage levels!

21.5.3

Some Load Flow Calculation Messages

DIgSI/info - Grid split into 182 isolated areas An “isolated area" indicates that a busbar or a group of busbars are not connected to the slack busbar. An isolated generator or an isolated external grid forms an isolated area. An isolated area refers basically to nodes. Each isolated area is assigned an index (Parameter name b:ipat under ElmTerm Basic) and needs a load flow reference (slack) of its own. These busbars can be found colouring the single line graphic according to isolated grids. DIgSI/wrng - 2 area(s) are unsupplied An ”unsupplied area” is an isolated area with ”Consumers” (such as loads and motors) without a generator, power source or external supply. That is U=0 and I=0. Unsupplied areas belong to the group of isolated areas. The unsupplied areas can be identified by displaying the following parameter in the ”Consumers” components (loads, synchronous/asynchronous motors): • 𝑟 : 𝑏𝑢𝑠1𝑏 : 𝑖𝑝𝑎𝑡. Gives the Index of the isolated area • 𝑟 : 𝑏𝑢𝑠1 : 𝑏 : 𝑖𝑚𝑜𝑑𝑒 = 0. Indicates there is no slack in the isolated area therefore indicating its unsupplied. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 21. LOAD FLOW ANALYSIS • 𝑟 : 𝑏𝑢𝑠1 : 𝑏 : 𝑖𝑚𝑜𝑑𝑒 > 0. Indicates the area is supplied. DIgSI/err - Outer loop did not converge.

Maximum number of iterations reached

Fore some hints on this type of error please refer to Section 21.5.5.

21.5.4

Too many Inner Loop Iterations

Too many inner loop iterations are “normally" related to voltage stability (voltage collapse) problems. For example, a large load causing voltage drops so high that a voltage collapse results. Also very weak connections resulting from faults or outages may lead to voltage collapse during contingency analysis. The problem will not only be found in the simulation but would be found in the real world as well! The main causes leading to a voltage stability problem can be summarized as follows: • Excessive active power demand leading to a high voltage drop. • Lack of reactive power compensation. Diagnosis and Solution: The main source of Information is the output window. Enable the Show Convergence Progress Report option found in the Outputs page of the load-flow dialogue. Analyze the convergence of the inner loop iterations: check the progress in the load flow error for nodes and model equations: • Are they increasing or decreasing? • If the error is not continuously decreasing, it could be an indication of a voltage stability problem. • Identify the element (load, generator) with high convergence error. Use the Mark in Graphic option to identify the zone of the network having the problem. Several possible countermeasures can be undertaken to fix the problem: • Use the Iteration Control options on the load flow command (increasing the number of stairs as the first option, typically to 3). • Load shedding: disconnect the load identified as responsible for the high convergence error. • Connect additional reactive power compensation. • Using the flexible data page, check if there are any heavily loaded circuits, these indicate weak connections. Once the load flow converges, check if there are areas with voltages with high deviation from operating voltages. Excessive Mismatch Where there is a large mismatch between demand and generation (> 15%) the load flow is unlikely to converge. This is typified by a large number of iterations followed by warnings or errors such as: No convergence in load flow! Control Conditions!

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21.5. TROUBLESHOOTING LOAD FLOW CALCULATION PROBLEMS Depending on the size of the mismatch, the failure might occur during the initial Newton-Raphson or during subsequent outer loop iteration. There may also be a large number of maximum/minimum reactive power reached and transformer tap statements. Solution: • Set the option Show Convergence Progress Report on the Outputs page and observe which elements are having the highest mismatches. These elements should be closely checked. • Check the mismatch on the Reference machine by performing a DC load flow as Dispatched allowing for normal losses. Rebalancing the network might alleviate convergence problems.

21.5.5

Too Many Outer Loop Iterations

Outer loops iterations are required to calculate discrete tap positions of transformers, number of steps of switchable reactive power compensation, etc. in order to match the voltage profile or reactive power control specified by the user. Too many outer loop iterations is referring to a solution that is too far away from the starting point (default tap positions) to converge in the allowed number of outer loop iterations. Diagnosis and Solution: The outer-loop does the following: • Increasing/Decreasing discrete taps. • Increasing/Decreasing switchable shunts. • Limiting/Releasing synchronous machines to/from max/min reactive power limits. If the outer loop does not converge, it can have the following reasons: • Tap upper and lower limits are too close, so that the voltage can never be kept in the desired range. • The same with switchable shunts. • Other toggling effects, for example synchronous machine limits and tap positions don’t find a stable solution. The main source of Information is the output window. Check first the following: • Is the number of messages reducing with each outer loop iteration? The following messages in the output window may indicate a problem and lead to a non-convergent solution. Maximum/minimum tap position reached DIgSI/pcl - -------------------------------DIgSI/pcl - ’$ \ $ .... $\ $Transformer.ElmTr2’: DIgSI/pcl - Maximum Tap Position reached DIgSI/pcl - -------------------------------The message indicates that more/less reactive power is required at this location (the tap is at maximum/minimum position). The message indicates therefore an area in the network where a lack/excess of reactive power is likely to happen. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 21. LOAD FLOW ANALYSIS Reactive power limit left DIgSI/pcl - -------------------------------DIgSI/pcl - ’$ \ $.... $\ $ Generator.ElmSym’: DIgSI/pcl - Reactive Power Limit left DIgSI/pcl - -------------------------------This will lead to a convergence error. A load flow calculation without considering reactive power limits may find a solution. Check then required reactive power at the generator. Maximum/minimum reactive power reached. DIgSI/pcl - -------------------------------DIgSI/pcl - ’$\ $....$ \ $ Generator.ElmSym’: DIgSI/pcl - Maximum Reactive Power Reached DIgSI/pcl - -------------------------------Basically means that there is no regulation margin in the specified generators. In general the results from the last iteration should be available to view on the output window. • Is the mismatch always in the same (or similar) location? • How far away from the solution was the original starting point? All actions (except for shunt switching) are displayed in the output window by blue messages. Observing these messages allows to conclude what the reason for the convergence problem was, for example if a synchronous machine toggles between limited/released, the problem is related to this particular machine. • If no toggling can be observed, increasing the maximum number of outer iteration loops may help. • If the load flow converges, improve the convergence of subsequent calculations by saving the tap positions ( ). If the load flow does not converge after a large number of iterations then other methods of improving convergence are: • Use the direct method on the advanced options page of the load flow command. • Set the maximum tap changes per iteration to be a small number, for example 1. This will result in PowerFactory not changing all tap changers at once by several steps but only by maximum of 1 step at once. In larger networks this is often improving the convergence. • Perform a load flow without automatic taps and shunt adjustment. If the load flow does not converge in this case, it could be an indication that the load is exceeding the voltage stability limits, thus the load is too high. Tap Hunting Tap hunting can be easily recognised when one or more transformers oscillate between tap positions until the number of outer loop iterations is exhausted. This is normally due to the transformer (controller) target voltage dead band being smaller than the transformer tap step size. The messages below indicate an example of a single transformer Tap-Hunting:

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21.6. LOAD FLOW SENSITIVITIES

Figure 21.5.1

This problem of no converging load-flow with the stepped tap changing method is caused by a slightly different way of the iteration to reach the correct tap position and load-flow results. This might result in a non-convergence in the outer loop, when the controller range (Vmax-Vmin) of the tap changer is near to the value of the additional voltage per tap. Solution: • Change the minimum relaxation factor on the Advanced Options page of the load flow command to a smaller value. This might help the load flow to converge. • Check if the dead bands of the target or controlled busbars of the corresponding transformers are correctly set. Also check if the tap changer data on the load flow page of the transformer type is correct. • Disable the automatic tap changing of the transformers where tap hunting occur. Run the load flow (it should converge in this case!) and then check the sensitivity of the tap changer increasing and decreasing the tap position by one step. Verify the results against the dead band of the target busbar.

21.6

Load Flow Sensitivities

PowerFactory ’s Load Flow Sensitivities (ComVstab) command is shown in Figure 21.6.1. This command performs a voltage sensitivity analysis based on the linearization of the system around the operational point resulting from a load flow calculation (as explained in Section 21.6.3). The ComVstab command is accessible by the following means: • clicking on the Change Toolbox icon ( ComVstab icon ( ); or

)and selecting Additional Tools and then clicking on the

• right-clicking on a busbar/terminal or transformer and selecting Calculate → Load Flow Sensitivities... . In this case the command will be automatically set to calculate the sensitivity to power injections/tap changes on the selected busbar/transformer. The selected terminal/transformer will be automatically set in the Busbar (or Transformer ) reference. DIgSILENT PowerFactory 15, User Manual

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Figure 21.6.1: Load Flow Sensitivities Command (ComVstab) Dialogue

21.6.1

Load Flow Sensitivities Options

The options available for the Load Flow Sensitivities command (Figure 21.6.1) are: Initialization Load Flow: Displays which load flow command will be used to initialize the sensitivity analysis. If no load flow calculation has been executed before opening the Load Flow Sensitivities (ComVstab) command, or if the calculation has been reset, the Load Flow displays the most recently executed load flow command in the active study case. Sensitivities Diagonal Elements Only: The effect of the injections of ∆P and ∆Q at each busbar are evaluated for the busbar itself (effect on voltage magnitude (𝜕𝑣𝑖 /𝜗𝑃𝑖 ), (𝜕𝑣𝑖 /𝜕𝑄𝑖 ), and on voltage angle (𝜕𝜙𝑖 /𝜕𝑃𝑖 ), (𝜕𝜙𝑖 /𝜕𝑃𝑖 ) for each busbar) and the corresponding adjacent branches. In this mode, the calculated sensitivities (𝜕𝑃𝑛 /𝜕𝑃𝑖 ), (𝜕𝑄𝑛 /𝜕𝑃𝑖 ), (𝜕𝑃𝑛 /𝜕𝑄𝑖 ), and (𝜕𝑄𝑛 /𝜕𝑄𝑖 ) in the branches (index 𝑛) always refer to derivations 𝜕/𝜕𝑃𝑖 and 𝜕/𝜕𝑄𝑖 of the adjacent buses (index 𝑖). This means that the sensitivities are calculated for all busbars and for all branches, according to variations in power (∆P and ∆Q) at the directly connected busbars. Sensitivity to a Single Busbar: The effect of the injections of ∆P and ∆Q at the selected busbar are calculated for the whole network (i.e. for all buses and branches). The target busbar can be selected using the Busbar button ( ) located at the bottom of the dialogue. Alternatively, the target bus can be selected in the single line graphic by right-clicking on it and selecting Calculate → Load Flow Sensitivities from the context-sensitive menu. The sensitivities of all busbars and branches are calculated according to variations in power (∆P and ∆Q) at the selected busbar. Sensitivity to a Single Transformer Tap Position: 442

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21.6. LOAD FLOW SENSITIVITIES This option evaluates the effect of changing the tap position of a selected transformer in the network. The sensitivities 𝑑𝑃/𝑑𝑡𝑎𝑝 [𝑀 𝑊/𝑡𝑎𝑝𝑠𝑡𝑒𝑝], 𝑑𝑄/𝑑𝑡𝑎𝑝 [𝑀 𝑣𝑎𝑟/𝑡𝑎𝑝𝑠𝑡𝑒𝑝] for branches, and 𝑑𝑝ℎ𝑖/𝑑𝑡𝑎𝑝 [𝑑𝑒𝑔/𝑡𝑎𝑝𝑠𝑡𝑒𝑝], 𝑑𝑣/𝑑𝑡𝑎𝑝 [𝑝.𝑢./𝑡𝑎𝑝𝑠𝑡𝑒𝑝] for buses are calculated. The target transformer can be selected using the Transformer button ( ) located at the bottom of the dialogue. Alternatively, the target transformer can be selected in the single line graphic by right-clicking on it and selecting Calculate → Load Flow Sensitivities from the context-sensitive menu. Modal Analysis: This option performs an eigenvalue calculation on the sensitivity matrix as explained in Section 21.6.3. The number of eigenvalues to be calculated is defined in the Number of Eigenvalues field at the bottom of the dialogue. The eigenvalues are always calculated in order of their largest magnitude, so selecting n eigenvalues will display the n eigenvalues in descending order according to magnitude (note that the larger the number of desired eigenvalues, the longer the calculation will take). In the Display Results for Mode field, the user can specify the number of a specific eigenvalue, for which the stability behaviour (i.e. the eigenvectors and participation factors) is to be analyzed. The algorithm then additionally calculates the (𝜕𝑃/𝜕𝑄) , (𝜕𝑄/𝜕𝑄) (branch sensitivities) and the (𝜕𝑣/𝜕𝑄), (𝜕𝜙/𝜕𝑄) (bus sensitivities) which correspond to the mode specified (see Section 21.6.3 for further technical background).

21.6.2

Load Flow Sensitivities Execution and Results

When the ComVstab command has been configured and the Execute button has been pressed, the program calculates several sensitivity factors such as (𝜕𝑣𝑖 /𝜕𝑃𝑖 ) ,(𝜕𝑣𝑖 /𝜕𝑄𝑖 ) , (𝜕𝜙𝑖 /𝜕𝑃𝑖 ), (𝜕𝜙𝑖 /𝜕𝑄𝑖 ) etc., according to the selected options, for buses and branch elements. Upon completion of the sensitivity factor calculation, the following message appears in the output window: DIgSI/info - Load Flow Sensitivities calculated! The calculated results can be displayed via the Flexible Data Page (see Section 10.6) by selecting the sensitivities from the load flow variables (Variable Set: Current, Voltages and Powers). The names of the variables correspond to the calculated derivations, i. e. the result of the expression (𝜕𝜙𝑖 /𝜕𝑃𝑖 ) is stored in the variable named 𝑑𝑣𝑑𝑃 ; and likewise the result of the expression (𝜕𝜙𝑖 /𝜕𝑄𝑖 ) is stored in the variable 𝑑𝑝ℎ𝑖𝑑𝑄. When the Modal Analysis option is selected, the calculated eigenvalues are displayed (in descending order according to magnitude) in the output window. The eigenvectors and participation factors can be displayed using the Flexible Data Page.

21.6.3

Technical Background

PowerFactory ’s Load Flow Sensitivities function (ComVstab) performs a static voltage stability calculation as described below. Linearizing the load flow equations around the actual operating point leads to the following equation system: [︂

𝐽𝑃 𝜗 𝐽𝑃 𝑣 𝐽𝑄𝜗 𝐽𝑃 𝑣

]︂ [︂

𝜕𝜗 𝜕𝑣

]︂

[︂ =

𝜕𝑃 𝜕𝑄

]︂ (21.21)

The equation system in (21.21) shows that changes in the voltage magnitude and angle due to small changes in the active and reactive power can be directly calculated from the load flow Jacobian matrix. For example if ∆P is set to 0, the sensitivities of the type dv/dQ are calculated from (21.21) according to: DIgSILENT PowerFactory 15, User Manual

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−1 𝜕𝑣 = 𝐽̃︀𝑄𝑣 𝜕𝑄 = 𝑆𝑣𝑄 𝜕𝑄

(21.22)

𝐽̃︀𝑄𝑣 = −𝐽𝑄𝜗 𝐽𝑃−1 𝜗 𝐽𝑃 𝑣 + 𝐽𝑄𝑣

(21.23)

where:

As can be seen from (21.22), the variation of voltage magnitude at each busbar can be described by a linear combination of small reactive power variations according to: 𝜕𝑣𝑖 = 𝑆𝑖1 𝜕𝑄1 + · · · + 𝑆𝑖𝑛 𝜕𝑄𝑛

(21.24)

In this case the diagonal elements 𝑆𝑖1 of 𝑆 represent the voltage variation at bus i due to a variation of reactive power at the same point. The non-diagonal elements 𝑆𝑖𝑗 describe the voltage variation at busbar 𝑖 due to the variation in reactive power at a different point on the network. Positive dv/dQ sensitivity indicates stable operation. High sensitivity means that even small changes in reactive power cause large changes in the voltage magnitude; therefore the more stable the system, the lower the sensitivity (high voltage sensitivities are indicative of weak areas of the network). Note: Recall that in HV networks branches are predominantly reactive. Voltage magnitudes depend primarily on reactive power flows and voltage angles depend on active power bus injections.

The sensitivity analysis can be extended in order to determine the active and reactive power variations on branches (in the PowerFactory network model all components carrying a flow, i.e. lines, transformers, generators are regarded as branches) due to variations in active and reactive power busbar injections. In this case the sensitivities are calculated using the branch-node Jacobian matrix. By applying a modal transformation to (21.22) the dV/dQ sensitivity can be expressed as an uncoupled system of the form: ̃︀ = 𝑆̃︀𝑣𝑄 𝜕 𝑄 ̃︀ 𝜕̃︀ 𝑣 = 𝑇 −1 𝑆𝑣𝑄 𝑇 𝜕 𝑄

(21.25)

̃︀ 𝑣 = 𝑇 𝑣̃︀ and 𝑄 = 𝑇 𝑄

(21.26)

where:

In (21.25), 𝑆̃︀𝑣𝑄 is a diagonal matrix whose elements correspond to the eigenvalues of the sensitivity matrix, 𝑆𝑣𝑄 , from (21.22). Therefore, the voltage variation at each mode depends only on the reactive power variation at the same mode: ̃︁𝑖 𝜕 𝑣̃︀𝑖 = 𝜆𝑖 𝜕 𝑄

(21.27)

The eigenvalues 𝜆𝑖 , which are real, provide the necessary information about the voltage stability of the system. If 𝜆𝑖 is positive, the modal voltage increase and the modal reactive power variations are in the same direction and the system is therefore stable. The magnitude of the eigenvalue indicates how far/close one voltage mode is to instability. In (21.25), 𝑇 = [𝜐1 . . . 𝜐𝑛] corresponds to the matrix of right eigenvectors of 𝑆𝑣𝑄 , while 𝑇 −1 corresponds to the left eigenvectors matrix:

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⎤ 𝜔1𝑇 ⎢ ··· ⎥ ⎥ =⎢ ⎣ ··· ⎦ 𝜔𝑛𝑇 ⎡

𝑇 −1

(21.28)

The participation factor of bus 𝑘 to mode 𝑖 is defined by the product of the 𝑘𝑡ℎ component of the left and right eigenvector of mode 𝑖: 𝑃𝑖𝑘 = 𝜔𝑖𝑘 𝜐𝑖𝑘

(21.29)

The sum of the participation factors of all nodes corresponds to the scalar product of the left and right eigenvector, and is therefore equal to one. In this sense, the participation factor gives an indication of the extent of the influence the variation of active power on a node has on a voltage mode.

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Chapter 22

Short-Circuit Analysis 22.1

Introduction

Power systems as well as industrial systems are designed so that loads are supplied safely and reliably. One of the major aspects taken into account in the design and operation of electrical systems is the adequate handling of short-circuits. Although systems are designed to stay as free from short circuits as possible, they can still occur. A short-circuit condition generally causes large uncontrollable current flows, which if not properly detected and handled can result in equipment damage, the interruption of large areas (instead of only the faulted section) as well as placing personnel at risk. A well-designed system should therefore isolate the short-circuit safely with minimal equipment damage and system interruption. Typical causes of short-circuits can be the following: • Lightning discharge in exposed equipment such as transmission lines. • Premature ageing of the insulation due mainly to permanent overloading, inappropriate ventilation, etc. • Atmospheric or industrial salt “Build-Up" in isolators. • Equipment failure. • Inappropriate system operation. One of the many applications of a short-circuit calculation is to check the ratings of network equipment during the planning stage. In this case, the planner is interested in obtaining the maximum expected currents (in order to dimension equipment properly) and the minimum expected currents (to aid the design of the protection scheme). Short-circuit calculations performed at the planning stage commonly use calculation methods that require less detailed network modelling (such as methods which do not require load information) and which will apply extreme-case estimations. Examples of these methods include the IEC 60909/VDE 0102 method [11], the ANSI method and the IEC 61363 method [9] for AC short circuit calculation and the IEC 61660 method [8] and ANSI/IEEE 946 method [5] for DC short circuit calculation. A different field of application is the precise evaluation of the fault current in a specific situation, such as to find out whether the malfunction of a protection device was due to a relay failure or due to the consequence of improper settings (for example an operational error). These are the typical applications of exact methods such as the superposition method (also known as the Complete Method), which is based on a specific network operating point. The short-circuit calculation in PowerFactory is able to simulate single faults as well as multiple faults of almost unlimited complexity. As short-circuit calculations can be used for a variety of purposes, PowerFactory supports different representations and calculation methods for the analysis of short-circuit currents. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 22. SHORT-CIRCUIT ANALYSIS This chapter presents the handling of the short-circuit calculation methods as implemented in PowerFactory. Further background on this topic can be found in Section 22.2.

22.2

Technical Background

Beside load flow calculations, short-circuit is one of the most frequently performed calculations when dealing with electrical networks. It is used both in system planning and system operation. Typical application examples of short-circuit analysis in system planning include: • Ensuring that the defined short-circuit capacity of equipment is not exceeded with system expansion and system strengthening. • Co-ordination of protective equipment (fuses, over-current and distance relays). • Dimensioning of earth grounding systems. • Verification of sufficient fault level capacities at load points (e.g. uneven loads such as arc furnaces, thyristor-driven variable speed drives or dispersed generation). • Verification of admissible thermal limits of cables and transmission lines. Example applications of short-circuit analysis in system operation include: • Ensuring that short-circuit limits are not exceeded with system reconfiguration. • Determining protective relay settings as well as fuse sizing. • Calculation of fault location for protective relays, which store fault disturbance recordings. • Analysis of system faults, e.g. misoperation of protection equipment. • Analysis of possible mutual interference of parallel lines during system faults. AC short circuit calculation quantities available in PowerFactory are shown in Figure 22.2.1, also a graphical representation of the AC short-circuit current time function is illustrated in Figure 22.2.2. Note that the quantities relating to the IEC 61363 standard [9] and DC short-circuit quantities calculated in DC short circuit standards IEC 61660 and ANSI/IEEE 946 are not shown in Figure 22.2.1. Note: The current waveform for a DC short circuit calculation is dependent on the type of DC current source(s), for more information please refer to Section 22.2.5 and Section 22.2.6 and the relevant IEC and ANSI/IEEE standards.

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22.2. TECHNICAL BACKGROUND

Figure 22.2.1: Areas of Application of Short-Circuit Calculations

According to IEC 60909 [11] the definition of the currents and multiplication factors shown in Figure 22.2.1 are as follows: • 𝐼𝑘𝑘𝑠 initial symmetrical short-circuit current (RMS), • 𝑖𝑝 peak short-circuit current (instantaneous value), • 𝐼𝑏 symmetrical short-circuit breaking current (RMS), • 𝐼𝑡ℎ thermal equivalent short-circuit current (RMS), • 𝜅 factor for the calculation of the peak short-circuit current, • 𝜇 factor for the calculation of the symmetrical short-circuit breaking current, • 𝑚 factor for the heat effect of the d.c. component, • 𝑛 factor for the heat effect of the a.c. component, besides the above currents, the Complete Method introduces the following current definition: • 𝑖𝑏 peak short-circuit breaking current (instantaneous value).

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Figure 22.2.2: Short-Circuit Current Time Function

The fundamental difference between the assumptions used by the calculation methods is that for system planning studies the system operating conditions are not yet known, and therefore estimations are necessary. To this end, the IEC (and VDE) methods which use an equivalent voltage source at the fault location have become generally accepted in countries using IEC based standards. For AC fault calculation, the IEC 60909 [11] (and VDE 0102) methods work independently of the load flow (operating point) of a system. The methods are based on the nominal and/or calculated dimensions of the operating point of a system and uses correction factors for voltages and impedances, to give conservative results. For the calculation of minimum and maximum short-circuit currents, different correction factors are applied. However, it should be mentioned that both IEC 60909 and VDE 0102 do not deal with single phase elements (except single phase elements in the neutral conductor). Another very similar method for AC fault calculation is the ANSI method, predominately used in North America but accepted in other countries as well. The ANSI method is based on the IEEE Standards C37.010 [1] which is for equipment applied in medium and high voltage systems (greater than 1000 Volts) and C37.13 [4] which is for power circuit breakers in low voltage systems (less than 1000 Volts). Other short circuit calculation methods available in PowerFactory include: • IEC 61363 [9]: Calculation of short-circuit currents on marine or offshore electrical systems such as ships. • IEC 61660 [8]: IEC standard for the calculation of short-circuit currents in DC auxiliary systems in power plants and substations. • ANSI/IEEE 946 [5]: ANSI/IEEE standard for the calculation of short-circuit currents in DC auxiliary systems in power plants and substations. For AC and DC short-circuit calculations in a system operation environment, the exact network operating conditions are well-known. If the accuracy of the calculation according to approximation methods such as IEC 60909 [11] is insufficient - or to verify the results of these methods - the superposition method can be used. The superposition method calculates the expected short-circuit currents in the network based on the existing network operating condition. If the system models are correct, the results from this method are always more exact than the results of the approximation method (such as IEC 60909). Often the system analyst must, however, ensure that the most unfavourable conditions are considered with respect to the sizing of plant. This may require extensive studies when using a superposition calculation method.

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22.2.1

The IEC 60909/VDE 0102 Method

The IEC 60909/VDE 0102 [11] method uses an equivalent voltage source at the faulted bus and is a simplification of the superposition method (Complete Method). It is illustrated in Figure 22.2.3. The goal of this method is to accomplish a close-to-reality short-circuit calculation without the need for the preceding load-flow calculation and the associated definition of actual operating conditions. Figure 22.2.3 illustrates how the equivalent voltage source method can be derived from the superposition method. The main simplifications are as follows: • Nominal conditions are assumed for the whole network, i.e. 𝑈 𝑖 = 𝑈 𝑛, 𝑖 • Load currents are neglected, i.e. 𝐼𝑂𝑝 = 0. • A simplified simulation network is used, i.e. loads are not considered in the positive and negative sequence network. • To ensure that the results are conservatively estimated, a correction factor, c, is applied to the voltage at the faulted busbar. This factor differs for the calculation of the maximum and the minimum short-circuit currents of a network. The short-circuit calculation based on these simplifications may be insufficient for some practical applications. Therefore, additional impedance correction factors are applied to the physical impedances of the network elements. This method is described in detail in the following section. Please note in addition that both IEC 60909 [11] and VDE 0102 do not deal with single phase elements (expect single phase elements in the neutral conductor).

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Figure 22.2.3: Illustration of the IEC 60909/VDE 0102(shcgrafiec.gif) Method

As illustrated in Figure 22.2.1, IEC 60909 requires the calculation of the initial symmetrical short circuit current in order to derive the rest of the physical quantities, each of which is a function of the following: • R/X ratio, • Machine characteristics • Synchronous generator type of excitation system, • Contact parting time, • Type of network (if it’s radial or meshed), • Determination if the contribution is “near to" or “far from" the short-circuit location, Regarding the type of network, IEC 60909 describes three methods for the calculation of (peak shortcircuit current) in meshed networks which are defined as follows: Method A: Uniform Ratio R/X The 𝜅 factor is determined based on the smallest ratio of R/X of all the branches contributing to the short-circuit current. Method B: Ratio R/X at the Short-Circuit Location For this method the 𝜅 factor is multiplied by 1.5 to cover inaccuracies caused by using the ratio R/X from a network reduction with complex impedances. 452

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22.2. TECHNICAL BACKGROUND Method C: Equivalent Frequency An equivalent impedance 𝑍𝑐 of the system as seen from the short-circuit location is calculated assuming a frequency 𝑓𝑐 = 20𝐻𝑧 (for a nominal frequency 𝑓𝑐 = 50𝐻𝑧) or 𝑓𝑐 = 24𝐻𝑧 (for a nominal frequency 𝑓𝑐 = 60𝐻𝑧). This is the recommended Method in meshed networks. Note: In PowerFactory methods B and C are available to the user. Method C is the one recommended in meshed networks. For more information please refer to Section 22.4.4

IEC Impedance Correction Factors The IEC 60909 method uses only the rated parameters of network elements. This is advantageous in that only little information is necessary to perform a short-circuit calculation. However, considering that, for example, the short-circuit contribution of a synchronous generator depends heavily on the excitation voltage and on the unit transformer tap changer position, the worst-case value of this impedance is considered by applying a correction factor (< 1). This idea is illustrated in Figure 22.2.4. The correction factor c should be determined so that 𝐼𝑘′′ = ′′ 𝐼𝑘,𝐼𝐸𝐶 . The IEC 60909 standard defines an equation for the correction factor for each element type.

Figure 22.2.4: Principle of Impedance Correction (IEC/VDE Method)

As the IEC 60909 standard includes a worst-case estimation for minimum and maximum short-circuit currents, some PowerFactory elements require additional data. These elements are: Lines In their type, the maximum admissible conductor temperature (for minimum short-circuit currents) must be stated (Figure 22.2.5). Line capacitances are not considered in the positive/negative sequence systems, but must be used in the zero-sequence system.

Figure 22.2.5: Maximum End Temperature Definition in the Line Type (TypLne)

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CHAPTER 22. SHORT-CIRCUIT ANALYSIS Transformers Require a flag indicating whether they are unit or network transformers as shown in Figure 22.2.6. Network transformers may be assigned additional information about operational limits which are used for a more precise calculation of the impedance correction factor. Unit transformers are treated differently depending on whether they have an on-load or a no-load tap changer (Figure 22.2.7).

Figure 22.2.6: Unit Transformer Definition in the Transformer Element (ElmTr2)

Figure 22.2.7: On-Load Tap Changer Definition in the Transformer Type (TypTr2)

Synchronous Machines Subtransient impedances are used. Additionally, information regarding the voltage range must be given as seen in Figure 22.2.8

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Figure 22.2.8: Voltage Range Definition in the Synchronous Machine Element (ElmSym)

Asynchronous Machines The ratio of starting current to rated current is used to determine the shortcircuit impedance (Figure 22.2.9)

Figure 22.2.9: Locked Rotor Current Definition in the Asynchronous Machine Type (ElmAsymo)

Please refer to the IEC 60909 standard to find detailed information regarding specific equipment models and correction factors for each element.

22.2.2

The ANSI Method

ANSI provides the procedures for calculating short-circuit currents in the following standards: • ANSI/IEEE Standard C37.010 [1], IEEE Application Guide for AC High-Voltage Circuit Breakers Rated on a Symmetrical Current Basis. • ANSI/IEEE Standard C37.13 [4] , IEEE Standard for Low-Voltage AC Power Circuit Breakers Used in Enclosures. • ANSI/IEEE Standard 141 [6], IEEE Recommended Practice for Electric Power Distribution of Industrial Plants (IEEE Red Book). • ANSI/IEEE Standard C37.5 [2], IEEE Application Guide for AC High-Voltage Circuit Breakers Rated on a Total Current Basis. (Standard withdrawn). DIgSILENT PowerFactory 15, User Manual

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CHAPTER 22. SHORT-CIRCUIT ANALYSIS ANSI C37.010 details the procedure for equipment applied in medium and high voltage systems considering a classification of the generators as either “local" or “remote" depending on the location of the fault, as well as taking into account motor contribution. The procedure also covers first cycle and interrupting time currents, with emphasis on interrupting time currents. ANSI C37.13 details the procedure for power circuit breakers applied in low voltage systems (less than 1000 Volts), while mainly focusing on first-cycle currents, impedance of motors and the fault point X/R ratio. Typically, fuses and low voltage circuit breakers begin to interrupt in the first half cycle so no special treatment for interruptive current is given. It could be the case however, that nevertheless the equipment test include a dc component specification. Due to the differences in the high and low voltage standards, it would be understandable to say that two first-cycle calculations are required. The first calculation would be for high voltage busbars and a second calculation would be for low-voltage busbars. In IEEE/ANSI Standard 141-1993 [6] (Red Book) a procedure for the combination of first cycle network is detailed. There is stated that in order to simplify comprehensive industrial system calculations, a single combination first-cycle network is recommended to replace the two different networks (high/mediumvoltage and low voltage). This resulting combined network is then based on the interpretation of the ANSI C37.010 [1], ANSI C37.13 [4] and ANSI C37.5 [2] there given. Total and Symmetrical Current Rating Basis of Circuit Breakers and Fuses according to ANSI Standards Depending on the circuit breaker year of construction different ratings are specified. High-voltage circuit breakers designed before 1964 were rated on “Total" current rating while now a day’s high-voltage circuit breakers are rated on a “Symmetrical" current basis. The difference between these two definitions is on how the asymmetry is taken into account. While a “Total" current basis takes into account the ac and dc decay, “Symmetrical" current basis takes into account only the ac decay. To explain further these definitions please refer to Figure 22.2.10.

Figure 22.2.10: Asymmetrical Short-Circuit Current

The DC component “DC" is calculated according to the following equation:

𝐷𝐶 =

𝑃1 − 𝑃2 2

(22.1)

The RMS value of the ac component (RMS) is then calculated as:

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𝑃1 + 𝑃2 2.828

(22.2)

𝐷𝐶 2 + 𝑅𝑀 𝑆 2

(22.3)

𝑅𝑀 𝑆 = The total interrupting current in RMS is then: 𝑇 𝑜𝑡 =

√︀

From the above, Equation (22.2) corresponds to the “Symmetrical" current calculation and Equation (22.3) to the “Total" current calculation. Some of the main ANSI guidelines for the calculation of shortcircuit currents are the following: • The pre-fault busbar voltage is assumed to be nominal (1.0 p.u.). • The fault point X/R ratio is calculated based on a separate resistance network reduction which is latter used to calculate the peak and total asymmetrical fault current. • Depending on the location of the fault, the generator currents being fed to the short circuit are classified as “local" or “remote". A remote source is treated as having only a dc decay, while a local source is treated as having a dc and ac decay. Depending on this classification, corresponding curves are used in order to obtain the multiplication factors. According to ANSI standard, the following short-circuit currents are calculated: • 𝐼𝑠𝑦𝑚𝑚 symmetrical momentary (first cycle) short-circuit current (RMS), • 𝐼𝑠𝑦𝑚𝑖 symmetrical interrupting short-circuit current (RMS), • 𝐼16𝑎𝑠𝑦𝑚𝑚 asymmetrical momentary (Close and Latch - Duty) short-circuit current (RMS). Obtained by applying a 1.6 factor to 𝐼𝑠𝑦𝑚𝑚 • 𝐼27𝑝𝑒𝑎𝑘𝑚 peak short-circuit current (instantaneous value). Obtained by applying a 2.7 factor to 𝐼𝑠𝑦𝑚𝑚 , • 𝐼𝑎𝑠𝑦𝑚𝑚 asymmetrical momentary (Close and Latch - Duty) short-circuit current(RMS). Obtained by applying a factor to 𝐼𝑠𝑦𝑚𝑚 according to the calculated X/R ratio, • 𝐼𝑝𝑒𝑎𝑘𝑚 peak short-circuit current (instantaneous value). Obtained by applying a factor to 𝐼𝑠𝑦𝑚𝑚 , according to the calculated X/R ratio.

22.2.3

The Complete Method

The complete method (sometimes also known as the superposition method) is, in terms of system modelling, an accurate calculation method. The fault currents of the short-circuit are determined by overlaying a healthy load-flow condition before short-circuit inception with a condition where all voltage supplies are set to zero and the negative operating voltage is connected at the fault location. The procedure is shown in Figure 22.2.11. The initial point is the operating condition of the system before short-circuit inception (see Figure 22.2.11a). This condition represents the excitation conditions of the generators, the tap positions of regulated transformers and the breaker/switching status reflecting the operational variation. From these pre-fault conditions the pre-fault voltage of the faulted busbar can be calculated. For the pure fault condition the system condition is calculated for the situation where, the negative pre-fault busbar voltage for the faulted bus is connected at the fault location and all other sources/generators are set to zero (see Figure 22.2.11b). Since network impedances are assumed to be linear, the system condition after fault inception can be determined by overlaying (complex adding) both the pre-fault and pure fault conditions (see Figure 22.2.11c). DIgSILENT PowerFactory 15, User Manual

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Figure 22.2.11: Illustration of the Complete Method

The Complete Methodfor calculating short-circuits has been improved in PowerFactory Version 14 as described below. Additionally, the quantities described below are shown in Figure 22.2.1. • A more precise Peak Short-Circuit Current 𝑖𝑝 is calculated based on the accurate subtransient short-circuit current (which is calculated using the complete method) and the R/X ratio (which is based on the IEC 60909 standard[11]); • The Short-Circuit Breaking Current 𝐼𝑏 (RMS value) is calculated based on the subtransient shortcircuit current and the transient short-circuit current (both of which are calculated by the complete method); • The Peak Short-Circuit Breaking Current 𝑖𝑏 is calculated from the RMS short-circuit breaking current 𝐼𝑏 and the decaying d.c. component; • The Thermal Equivalent Short-Circuit Current 𝐼𝑡ℎ is calculated based on the IEC standard, using the m and n factors (see Figure 22.2.1). The n-factor calculation uses the transient current instead of the steady-state current; • Additionally, loads can have a contribution to the short-circuit current, which can be defined in the load element (Fault Contribution section of Complete Short-Circuit tab).

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22.2.4

The IEC 61363 Method

The IEC 61363 standard [9]describes procedures for calculating short-circuit currents in three-phase AC radial electrical installations on ships and on mobile and fixed offshore units. The IEC 61363 standard [9]defines only calculation methods for three phase (to earth) short circuits. Typically marine/offshore electrical systems are operated with the neutral point isolated from the hull or connected to it through an impedance. In such systems, the highest value of short-circuit current would correspond to a three phase short circuit. If the neutral point is directly connected to the hull, then the line-to-line, or line-to shipŠs hull short-circuit may produce a higher current. Two basic system calculation approaches can be taken, “time dependent" and “non-time dependent". According to the IEC 61363 standard [9], PowerFactory calculates an equivalent machine that feeds directly into the short circuit location. This machine summarizes all “active" and “non-active" components of the grid. The short-circuit procedure in IEC 61363 [9] calculate the upper envelope (amplitude) of the maximum value of the time dependent short-circuit (see Figure 22.2.2). The envelope is calculated using particular machine characteristics parameters obtainable from equipment manufacturers using recognized testing methods, and applying the following assumptions: • All system capacitances are neglected. • At the start of the short-circuit, the instantaneous value of voltage in one phase at the fault point is zero. • During the short-circuit, there is no change in the short-circuit current path. • The short-circuit arc impedance is neglected. • Transformers are set at the main tap position. • The short-circuit occurs simultaneously in all phases. • For generator connected in parallel, all generators share their active and reactive load proportionally at the start of or during the short-circuit. • During each discrete time interval, all circuits components react linearly. The exact guidelines on how this is achieved is specified in the standard. Because the standard considers specific system components and models (“active" and “non-active") some of the models that can be used in PowerFactory will have no description according to the standard (such as External Grids, Voltage Sources, Static Generators, etc.). How these elements are considered and transformed to a replacement equivalent machine is described in the corresponding Technical Reference (appendix C). According to this method, the following short-circuit values are calculated: • 𝐼”𝑘 initial symmetrical short-circuit current, • upper envelope of short-circuit current 𝐼𝑘 (𝑡) , • 𝑖𝑑𝑐 (𝑡) decaying (aperiodic) component of short-circuit current, • 𝑖𝑝 peak short-circuit current, • 𝐼𝑘 steady-state short-circuit current.

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CHAPTER 22. SHORT-CIRCUIT ANALYSIS The calculating formulae and methods described produce sufficiently accurate results to calculate the short-circuit current during the first 100 ms of a fault condition. It is assumed in the standard that during that short time the control of the generators has no significant influence on the short circuit values. The method can be used also to calculate the short-circuit current for periods longer than 100 ms when calculating on a bus system to which the generators are directly connected. For time periods beyond 100 ms the controlling effects of the system voltage regulators may be predominant. Calculations including the voltage regulator effects are not considered in this standard. In PowerFactory besides the standard IEC 61363 [9] method, an EMT simulation method is available which considers also the first 100 ms of a three phase short-circuit.

22.2.5

The IEC 61660 (DC) Method

The IEC 61660 standard [8] describes a detailed method for calculating short-circuit currents in DC auxiliary systems in power plants and substations. The standard details considerations for voltages up to 250 VDC. Such systems can be equipped with the following equipment, acting as short-circuit current sources: • rectifiers in three-phase AC bridge connection. • stationary lead-acid batteries. • smoothing capacitors. • DC motors with independent excitation. The IEC 61660 standard [8] defines equations and equivalent circuits which approximate the timedependent fault contribution of different DC current sources. The standard also defines correction factors and approximation methods to determine the total DC short circuit current at the point of fault. A graphical representation of the DC short-circuit current time function of different DC sources is illustrated in Figure 22.2.12.

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Figure 22.2.12: DC Short-Circuit Current Time Function of different sources

In accordance with standard IEC 61660 [8], PowerFactory calculates the total DC fault current by considering all of the DC current sources feeding in to the short circuit location. How different elements are considered and modelled is described in the corresponding Technical Reference (appendix C). Figure 22.2.13 shows the IEC 61660 standard approximation function which covers the different short circuit current variations. The equations which describe the function are detailed in IEC 61660.

Figure 22.2.13: IEC 61660 standard DC short-circuit approximation function DIgSILENT PowerFactory 15, User Manual

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CHAPTER 22. SHORT-CIRCUIT ANALYSIS According to the IEC 61660 method, the following short-circuit values are calculated: • 𝑖𝑝 peak short-circuit current • 𝐼𝑘 quasi steady-state short-circuit current • 𝑡𝑝 time to peak • 𝜏𝑟 rise-time constant • 𝜏𝑑 decay-time constant • 𝑇𝑘 fault clearing time

22.2.6

The ANSI/IEEE 946 (DC) Method

The IEEE 946 standard [5] describes a recommended practice for the design of DC auxiliary power systems for nuclear and non-nuclear power stations. The standard provides guidance on the selection of equipment including ratings, interconnections, instrumentation, control and protection. The IEEE 946 standard [5], is closely linked to General Electric’s Industrial Power Systems Data Book [16]. The IEEE 946 standard includes examples for the calculation of short-circuit contribution from a battery and a battery charger, whilst the GE Industrial Power Systems Data Book includes a methodology for calculation of the DC fault contribution of Batteries, DC machines and Rectifiers. The DC short circuit calculation in PowerFactory is in accordance with the approach taken in the IEEE standard and the GE Industrial Power Systems Data Book. How different elements are specifically considered and modelled is described in the corresponding Technical Reference (appendix C). According to the IEEE 946 method, the following short-circuit values are calculated: • 𝑖𝑝 peak short-circuit current • 𝐼𝑘 quasi steady-state short-circuit current • 𝑇𝑛 network time constant • 𝑅𝑅 rate of rise of short-circuit current

22.3

Executing Short-Circuit Calculations

There are different methods of initiating the short-circuit calculation command ComShc in PowerFactory , which may result in a different configuration of the command. These methods are described in Sections 22.3.1 and 22.3.2.

22.3.1

Toolbar/Main Menu Execution

The short-circuit command may be executed from the toolbar or main menu in PowerFactory as follows: • By pressing the

icon on the main toolbar; or

• By selecting the Calculation → Short-Circuit ... option from the main menu.

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22.3. EXECUTING SHORT-CIRCUIT CALCULATIONS If the user is performing the short-circuit for the first time (by using one of the above options), the shortcircuit command will be configured in a certain manner by default; that is the command will be set by default to execute a short-circuit calculation on all busbars/terminals in the network. If a short-circuit calculation has been already performed (the command exists in the study case) the settings displayed by the short-circuit command will be according to the most recent short-circuit calculation. As an example, if the user performs a short-circuit calculation according to ANSI for only one busbar in the system, the next time the user executes again the short-circuit, the command will have the most recent settings, that is, in this case according to ANSI and for the specified busbar.

22.3.2

Context-Sensitive Menu Execution

The short-circuit command may be executed from the context-sensitive menu in PowerFactory by selecting an element(s) in the single-line diagram, right-clicking and selecting one of the following options: • Calculate... Short-Circuit: performs a short-circuit calculation for each element selected by the user. It should be noted that the short-circuit calculation for each element is carried out completely independently of the short-circuit calculation for each other element. For this calculation, only the following combinations of elements may be selected: – Single or multiple terminals/busbars; or – A single line; or – A single branch. If several terminals/busbars are selected for analysis, the results of each individual short-circuit calculation will be displayed together on the single-line graphic. • Calculate... Multiple Faults: performs a short-circuit calculation according to the complete method, ´ for the SsimultaneousŠ short-circuit of all elements selected by the user. Any combination of busbars, terminals, lines and branches can be selected for this calculation. Additionally, switch/circuit breaker open/close operations can also be included in the calculation. When this calculation is selected, the option Multiple Faults in the ComShc dialogue will be automatically ticked.

22.3.3

Faults on Busbars/Terminals

The short-circuit command should first be called using one of the methods described in Sections 22.3.1 and 22.3.2. The simplest way to calculate several busbar/terminal short-circuits individually and to then combine the results into one diagram is to select the option All Busbars (or alternatively, Busbars and Junction/Internal Nodes) in the Fault Location section of the Short-Circuit Calculation ComShc dialogue, as displayed in Figure 22.3.1. Note that to access this option, Multiple Faults in the dialogue must be un-selected.

Figure 22.3.1: Short-Circuit Calculation Command ComShc Dialogue: Faults at All Busbars

If the user would instead like to select from the single-line diagram a single busbar/terminal, or multiselect several busbars/terminals for calculation, the dialogue will be configured as follows: • When only a single busbar/terminal is selected, and Calculate → Short-Circuit is chosen from the context-sensitive menu, the Fault Location reference (bottom of dialogue) is set to the selected element. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 22. SHORT-CIRCUIT ANALYSIS • When two or more busbars/terminals are selected and Calculate → Short-Circuit is chosen from the context-sensitive menu, the Fault Location reference (bottom of dialogue) is set to a so-called “Selection Set" SetSelect object, which contains a list of references to the selected busbars/terminals. In either case, various options for the calculation can be modified. Please refer to Section 22.4 for a detailed description of the options available. It should be noted that selecting or deselecting the option Multiple Faults may change the selection of fault locations and may therefore lead to a calculation for locations other than the busbars/terminals selected in the single line graphic. After pressing the Execute button, the calculation is executed and, if successful, the results are displayed in the single line graphic. In addition, a result report is available and may be printed out. Once a selection of fault locations is made and the short-circuit calculation is performed, it is simple to execute further calculations based on the same selection of elements. This can be done by the following alternative means of executing the short-circuit calculation command: • By pressing the

icon on the main toolbar; or

• By selecting the Calculation → Short-Circuit ... option from the main menu. The short-circuit setup dialogue then shows the previously selected busbars/terminals in the Fault Location section under User Selection.

22.3.4

Faults on Lines and Branches

It is not only possible to calculate short-circuits on busbars and terminals, but also on lines and branches. It should be noted, however, that only a single line or a single branch can be selected at a time, for each short-circuit calculation. It is not possible to select multiple lines and/or branches for calculation. To calculate a short-circuit on one of these types of elements, proceed as follows: • From the single-line diagram, select a single line or a single branch where the fault should be calculated. • Right-click on the element and select Calculation → Short-Circuit .... The short-circuit command ComShc dialogue opens and the user can then define the location of the fault relative to the elementŠs length (see Figure 22.3.2), including which terminal the fault distance should be calculated from. It should be noted that the Short-Circuit at Branch/Line section of this tab is only available when a line or branch has been selected for calculation. • Clicking the button located in the Short-Circuit at Branch/Line section of the tab will enable the user to select whether the fault location is defined as a percentage or as an absolute value.

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Figure 22.3.2: Configuration of Line/Branch Faults in ComShc Dialogue

When a fault on a line/branch is calculated, a box containing the calculation results is displayed next to the selected element.

22.3.5

Multiple Faults Calculation

Multiple faults involve the simultaneous occurrence of more than one fault condition in a network. This option is only available for the complete method. To calculate simultaneous multiple faults, proceed as follows: • Select two or more elements (i.e. busbars/terminals, lines, ...) and right-click. • Select the option Calculate → Multiple Faults. The Short-Circuits dialogue pops up, displaying the short-circuit event list. A 3-phase fault is assumed by default at all locations in the event list. Click OK. The Short-Circuit command dialogue then pops up. In this dialogue, the Multiple Faults option is ticked in combination with the complete short-circuit method. • Finally, press Execute to start the calculation. In cases where the event list has to be adapted to reflect the intended fault conditions (that is, not necessarily the calculation of 3-phase faults), please proceed as follows: • Open the short-circuit events object using one of the following methods: – In the Fault Location section of the short-circuit ComShc dialogue, press the Show button (see Figure 22.3.3; or – Press the ton); or

icon located on the main tool bar (just besides the short-circuit command but-

– In a Data Manager window, open the IntEvtshc object from the current study case, also denoted by the icon.

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Figure 22.3.3: Accessing the Short-Circuit Events List • A window opens up which shows the list of events (that is short-circuits at the selected locations). When double-clicking on one entry in this list (double-clicking on the entire row), a window with a description of the event is opened. • The short-circuit event settings can now be modified. The list of fault locations consists of a “ShortCircuit Event List"(IntEvtshc) object, which holds one or more short-circuit events (EvtShc). Each of these events has a reference to a fault location (a busbar/terminal, line, etc.) and displays a short description of the fault type. An example is shown in Figure 22.3.4. • The user could add more fault locations to the “Short-Circuit Event List" (IntEvtshc) object by right clicking on addition elements in the single line diagram Add to.. → Multiple Faults.

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Figure 22.3.4: A Short-Circuit Event (EvtShc) Note: To re-use the event list (IntEvtshc) later, this object can be copied to a user-defined folder in the Data Manager. This will prevent it from being modified during future calculations. When repeating the calculation with the same configuration, the reference in Calculate → Multiple Faults can be set to this object. The other option would be to copy the events to the Fault Cases folder located ˇ in the TOperational Library/FaultsTˇ folder of the project. The user would then need to press the From Library button (22.3.3).

22.4

Short-Circuit Calculation Options

The following sections describe the options available in PowerFactory ’s short-circuit calculation command. Some of these options are dependent upon the selected calculation method, therefore separate sections dedicated to each method are presented.

22.4.1

Basic Options (All Methods)

The options presented in this section are common to all implemented calculation methods and are used to define the general settings of the short-circuit calculation. The specific options for each method are presented below in separate sections.

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Figure 22.4.1: IEC Calculation - Basic Options

An example of the short-circuit command dialogue is shown in Figure 22.4.1 (IEC calculation in this case). The sections of the dialogue which are common to all calculation methods are: Method PowerFactory provides the following calculation methods for short-circuit calculation: • VDE 0102 [11] (the German VDE standard); • IEC 60909 [11] (the International IEC standard); • ANSI (the American ANSI/IEEE C37 standard); • complete (superposition method which considers the pre-fault load-flow results (see Section 22.2.3); • IEC 61363 [9]; • IEC 61660 (DC) [8]; (the International IEC standard for DC short circuit calculation) • ANSI/IEEE 946 (DC) [5] (the ANSI/IEEE standard for DC short circuit calculation). The specific options for each of these methods are available on the Advanced Options page of the short-circuit command ComShc dialogue. Fault Type The following fault types are available: • 3-Phase Short-Circuit • 2-Phase Short-Circuit 468

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22.4. SHORT-CIRCUIT CALCULATION OPTIONS • Single Phase to Ground • 2-Phase to Ground • 1-Phase to Neutral • 1-Phase Neutral to Ground • 2-Phase to Neutral • 2-Phase Neutral to Ground • 3-Phase to Neutral • 3-Phase Neutral to Ground • 3-Phase Short-Circuit (unbalanced) The fault types with a neutral conductor should only be used for systems which are modelled using neutral conductors. Fault Impedance (Except for IEC 61363) The fault impedance corresponds to the reactance and the resistance of the fault itself (such as the impedance of the arc or of the shortening path). This can be defined by means of an enhanced model, where line to line (𝑋𝑓 (𝐿 − 𝐿), 𝑅𝑓 (𝐿 − 𝐿)) and line to earth 𝑋𝑓 (𝐿 − 𝐸), 𝑅𝑓 (𝐿 − 𝐸)) impedances are regarded (note: requires option Enhanced Fault Impedance to be enabled). If the option Enhanced Fault Impedance is not enabled, fault impedances are defined by their equivalent values, 𝑋𝑓 and 𝑅𝑓 . Figures 22.4.2 to 22.4.4 illustrate the differences between the enhanced and the simplified representation of fault impedances for the following fault types: (i) 3-phase short-circuits; (ii) 2-phase faults to ground; and (iii) 2-phase faults.

Figure 22.4.2: Fault Impedance Definition: 3-Phase Short-Circuit

Figure 22.4.3: Fault Impedance Definition: 2-Phase to Ground Fault

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Figure 22.4.4: Fault Impedance Definition: 2-Phase Fault

Show Output A textual report is automatically written to PowerFactory ’s output window when the Show OutputShow Output option of the dialogue is enabled. The command which generates this report is displayed in blue text next to the Command button . The user can click on this button to select which type of report will be printed out. Just below the Command button, blue text informs the user of the currently-selected report type. Fault Location The fault location selection options are: At User Selection: In this case a reference to a single terminal/ busbar/ line/ branch or to a selection of busbars/ terminals SetSelect, as explained in Sections 22.3.3 and 22.3.4must be given. At Busbars and Junctions/ Internal Nodes: For every terminal (ElmTerm) in the network, a short-circuit calculation is carried out, independently (one after the other). At All Busbars: For every terminal (ElmTerm) in the network whose Usage is set to Busbar, a short-circuit calculation is carried out, independently (one after the other). If the option Multiple Faults has been ticked when the Complete Method is being used, a reference to a set of fault objects (IntEvtshc), as explained in Section 22.3.5, must be set. This is done in the Fault Location section of the dialogue; using the Short Circuits reference. Note: Multiple faults will only be calculated for the Complete Method, when the option Multiple Faults is enabled. When this option is enabled, a short-circuit calculation is carried out for each individual fault location, simultaneously. When this option is disabled, cases where more than one fault location have been selected (i.e. several busbars/terminals), a sequence of short-circuit calculations is performed (i.e. each short-circuit calculation is carried out independently of each other shortcircuit calculation).

22.4.2

Verification (Except for IEC 61363, IEC 61660 and ANSI/IEEE 946)

When enabled (Verification Tab Page), the user can enter thresholds for peak, interrupting and thermal maximum loading. The Verification option will then write a loading report to the output window with all devices that have higher loadings than the defined max. values. This report shows the various maximum and calculated currents for rated devices. Rated devices include, for instance: • Lines which have a rated short-time current in their line type which is greater than zero; and • Breakers or coupling switches which have a type with a valid rated current. 470

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22.4. SHORT-CIRCUIT CALCULATION OPTIONS

22.4.3

Basic Options (IEC 60909/VDE 0102 Method)

The Basic Options page of the Short-Circuit Calculation dialogue is shown in the previous section in Figure 22.4.1. In general, please note that the calculation according to IEC 60909 [11] and VDE 0102 does not take into account line capacitances, parallel admittances (except those of the zero-sequence system) and non-rotating loads (e. g. ElmLod). Single phase elements are considered only if they are located in the neutral conductor. Published This option offers a sub-selection for the selected Method, where the version of the standard to be used can be selected according to the year in which it was issued. The most recent standard is 2001, however 1990 is still available for the verification of documented results. Calculate The drop-down list offers the choice between the minimal or maximal short-circuit current. If external grids are defined, the corresponding maximum or minimum value will be selected automatically. For example if in the short circuit command you select “Calculate" according to “Maximum Short Circuit currents", the maximum short circuit value from the external grid is considered for the calculation. The equivalent voltage source is based on the nominal system voltage and the voltage factor c. The voltage ˇ stated in factor c will depend on the voltage level and on the selection of the “Calculate according toE" the short-circuit command. Max. Voltage tolerance for LV systems In accordance with the IEC/VDE standard, this voltage tolerance is used to define the respective voltage correction factor, 𝑐. The voltage tolerance is not used when a user-defined correction factor is defined. Short-Circuit Duration The value for the Breaker Time is used to calculate the breaking current of a circuit breaker. The value for the Fault Clearing Time (Ith) is required for the equivalent thermal current. Note: The fields Method, Fault Type, Fault Impedance, Output and Fault Location are described in Section 22.4.1.

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22.4.4

Advanced Options (IEC 60909/VDE 0102 Method)

Figure 22.4.5: IEC calculation - Advanced Options

Generally, the Advanced Options page (shown in Figure 22.4.5) is used for settings to tune the various short-circuit calculation methods. Familiarization with the IEC/VDE standard before modifying these options is strongly recommended. Grid Identification The calculation of the factor kappa is different in the cases of meshed or radial feeding of the shortcircuit. Normally PowerFactory will automatically find the appropriate setting. The option Always meshed will force a meshed grid approach. c-Voltage Factor The standard defines the voltage factor c to be used for the different voltage levels. In special cases the user may want to define the correction factor. In this case, activate the box User-Defined, then a specific c-factor can be entered. Asynchronous Motors Whether the calculation considers the influence of asynchronous motors on short-circuit currents depends on this setting, which may be Always Considered, Automatic Neglection, or Confirmation of Neglection. Conductor Temperature When activating the User-Defined option, the initial (pre-fault) conductor temperature can be set manually. This will influence the calculated maximum temperature of the conductors, as caused by the short-circuit currents. Decaying Aperiodic Component Allows for the calculation of the DC current component, for which the decay time must be given. According to the IEC/IEC standard, methods 𝐵, 𝐶 and 𝐶 ′ can be selected. The following nomenclature is used:

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22.4. SHORT-CIRCUIT CALCULATION OPTIONS • 𝑇𝑏 ) Breaker Time (see Short-Circuit command) • 𝑓 − 𝑛) Nominal frequency • 𝐼𝑘 ”) Initial short-circuit current Method B: Uses the complex calculated equivalent impedance of the network with a security factor of 1.15: √ 𝑅 (22.4) 𝑖𝐷𝐶 = 2 · 𝐼𝑘” · 𝑒−𝜔·𝑇𝑏 · 𝑥 Method C Uses the R/X ratio calculated with the equivalent frequency method. The equivalent frequency is dependent on the breaking time (see Table 22.4.1). This method is recommended for maximum accuracy.

𝐼𝐷𝐶 =

√

𝑅

2 · 𝐼”𝑘 · 𝑒

−𝜔·𝑇𝑏 · 𝑥 𝑓

(22.5)

𝑓

𝑅𝑓 𝑅𝑐 𝑓𝑐 = · 𝑋𝑓 𝑋𝑐 𝑓𝑛𝑜𝑚

(22.6)

The ratio Rc/Xc is the equivalent impedance calculated at the frequency given by:

𝑓𝑐 =

𝑓𝑐 · 𝑓𝑛𝑜𝑚 𝑓𝑛𝑜𝑚

(22.7)

Method C’ Uses the R/X ratio as for the peak short-circuit current, thus selecting the ratio fc/fn = 0.4. This option speeds up the calculation, as no additional equivalent impedance needs to be calculated. Peak Short-Circuit Current (Meshed network) In accordance with the IEC/VDE standard, the following methods for calculating kappa can be selected: Method B’ Uses the ratio R/X at the short-circuit location. Method C(1) Uses the ratio R/X calculated at a virtual frequency of 40% of nominal frequency (20 Hz for fn = 50 Hz, or 24 Hz for fn=60 Hz), based on the short-circuit impedance in the positive sequence system. Method (012) Like C(1), but uses the correct short-circuit impedance based on the positive-, negative- and zero-sequence system. Calculate Ik The steady-state short-circuit currents can be calculated using different means to consider asynchronous machines: Without Motors Will disconnect all asynchronous motors before calculating the current 𝐼𝑘 . DIgSILENTMethod Considers all asynchronous motors according to their breaker current. The breaker opens after the maximum possible time. 𝑓𝑛 * 𝑇𝑏 𝑓𝑐 /𝑓𝑛

1, ’Maximum exceeded: yt=yt>1’) The ’(’ and ’)’ braces exclude the minimum or maximum value from the interval; the ’[’ and ’]’ braces include them. Examples: limits(x)=[min,max] limits(x)=(min,max] limits(x)=(,max] ! limits(x)=(min,) !

! min = 0). k corresponds to the number of network regions (sets of topologically connected components) which are disconnected during a fault, by the switching actions performed. It should be noted that the switching actions which are considered depend on the post contingency time used by the update (this time differs between single- and multiple time phase analyses).

Figure 29.6.1: Fault Type Field in the Contingency Case (ComOutage) Dialogue

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29.6. CREATING CONTINGENCY CASES USING FAULT CASES AND GROUPS Note: In PowerFactory an interrupted component is a network primary element that is energized before a fault and de-energized afterwards. A component is considered to be energized if it is topologically connected to a network reference bus. A region is defined as a set of topologically connected components. Like components, regions can have energized, de-energized and interrupted states, depending on their connection to a network reference bus.

Contingency cases can be created from fault cases/groups, which reside in the Operational Library, by pressing the Add Cases/Groups button in the contingency analysis command (see Section 29.4.1 (Basic Options) and Figure 29.4.2). In the case of creating contingencies from fault group(s), a contingency case will be generated for each fault case referred to in the selected fault group(s). Note: The ’topological search’ algorithm used by the program to set contingency cases from fault cases requires the explicit definition of at least one reference bus in the analyzed system. A bus is explicitly set as a reference if it has connected to it either a synchronous generator (ElmSym), or an external network (ElmExtnet) with the option ’Reference Machine’ enabled (available on the element’s ’Load Flow’ tab).

29.6.1

Browsing Fault Cases and Fault Groups

There are two types of subfolder inside the Faults folder in the Operational Library : Fault Cases and Fault Groups.

Figure 29.6.2: Contents of the Faults folder in the Operational Library

In order to make a new folder of either of these types, left-click on the Faults folder icon ( ) and then press the New Object button ( ) on the Data Manager toolbar. In the drop-down list, select whether a new Fault Cases or Fault Groups folder should be created. The Fault Cases folder holds every contingency (n-1, n-2, or simultaneous) defined for the system, as described in Section 29.6.2 (Defining a Fault Case). Alternatively, several fault cases can be selected and stored in a Fault Group, as described in Section 29.6.3 (Defining a Fault Group).

29.6.2

Defining a Fault Case

To define a fault case for an element in the grid, select it in the single-line diagram. Then right-click and choose one of: Define. . . → Fault Case→ Single Fault Case or Define. . . → Fault Case→ Multiple Fault DIgSILENT PowerFactory 15, User Manual

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CHAPTER 29. CONTINGENCY ANALYSIS Cases, n-1 (or Multiple Fault Cases, n-2) or Define. . . → Fault Case→ Mutually Coupled Lines/Cables, n-k. If Multiple Fault Cases, n-2 is selected, fault cases will be created for the simultaneous outage of every unique combination of two elements in the selection. If the user selects Single Fault Case, a fault case will be created for the simultaneous outage of all elements in the selection. If Mutually Coupled Lines/Cables, n-k is selected, then fault cases will be created for the simultaneous outage of each coupled line in the selection. Alternatively, a filter can be used. This can be done (for example) with the help of the Edit Relevant Objects for Calculation button ( ), to list all elements for which outages are to be defined. These elements can then be highlighted and the user can then right-click on the highlighted selection and choose (for example) Define. . . → Fault Case. . . . The Simulation Events/Fault dialogue opens, as shown in Figure 29.6.3, where the user can enter the desired name of the fault case in the Name field. On the Advanced tab of the Basic Data page of the same dialogue, the user can create the corresponding switch events, by clicking on the Create Switch Events button.

Figure 29.6.3: Creation of Fault Case (IntEvt)

Fault cases can also be defined by the Contingency Definition command, as explained in Section 29.7 (Creating Contingency Cases Using the Contingency Definition Command). For further background on fault cases, please refer to Chapter 12: Project Library, Section 12.3.3 (Fault Cases and Fault Groups).

29.6.3

Defining a Fault Group

To define a fault group, left-click on the Fault Groups folder. Then click on the New Object button ( ). A Fault Group dialogue pops up as shown in Figure 29.6.4. In this dialogue the user can specify the name of the fault group in the Name field, and add fault cases to this new group using the Add Cases button. Click the Cases button to view existing cases (if any) in the fault group.

Figure 29.6.4: Creation of Fault Group (IntFaultgrp)

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29.7. CREATING CONTINGENCY CASES USING THE CONTINGENCY DEFINITION COMMAND Note: When a fault group is defined and fault cases are added to it, a reference is created to each of these fault cases. The fault case itself resides in the Fault Cases subfolder. This means that if an item in the fault group is deleted, only the reference to the fault case is deleted. The fault case itself is not deleted from the Fault Cases subfolder.

29.7

Creating Contingency Cases Using the Contingency Definition Command

The Contingency Definition command (ComNmink ) is used to automatically generate contingency cases based on selected components. It is accessible via the Contingency Analysis toolbar ( ) but using the button. The Contingency Definition command can be used to automatically generate contingency cases for either (i) a user-defined selection of elements; or (ii) pre-defined sets of elements. These two approaches are now described. To generate contingency cases for a user-defined selection of elements: • Select the components to be put on outage either by multi-selecting them in the single line graphic or the Data Manager. • Right click on the selection and choose Calculate → Contingency Analysis. . . from the context sensitive menu. This command will create a list with references to the selected objects inside the Contingency Definition command (ComNmink ). The command dialogue shown in Figure 29.7.1 will pop up. • Select the required outage level. • Select the Creation of Contingencies option according to how the contingencies should be handled (see explanation of options below) and click on Execute. To generate contingency cases for either the complete system or from pre-defined sets of elements: • Click on the

icon on the main toolbar to open the command;

• Select the option Whole System in the Create Cases for field; • Select the required pre-defined set of elements (for example transformers and lines); • Select the Creation of Contingencies option according to how the contingencies should be handled (see explanation of options below) and click on Execute.

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Figure 29.7.1: Contingency Definition Dialogue (option: Generate Contingencies for Analysis)

Once the Contingency Definition command is executed, it generates the corresponding contingency cases according to the options and elements selected. The Contingency Analysis command, which is automatically created inside the current active Study Case is then automatically opened. The created contingencies can be analyzed by executing this already-opened Contingency Analysis command. Note that when a new list of contingencies is created using the Contingency Definition command, the previous content of the contingency analysis command is overwritten. It is also possible to open the Contingency Definition command directly from the Contingency Analysis toolbar, without any previous selection, by clicking on the icon. In this case, contingencies for all elements within the network (selected according to their class, as described below), can be created. The Contingency Definition command offers the following options to generate contingency cases from the selected objects: Creation of Contingencies Generate Fault Cases for Library Generates fault cases which are stored in the Operational Library, in a folder named Faults. Alarm Generates contingencies which are stored in the contingency analysis command, and then opens the contingency analysis command (ComSimoutage) dialogue. Outage Level n-1 Creates single contingency cases for each of the selected components. n-2 Creates contingency cases for every unique combination of two selected components. n-k cases of mutually coupled lines/cables Creates contingency cases for every set of mutually coupled lines/cables. If for example, three lines are modelled as having a mutual coupling, by selecting this option a fault case is created considering the simultaneous outage of the three coupled lines. Lines/cables Contingency cases according to the selected outage level will be generated for all lines and cables 678

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29.8. COMPARING CONTINGENCY RESULTS (ElmLne objects) in the system. Transformers Contingency cases according to the selected outage level will be generated for all transformers (ElmTr2, ElmTr3 objects) in the system. Generators Contingency cases according to the selected outage level will be generated for all synchronous generators (ElmSym objects) in the system. Series Capacitors Contingency cases according to the selected outage level will be generated for all series capacitors (ElmScap objects) in the system. Series Reactors Contingency cases according to the selected outage level will be generated for all series reactors (ElmSind objects) in the system. The selection of elements to outage in the Contingency Definition command can also be created by the use of DPL scripts. Please refer to the ComNmink methods in the appendix DPL Reference. Note: It is important to note the difference between contingency cases created from fault cases and contingency cases created with the Contingency Definition command. In the former, the cases are regarded as the outage of certain network components as a consequence of fault clearing switching actions, with the fault(s) being defined by the fault case and the switching actions automatically calculated by the program. In the latter, the cases are regarded as contingency situations generated by the outage of a selected group of components.

29.8

Comparing Contingency Results

In order to compare contingencies in a fast and easy way, PowerFactory provides a Contingency Comparison function ( ). The Contingency Comparison function is only enabled if the user has previously defined the contingency cases in the Contingency Analysis command, as explained in Sections 29.6 (Creating Contingency Cases Using Fault Cases and Groups) and 29.7 (Creating Contingency Cases Using the Contingency Definition Command). The general handling of the Contingency Comparison function is as follows: 1. Define the contingency cases in the Contingency Analysis command (see Sections 29.6: Creating Contingency Cases Using Fault Cases and Groups and 29.7: Creating Contingency Cases Using the Contingency Definition Command). 2. Click on the Contingency Comparison button ( ). A window will pop up allowing the user to select the required contingency cases (Figure 29.8.1). The selection can correspond to one, several, or all contingency cases.

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Figure 29.8.1: Selection of Contingency Cases for Comparison 3. By clicking on the OK button, the Comparing of Results On/Off button (Figure 29.8.2) is enabled and the selected contingency cases are automatically executed.

Figure 29.8.2: Comparing of Results Button 4. The single line graphic result boxes will display the results, based on the comparison mode and the two compared cases. By default, the comparison is made between the Base Case and the last selected contingency case in the list. 5. To change the comparison mode and/or the cases to be compared, click on the Edit Comparing of Results button (Figure 29.8.2). The Compare dialogue will pop up displaying the current settings. To change the cases to be compared, click on the black arrow pointing down ( ) and select a different case (Figure 29.8.3).

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29.9. RESULT ANALYSIS

Figure 29.8.3: Selection of other Cases for Comparison 6. If the contingency analysis is defined with time phases, the compare dialogue will have the option of selecting the time phase. 7. Once the calculation is reset (for example by either making changes in the model or by clicking on the Reset Calculation button), the comparison mode will be disabled.

29.9

Result Analysis

29.9.1

Predefined Report Formats (Tabular and ASCII Reports)

In PowerFactory the Contingency Analysis function has a special set of predefined report formats that can be launched by clicking on the Report Contingency Analysis Results button ( ), which is illustrated in Figure 29.8.2. The Report Contingency Analysis Results button will only be enabled if the user has previously executed the Contingency Analysis command, as explained in Section 29.3 (Executing Contingency Analyses). Once the reporting of results has been launched, the dialogue window illustrated in Figure 29.9.1 will be displayed.

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Figure 29.9.1: Contingency Analysis Reports Dialogue

The following types of report can be selected: • Maximum Loadings: Only the maximum loaded component (according to the specified loading limit) for each contingency is displayed in a single list. • Loading Violations: All overloaded components (according to the specified loading limit) for each contingency are displayed in a single list. • Voltage Steps: All voltage deviations of terminals (between the base case and the contingency case) for each contingency are displayed in a single list. Reports the highest voltage deviation of terminals (between the base case and the contingency case) considering all contingencies. Any such terminal is reported only once. Only terminals with the highest voltage deviation greater than the specified maximum voltage step are reported. • Maximum Voltages: Reports the greatest voltage violation of a terminal (greater than or equal to the specified voltage limit) considering all contingencies. Any such terminal is reported only once (i.e. it is reported for the contingency causing this violation). • Minimum Voltages: Reports the greatest voltage violation of a terminal (less than or equal to the specified voltage limit) considering all contingencies. Any such terminal is reported only once (i.e. it is reported for the contingency causing this violation). • Maximum Voltage Violations: Reports all voltage violations of a terminal (greater than or equal to the specified upper voltage limit) considering all contingencies. • Minimum Voltage Violations: Reports all voltage violations of a terminal (less than or equal to the specified lower voltage limit) considering all contingencies.

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29.9. RESULT ANALYSIS • Loading Violations per Case: All overloaded components (according to the specified loading limit) for each contingency are displayed in separate lists (i.e. one list per contingency case). • Voltage Violations per Case: All busbars with exceeding voltage (maximum or minimum) are displayed in separate lists. • Generator Effectiveness: Generators having an effectiveness greater than or equal to the specified value (%) are displayed in a single list. • Quad-Booster Effectiveness: Quad-booster transformers having an effectiveness greater than or equal to the specified value (MW/Tap) are displayed in a single list. • Non-convergent Cases: The non-convergent cases of the contingency analysis are displayed in a list.

Figure 29.9.2: Tabular Report of Loading Violations

The tabular format (Figure 29.9.2) for reporting has the following sections: • Header: Identifies the report and its data. • Filter: Represented as drop-down lists, allowing the selection of one item at a time or as "Custom". • Table: Matrix of rows and columns containing cells that can refer to an object and provide actions such as "Edit", "Edit and Browse" and "Mark in Graphic". It also supports copy and paste, scroll features, page up and down keys as well as Ctrl+Pos1, Ctrl+End and HTML view.

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CHAPTER 29. CONTINGENCY ANALYSIS After being executed, the Tabular Report can be exported as HTML format or exported directly to Excel, by using the Select icon ( ). Although the tabular reports are already predefined, the user can modify them if required (by going to the second page of the Report Contingency Analysis Results dialogue and clicking on the blue arrow pointing to the right of the Used Format definition).

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Chapter 30

Reliability Assessment 30.1

Introduction

Reliability assessment involves determining, generally using statistical methods, the total electric interruptions for loads within a power system during an operating period. The interruptions are described by several indices that consider aspects such as: • The number of customers [N]. • The connected load, normally expressed in [kW]. • The duration of the interruptions, normally expressed in [h] = ’hours’. • The amount of power interrupted, expressed in [kW]. • The frequency of interruptions, normally expressed in [1/a] = ’per annum’. • Repair times are normally expressed in [h] = ’hours’. • Probabilities or expectancies are expressed as a fraction or as time per year ([h/a], [min/a]). Network reliability assessment is used to calculate expected interruption frequencies and annual interruptions costs, and to compare alternative network designs. Reliability analysis is an automation and probabilistic extension of contingency evaluation. For such analysis, it is not required to pre-define outage events, instead the tool can automatically choose the outages to consider. The relevance of each outage is considered using statistical data about the expected frequency and duration of outages according to component type. The effect of each outage is analyzed automatically such that the software simulates the protection system and the network operator’s actions to re-supply interrupted customers. Because statistical data regarding the frequency of such events is available, the results can be formulated in probabilistic terms. Note: Reliability assessment tools are commonly used to quantify the impact of power system equipment outages in economic terms. The results of a reliability assessment study may be used to justify investment in network upgrades such as new remote control switches, new lines / transformers, or to assess the performance of under voltage load shedding schemes.

This chapter deals with probabilistic Network Reliability Assessment. For information on PowerFactory ’s deterministic Contingency Analysis, refer to Chapter 29 (Contingency Analysis). The reliability assessment functions can be accessed by selecting Reliability toolbar from the Change Toolbox icon ( ) as illustrated in Figure 30.1.1. DIgSILENT PowerFactory 15, User Manual

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Figure 30.1.1: Reliability Toolbar Selection

The basic user procedure for completing a reliability assessment consists of the following steps as shown in Figure 30.1.2. Steps on the left are compulsory, while steps on the right are optional and can be used to increase the detail of the calculation.

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30.2. PROBABILISTIC RELIABILITY ASSESSMENT TECHNICAL BACKGROUND

Figure 30.1.2: Reliability Assessment User Procedure

These procedures are explained in detail in the following sections.

30.2

Probabilistic Reliability Assessment Technical Background

The Reliability Assessment procedure considers the network topology, protection systems, constraints and stochastic failure and repair models to generate reliability indices. The technical background of the procedure and Stochastic Models is described in this section. Note: A quantity is said to be stochastic when it has a random probability distribution. A simple example of a stochastic quantity is the expected repair duration for an item of equipment, which is based on the total number of repairs and repair duration. This measured data can be used to build Stochastic Models, and perform analysis using statistical calculation methods.

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30.2.1

Reliability Assessment Procedure

The generation of reliability indices, using the Reliability Assessment tool also known as ’reliability analysis’, consists of the following: • Failure modelling. • Load modelling. • System state creation. • Failure Effect Analysis (FEA). • Statistical analysis. • Reporting.

Figure 30.2.1: Reliability Analysis: Basic Flow Diagram

The reliability analysis calculation flow diagram is depicted in Figure 30.2.1. The failure models describe how system components can fail, how often they might fail and how long it takes to repair them when they fail. The load models can consist of a few possible load demands, or can be based on a userdefined load forecast and growth scenarios. The combination of one or more simultaneous faults and a specific load condition is called a ’system state’. Internally, PowerFactory ’s system state generation engine uses the failure models and load models to build a list of relevant system states. Subsequently, the Failure Effect Analysis (FEA) module analyzes the faulted system states by simulating the system reactions to these faults. The FEA takes the power system through a number of post-fault operational states that can include: • Fault clearance by tripping of protection breakers or fuses. • Fault separation by opening separating switches. • Power restoration by closing normally open switches. • Overload alleviation by load transfer and load shedding. • Voltage constraint alleviation by load shedding (only available when ’Distribution’ is selected within the reliability command Basic Options). 688

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30.2. PROBABILISTIC RELIABILITY ASSESSMENT TECHNICAL BACKGROUND The objective of the FEA function is to determine if system faults will lead to load interruptions and if so, which loads will be interrupted and for how long. The results of the FEA are combined with the data that is provided by the system state generation module to create the reliability statistics including indices such as SAIFI, SAIDI and CAIFI. The system state data describes the expected frequency of occurrence of the system state and its expected duration. However, the duration of these system states should not be confused with the interruption duration. For example, a system state for a line outage, perhaps caused by a short-circuit on that line, will have a duration equal to the time needed to repair that line. However, if the line is one of two parallel lines then it is possible that no loads will be interrupted because the parallel line might be able to supply the full load current. Even if the loads are interrupted by the outage, the power could be restored by network reconfiguration - by fault separation and closing a back-feed switch. The interruption duration will then equal the restoration time, and not the repair duration (equivalent to the system state duration).

30.2.2

Stochastic Models

A stochastic reliability model is a statistical representation of the failure rate and repair duration time for a power system component. For example, a line might suffer an outage due to a short-circuit. After the outage, repair will begin and the line will be put into service again after a successful repair. If two states for line A are defined as ’in service’ and ’under repair’, monitoring of the line could result in a time sequence of outages and repairs as depicted in Figure 30.2.2.

Figure 30.2.2: Line availability states are described by the status of the line (in service or under repair). Each of these states lasts for a certain time.

Line A in this example fails at time T1 after which it is repaired and put back into service at T2. It fails again at T3, is repaired again, etc. The repair durations are also called the ’Time To Repair’ or ’TTR’. The service durations 𝑆1 = 𝑇1 , 𝑆2 = 𝑇3 − 𝑇2 , etc. are called the ’life-time’, ’Time To Failure’ or ’TTF’. Both the TTR and the TTF are stochastic quantities. By gathering failure data about a large group of similar components in the power system, statistical information about the TTR and TTF, such as the mean value and the standard deviation, can be calculated. The statistical information is then used to define a Stochastic Model. There are many ways in which to define a Stochastic Model. The so-called ’homogenous Markov-model’ is a highly simplified but generally used model. A homogenous Markov model with two states is defined by: • A constant failure rate 𝜆; and • A constant repair rate 𝜇. These two parameters can be used to calculate the following quantities: • mean time to failure, TTF = 1/𝜆; • mean time to repair, TTR = 1/𝜇; DIgSILENT PowerFactory 15, User Manual

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CHAPTER 30. RELIABILITY ASSESSMENT • availability, P = TTF/(TTF+TTR); • unavailability Q, = TTR/(TTF+TTR); The availability is the fraction of time when the component is in service; the unavailability is the fraction of time when it is in repair; and P+Q = 1.0. Reminder: TTR is the ’Time To Repair’, and TTF is the ’Time To Failure’.

Example If 7500 monitored transformers were to show 140 failures over 10 years, during which a total of 7360 hours was spent on repair, then:

𝜆=

1 1 140 · = 0, 00187 · 10 · 7500 𝑎 𝑎

1 = 536𝑎 𝜆

(30.2)

7360 · ℎ = 52, 6ℎ = 0, 006𝑎 140

(30.3)

𝑇𝑇𝐹 =

𝑇𝑇𝑅 =

1 1 = 167 · 𝑇𝑇𝑅 𝑎

(30.4)

536 = 0, 999989 536 + 0, 006

(30.5)

𝑚𝑖𝑛 0, 006 =6 536 + 0, 006 𝑎

(30.6)

𝜇=

𝑃 =

(30.1)

𝑄=

i.e. the expected outage duration is 6 minutes per annum.

30.2.3

Calculated Results for Reliability Assessment

The network reliability assessment produces two types of indices: • Load point indices. • System indices. These indices are separated into frequency/expectancy indices and energy indices. Furthermore, there are indices to describe the interruption costs. Load point indices are calculated for each load (ElmLod), and are used in the calculation of many system indices. This section describes the simplified equations for the reliability indices. However, note that the PowerFactory reliability assessment calculations use more complex calculation methods. Nevertheless, the simplified equations shown here can be used for hand calculations or to gain insight into the reliability assessment results. 690

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30.2. PROBABILISTIC RELIABILITY ASSESSMENT TECHNICAL BACKGROUND 30.2.3.1

Parameter Definitions

In the definitions for the reliability indices, the following parameters are used: 𝐶𝑖 The number of customers supplied by load point i 𝐴𝑖 The number of affected customers for an interruption at load point i 𝐹 𝑟𝑘 The frequency of occurrence of contingency k 𝑝𝑟𝑘 The probability of occurrence of contingency k C The number of customers A The number of affected customers 𝐿𝑚 The total connected kVA interrupted, for each interruption event, 𝑚 𝑟𝑚 Duration of each interruption event, 𝑚 𝐿𝑇 The total connected kVA supplied 𝑃 𝑐𝑖 Contracted active power at load point i

30.2.3.2

Load Point Frequency and Expectancy Indices

ACIF: Average Customer Interruption Frequency ACIT: Average Customer Interruption Time LPIF: Load Point Interruption Frequency LPIT: Load Point Interruption Time LPIC: Load Point Interruption Costs AID: Average Interruption Duration TCIF: Total Customer Interruption Frequency TCIT: Total Customer Interruption Time TPCONTIF: Total Contracted power Interruption Frequency TPCONTIT: Total Contracted power Interruption Time These indices are defined as follows:

𝐴𝐶𝐼𝐹𝑖 =

∑︁

𝐹 𝑟𝑘 · 𝑓 𝑟𝑎𝑐𝑖,𝑘

𝑈 𝑛𝑖𝑡 : 1/𝑎

(30.7)

𝑘

𝐴𝐶𝐼𝑇𝑖 =

∑︁

8760 · 𝑃 𝑟𝑘 · 𝑓 𝑟𝑎𝑐𝑖,𝑘

𝑈 𝑛𝑖𝑡 : ℎ/𝑎

(30.8)

𝑘

𝐿𝑃 𝐼𝐹𝑖 =

∑︁

𝐹 𝑟𝑘

𝑈 𝑛𝑖𝑡 : 1/𝑎

(30.9)

𝑘

𝐿𝑃 𝐼𝑇𝑖 =

∑︁

8760 · 𝑃 𝑟𝑘

𝑈 𝑛𝑖𝑡 : ℎ/𝑎

(30.10)

𝑘

𝐴𝐼𝐷𝑖 =

𝑇 𝐶𝐼𝐹𝑖 = 𝐴𝐶𝐼𝐹𝑖 · 𝐶𝑖 DIgSILENT PowerFactory 15, User Manual

𝐴𝐶𝐼𝑇𝑖 𝐴𝐶𝐼𝐹𝑖

(30.11)

𝑈 𝑛𝑖𝑡 : 𝐶/𝑎

(30.12) 691

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𝑇 𝐶𝐼𝑇𝑖 = 𝐴𝐶𝐼𝑇𝑖 · 𝐶𝑖

𝑇 𝑃 𝐶𝑂𝑁 𝑇 𝐼𝐹𝑖 =

∑︁

𝑈 𝑛𝑖𝑡 : 𝐶ℎ/𝑎

𝐹 𝑟𝑘 · 𝑓 𝑟𝑎𝑐𝑖,𝑘 · 𝑃 𝑐𝑖

𝑈 𝑛𝑖𝑡 : 𝑀 𝑊/𝑎

(30.13)

(30.14)

𝑘

𝑇 𝑃 𝐶𝑂𝑁 𝑇 𝐼𝑇𝑖 =

∑︁

8760 · 𝑃 𝑟𝑘 · 𝑓 𝑟𝑎𝑐𝑖,𝑘 · 𝑃 𝑐𝑖

𝑈 𝑛𝑖𝑡 : 𝑀 𝑊 ℎ/𝑎

(30.15)

𝑘

where 𝑖 is the load point index 𝑘 is the contingency index 𝑓 𝑟𝑎𝑐𝑖,𝑘 is the fraction of the load which is lost at load point i, for contingency k. For unsupplied loads, or for loads that are shed completely,𝑓 𝑟𝑎𝑐𝑖,𝑘 = 1.0. For loads that are partially shed, 0.0 0 • The probability of double earth fault of the second object is > 0. The frequency for single earth faults and the probability of the second earth fault data can be entered on the ’Earth Fault’ page of every Stochastic Model. Follow these steps to enter data for a Line Stochastic Model: 700

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30.3. SETTING UP THE NETWORK MODEL FOR RELIABILITY ASSESSMENT 1. Open the Stochastic Failure Model for the line (either through the reliability page of the line type or the line elements). 2. Select the Earth Fault page. 3. Enable the option ’Model Earth Faults’ 4. Enter the data for the frequency of single earth faults 5. Enter the data for the conditional probability of a second earth fault 6. Enter the Repair duration in hours. 7. Close the Stochastic Model. Note: The double earth fault is a conditional probability. Therefore, the probability of one occurring in the network is the probability of an earth fault on component A * probability of an double earth fault on component B

30.3.2

How to Create Feeders for Reliability Calculation

When performing a reliability calculation with the ’Distribution’ option set under ’Basic Options’, PowerFactory requires that feeder/s have been defined in the model. To create a feeder: • Right click on the cubicle at the head of the feeder and select the option Define → Feeder ; or • for fast creation of multiple feeders right click the bus the feeder/s are connected to and select the option Define → Feeder. More information on feeders and feeder creation can be found in Chapter 13: Grouping Objects, Section 13.5(Feeders).

30.3.3

Configuring Switches for the Reliability Calculation

A critical component of the Failure Effect Analysis (FEA), is the behaviour of the switches in the network model. Switches in PowerFactory are classified into four different categories: • Circuit Breakers; Typically these are automatic and controlled by relays and through remote communications. They are used for clearing faults and for closing back-feeds for power restoration. • Disconnectors; Used for isolation and power restoration. • Load-Break-Switch; Used for isolation and power restoration. • Switch Disconnector; Used for isolation and power restoration. All switches in PowerFactory are modelled using the StaSwitch or ElmCoup objects. The switch category (CB, disconnector etc) is selected on the basic data page of the switch. The actions that the FEA analysis takes depends on the configuration of these switches and, optionally, the location of protection devices. Configuration steps To configure a switch for reliability analysis follow these steps: 1. Open the dialogue for the switch and select the reliability page. This can be done directly by editing switches modelled explicitly on the single line diagram, or for switches embedded within a cubicle, by right-clicking the cubicle and selecting the option ’edit devices’, to access the switch. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 30. RELIABILITY ASSESSMENT 2. Select the ’Sectionalizing’ option. The following choices are available: • Remote controlled (Stage 1); This option means that the actuation time of this switch is taken from the global ’remote controlled’ switch actuation time. The default time is 1 min but this can be adjusted within the reliability command, see Section 30.4.1: How to run the Reliability Assessment.Typically remote controlled switches are circuit breakers controlled by relays or with communications from a control room. • Indicator of Short Circuit (Stage 2); This option represents a switch that has an external indication of status on the outside of the switch enclosure. This allows the operator/technician to easily identify the switch status and actuate the switch. • Manual (Stage 3); These switches need direct visual inspection to determine their status and therefore take longer to actuate than either stage 1 or stage 2 switches. 3. Select the ’Power Restoration’ option. The following choices are available: • Do not use for power restoration; If this option is selected the switch can only be used for isolation of equipment or load shedding. It will not be used by the FEA calculation to restore power. • From terminal i to j; If this option is selected, the switch will only be used to restore power if the post restoration power flow is in the direction from terminal i to terminal j. The switch will not be used for power restoration in the opposite direction. • From terminal j to i; If this option is selected, the switch will only be used to restore power if the post restoration power flow is in the direction from terminal j to terminal i. The switch will not be used for power restoration in the opposite direction. • Independent of direction; If this option is selected the switch will be used to restore power flow regardless of the direction of the post restoration power flow. 4. Enter the time to actuate switch (Stage 2 and 3 switches only); This field specifies the time taken by the operator to actuate the switch. Note, this excludes the local access and access time if the switch is within a substation. The total actuation time of such a switch is therefore the switch actuation time + the substation access time + the local access time. Note: The Sectionalizing options are only considered when the ’Distribution’ reliability analysis option is selected under ’Basic Options’. If the ’Transmission’ mode is selected, then all switches are assumed to be remote controlled.

30.3.4

Load Modelling for Reliability Assessment

This section provides a general description of the load element parameters that are used by the reliability calculation. The first sub-section describes how to input the number of customers that each load represents and how to classify each load. The second sub-section describes how to define load shedding and transfer parameters.

30.3.4.1

Specifying the Number of Customers for a Load

Many of the reliability indices such as SAIFI and CAIFI are evaluated based on the number of customers interrupted. Therefore, for accurate calculation of these indices it is important to specify the number of customers that each load represents. To do this: 1. Open the dialogue for the target load element. 2. Select the Reliability page. 3. In the ’Number of connected customers’ field, enter the number of customers that this load represents. 702

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30.3. SETTING UP THE NETWORK MODEL FOR RELIABILITY ASSESSMENT 4. Repeat this process for each load in the system you are modelling. Load Classification Every load can be optionally classified into agricultural, commercial, domestic or industrial load. This option does not affect the calculation of the reliability indices and is provided for categorisation purposes only.

30.3.4.2

Specifying Load Shedding and Transfer Parameters

Load transfer and load shedding are used to alleviate violated voltage or thermal constraints caused by the power restoration process. There is a distinction between load transfer for constraint alleviation, such as described in this section, and load transfer for power restoration. Load transfer by isolating a fault and closing a back-stop switch is considered automatically during the fault separation and power restoration phase of the failure effect analysis. If a violated constraint is detected in the post-fault system condition, a search begins for the loads contributing to these overloads. The overloads are then alleviated by either: • Transferring some of these loads, if possible; or • Shedding some of these loads, starting with the lowest priority loads. To define the load shedding parameters follow these steps: 1. Open the reliability page of the load element. 2. Enter the number of load shedding steps using the ’Shedding steps’ list box. For example, four shedding steps means that the load can be shed to 25%, 50%, 75% or 100% of its base value. Infinite shedding steps means that the load can be shed to the exact value required to alleviate the constraint. 3. Enter the ’Load priority’. The reliability algorithm will always try to shed the loads with the lowest priority first. However, high priority loads can still be shed if the algorithm determines this is the only way to alleviate a constraint. 4. Enter the load transfer percentage in the ’Transferable’ parameter. This defines the percentage of this load that can be transferred away from the current network. PowerFactory assumes that the transferred load is picked up by another network that is not modelled, hence load transferring in this way is equivalent to load shedding in terms of constraint alleviation. The difference is that transferred load is still considered as supplied load, whereas shed load is obviously not supplied. 5. Optional: Use the selection control next to ’Alternative Supply (Load)’ to specify an alternative load that picks up all transferred load. Note: There is a critical difference between the transmission reliability and distribution reliability functions. In distribution reliability all constraint alleviation is completed using switch actions, so loads can only be fully shed (switched out) or they remain in service. However, by contrast, the transmission reliability option can shed or transfer a percentage of the load.

30.3.5

Modelling Load Interruption Costs

When supply to a load is interrupted, there is a cost associated with the loss of supply. PowerFactory supports the definition of cost curves for load elements using Energy Tariffs and Time Tariffs. They can DIgSILENT PowerFactory 15, User Manual

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CHAPTER 30. RELIABILITY ASSESSMENT be defined using the ’Tariff’ characteristic on the reliability page of the load element, as discussed in Chapter 16: Parameter Characteristics, Load States, and Tariffs, Section 16.5 (Tariffs). Projects imported from previous versions of PowerFactory may include Vector Characteristics for the definition of cost curves, which are discussed in Chapter 16: Parameter Characteristics, Load States, and Tariffs, Section 16.2.4 (Vector Characteristics with Time Scales).

30.3.6

System Demand and Load States (ComLoadstate)

Considering Multiple System Demand Levels (Optional) If you have defined time-based characteristics for the feeder loads so that the demand changes depending on the study case time, then you might want to also consider using these different demand patterns in the reliability analysis. Because the reliability analysis always analyses a discrete ’system state’, it is normally not practical to consider every possible demand level because the number of discrete states in a practical system is usually very large. Instead, the load demand for a one year period is can be discretized and converted into several so-called ’load states’, and a probability of occurrence for each state. The Reliability Command does not automatically generate the load states. Therefore, if you wish to consider multiple demand levels in your reliability analysis you must first get PowerFactory to generate the load states. There are two methods available for producing load states. The first is by specification of load characteristics for individual loads, and the second is by specification of load distribution states for substations. The procedures for each method is described in Chapter 16: Parameter Characteristics, Load States, and Tariffs; Sections 16.3 (Load States) and 16.4 (Load Distribution States).

30.3.7

Fault Clearance Based on Protection Device Location

The Reliability Calculation has two options for fault clearance: • Use all circuit breakers; or • Use only circuit breakers controlled by protection devices (fuses or relays). The second option is the more realistic option, because only locations within the network that can automatically clear a fault will be used by the reliability calculation to clear the simulated faults. However, you must create protection devices to control each automatic switch for this option to work correctly.

30.3.8

How to Consider Planned Maintenance

The PowerFactory reliability calculation supports the definition and automatic inclusion of planned network maintenance. Maintenance is implemented with a planned outage object. These objects are found within the ’Outages’ sub-folder within the project ’Operational Library’. The following steps describe the procedure for creating a planned outage: 1. On the single line diagram (or within the data manager), select the object (or objects) that you would like to define an outage for. 2. Right-click the selected object/s and from the menu that appears choose the option Define → Planned Outage. The dialogue box for the planned outage will appear. 3. Using the Start Time selection control ’...’, enter the time that the outage begins. 4. Using the End Time selection control ’...’, enter the time that the outage ends. 704

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30.4. RUNNING THE RELIABILITY ASSESSMENT CALCULATION 5. Optional: Adjust the Outage Type. Typically you would leave this on the default ’Outage of Element’ option, but if you wanted to model a generator derating, then you would choose the ’Generator Derating’ option. Note: When the reliability calculation considers outages it creates a unique contingency case for every contingency with the outage applied and also without the outage. For example, for a network with two planned outages and six contingencies there will be a total of 6·3 = 18 contingency cases.

30.3.9

Specifying Individual Component Constraints

The reliability calculation can automatically consider voltage and thermal constraints for the power restoration process. There are two options for specifying constraints applied to branch, terminal, and feeder objects as follows: Global Constraints; All network constraints are based on the constraints specified on the constraints tab of the Reliability Command Dialogue. Individual Constraints; If Individual Constraints are selected for branches, terminals, and / or feeders, constraints should be defined by the user for each relevant object by taking the following steps: 1. Open the reliability page of the target terminal, branch (line/transformer), or feeder. 2. Enter the Max and Min Voltage limits, max loading, or voltage drop/rise for the terminal, branch, or feeder respectively. 3. Click OK to close the dialogue and save the changes.

30.4

Running The Reliability Assessment Calculation

The procedure for using the PowerFactory Reliability Assessment tool and analyzing the results generated by the tool is described in this section.

30.4.1

How to run the Reliability Assessment

In PowerFactory the network Reliability Analysis is completed using the Reliability Assessment command (ComRel3 ). This command is found on the ’Reliability Analysis’ toolbar. Alternatively, the commands can be executed for a single element by right-clicking the element and selecting Calculate → Reliability Assessment or → Optimal Power Restoration. The options for the reliability command that are presented within its dialogue are described in the following sub-sections.

30.4.1.1

Basic Options

The following options are available on the Basic Options page Reliability Assessment Command dialogue. Method Connectivity analysis: This option enables failure effect analysis without considering constraints. A load is assumed to be supplied if it is connected to a source of power before a contingency, and assumed to undergo a loss of supply if the process of fault clearance separates the load from all DIgSILENT PowerFactory 15, User Manual

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CHAPTER 30. RELIABILITY ASSESSMENT power sources. Because constraints are not considered, no load-flow is required for this option and hence the analysis will be faster than when using the alternative load-flow analysis option. Load flow analysis: This option is the same as the connectivity analysis, except that constraints are considered by completing load-flows for each contingency. Loads might be disconnected to alleviate voltage or thermal constraints. For the transmission analysis option, Generator re-dispatch, load transfer and load shedding are used to alleviate overloads. Calculation time period Complete year: The reliability calculation is performed for the current year specified in the ’Date/Time of the Calculation Case’. This can be accessed and the date and time changed by clicking the button. Single Point in Time: The Reliability Calculation is completed for the network in its current state at the actual time specified by the ’Date/Time of the Calculation Case’. Note: If load states or maintenance plans are not created and considered, then these options make no difference because the reliability calculation is always completed at the single specified time.

Load Flow This button is a link to the load-flow calculation command used for the analysis. The load demand is calculated using this load-flow. In addition, its settings are used for the constraint evaluation load-flows. Network Distribution: The reliability assessment will try to remove overloading at components and voltage violations (at terminals) by optimizing the switch positions in the radial system. If constraints occur in the power restoration process, loads will be shed by opening available switches. This option is the recommended analysis option for distribution and medium voltage networks. Note: The reliability command optimizes switch positions based on load shedding priorities, and not network losses.

Transmission: Thermal overloads are removed by generator re-dispatch, load transfer and load shedding. First generator re-dispatch and load transfer is attempted. If these cannot be completed or do not remove the thermal overload, load shedding actions will occur. Generator re-dispatch and load transfer do not affect the reliability indices. However, by contrast, load shedding leads to unsupplied loads and therefore affects the reliability indices. Automatic Contingency Definition (ComContingency ) The ’Selection’ list presents three possible options for the contingency definition. These are: • Whole system: PowerFactory will automatically create a contingency event for every object that has a Stochastic Model defined. • Single Grid: Selecting this option shows a selection control. Now you can select a single grid and only contingencies for objects in this grid will be created. • User Defined: Selecting this option shows a selection control. Now you can select a set of objects (SetSelect), and contingencies will be created for each of these objects that has a Stochastic Model defined. 706

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30.4. RUNNING THE RELIABILITY ASSESSMENT CALCULATION In addition to the above contingency definition options, the automatic contingency definition can be further controlled with the following checkboxes: • Busbars/Terminals; You must enable this flag for PowerFactory to create Busbar and terminal contingencies. • Lines/Cables; You must enable this flag for PowerFactory to create Line/Cable contingencies. • Transformers; You must enable this flag for PowerFactory to create transformer contingencies. • Common Mode; You must enable this flag for PowerFactory to create Common Mode contingencies. See Common Mode Stochastic Model (StoCommon) for more information. • Independent second failures; You must enable this flag for PowerFactory to consider n-2 outages in addition to n-1 outages. Caution: n-2 outages for all combinations of n-1 outages are considered. This means that for a system of n contingencies there are (𝑛 · (𝑛 − 1))/2) + 𝑛, contingencies to consider. This equation is quadratic, and so to minimize the required time for computation this option is disabled by default. • Double-earth faults; You must enable this flag for PowerFactory to consider double-earth faults. See Double Earth Faults for more information. • Protection/switching failures; You must enable this flag for PowerFactory to consider protection devices or circuit breakers’ failure to operate. See Protection/Switch Failures for more information.

30.4.1.2

Outputs

The following options are available on the Outputs tab of the Reliability command. Results This option allows the selection of the result element (ElmRes) where the results of the reliability analysis will be stored. Normally, PowerFactory will create a result object within the active study case. Perform Evaluation of Result File The Reliability Analysis automatically writes all simulation results to a result object specified above. After completing the Reliability Calculation, PowerFactory automatically evaluates the result object to compute the reliability indices. This button allows you to re-evaluate a results file that has previously been created by this or another reliability calculation command. The benefit of this is that you do not have to re-run the reliability calculation (which can be time consuming compared to the results object evaluation) if you only want to recalculate the indices from an already completed calculation. Output Displays the form used for the output report. Report settings can be inspected and the format selected button. by clicking on the Recording Limits These options define when PowerFactory will record bus voltages and line loadings in the reliability assessment result object. For example, if the loading limit is specified as 80%, then line loadings will only be recorded on lines where the calculated loading is greater than 80%.

30.4.1.3

FEA

A failure effect analysis (FEA) is made for each system state that occurs during the state enumeration. The configuration options are explained below. Fault Clearance Breakers DIgSILENT PowerFactory 15, User Manual

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CHAPTER 30. RELIABILITY ASSESSMENT Use all circuit breakers: All switches in the system whose Usage is set to Circuit Breaker can be used for fault clearance. Use only circuit breakers with protection device: All circuit breakers in the system which are controlled by a protection device (fuse or relay) can be used for fault clearance. Fault Separation/Power Restoration This option will only be enabled if Automatic Power Restoration is enabled on the Advanced Options Tab. Concurrent Switch Actions: It is assumed that the switching actions can be performed immediately following the specified switching time. However, a switch can be closed for power restoration only after the faulted element was disconnected. The analogy for this mode, is if there were a large number of operators in the field that were able to communicate with each other to coordinate the switching actions as quickly as possible. Therefore, this option gives an optimistic assessment of the ’smart power restoration’. Sequential Switch Actions: It is assumed that all switching actions are performed sequentially. The analogy for this mode, is if there is only a single operator in the field and they are required to complete all switching. The fault separation and power restoration is therefore slower when using this mode compared with the ’concurrent’ mode. Consider Sectionalizing (Distribution analysis only) If enabled, the FEA considers the switch sectionalizing stage when attempting fault separation and power restoration. First sectionalizing is attempted using only stage 1 switches, if this is not successful then stage 1 and 2 switches are used. Finally, if this is not successful, then stage 1, 2 and 3 switches are used. Time to open remote controlled switches The time (in minutes) taken to open remote controlled switches.

30.4.1.4

Costs

Costs for energy not supplied If this option is selected, an Energy Tariff can be selected. Energy Tariffs are discussed in Chapter 16: Parameter Characteristics, Load States, and Tariffs, Section 16.5.2(Defining Energy Tariffs). Costs for loads If this option is selected, a Global cost curve for all loads can be selected. Alternatively, ’Individual cost curve per load’ may be selected, allowing the user to define tariffs for individual loads. In both cases, a Time Tariff or Energy Tariff may be defined, as discussed in Chapter 16: Parameter Characteristics, Load States, and Tariffs, Section 16.5 (Tariffs).

30.4.1.5

Constraints

The settings for global constraints are defined within this page. The options are as follows: Consider Thermal Constraints (Loading) If this option is enabled, thermal constraints are considered by the FEA. Global constraints for all components: Constraints specified in ’Max thermal loading of components’ apply to all components in percent value. 708

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30.4. RUNNING THE RELIABILITY ASSESSMENT CALCULATION Individual constraint per component: The maximum thermal loading limit is considered for each component separately. This loading limit can be found on the Reliability tab of each component. Consider Voltage Limits (Terminals) If this option is enabled terminal voltage limits are considered by the FEA. Global Constraint for all terminals: Constraints specified in Lower and Upper Limit of allowed voltage in p.u. that will apply to all terminals. Individual Constraint per terminal: Voltage constraints are considered for each terminal separately. These constraints can be found on the Reliability tab of each terminal. Consider Voltage Drop/Rise If this option is enabled feeder voltage limits are considered by the FEA. Global Constraint for all feeders: Constraints specified in Maximum Voltage Drop and Rise in percent value that will apply to all feeders. Individual Constraint per feeder: Voltage Drop/Rise constraints are considered for each feeder separately. These constraints can be found on the Reliability tab of each feeder. Ignore all constraints for Constraints are ignored for all terminals and components below the entered voltage level. Nominal voltage below or equal to: The voltage level in kV is specified here if ’Ignore all constraints for...’ is enabled. Note: Voltage constraints are only available when the ’Distribution’ analysis option is selected under ’Basic Options’. Thermal constraints are available when either the ’Transmission’ or ’Distribution’ analysis option is selected.

30.4.1.6

Maintenance

This tab allows you to enable or disable the consideration of Maintenance based on the Planned Outages you have defined. See Section 30.3.9, for more information on defining planned outages. The following options are available on this page: Consider Maintenance If enabled, all maintenance that falls in the selected time period, whether it’s a year or a single point in time, is considered. Show used planned outages: When clicked, this button will show a list of all planned outages that will be considered by the calculation. Show all planned outages: When clicked, this button will show a list of all planned outages created in the project, including those not considered by the analysis because they fall outside of the selected time period.

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Load Data

If the Reliability Calculation option ’Complete Year’ is selected on the basic options page, then the following options are available on the Load Data page. Consider Load States / Consider Distribution States Enable the relevant flag to consider load states or load distribution states in the reliability calculation. The reliability calculation does not create load states automatically. If this flag is enabled but the states have not been created, then an error will be printed to the output window and the reliability calculation will stop. Otherwise the following two buttons are available. Update/creation of States Manually: If selected, a button ’Create load states’ will be available. When clicked, it launches the ’Load state creation’ command after closing the reliability command (see Chapter 16 for more information on load state creation). Automatically before running reliability calculation: When selected, a pointer to the load state creation command is available.

30.4.1.8

Advanced Options

Failures, correction of forced outage rate This option performs an automatic correction/normalization of the reliability indices to allow for the fact that not all unlikely but possible contingencies have been considered in the analysis. For instance, n-3 contingencies have a non-zero probability. Note: ’Forced outage’ refers to the unplanned removal of a primary component from the system due to one or more failures in the system.

Fault Clearance/ Automatic Power Restoration Do not save corresponding switch events: Results of internal nodes of substations will not be written to the result file. This minimizes the amount of objects created in the database while performing calculations with many contingencies caused by big networks (e.g if independent second failures or double earth faults are enabled). Save corresponding switch events: Corresponding switch events will be saved in the database while performing calculations. Automatic Power Restoration If enabled, automatic power restoration will be considered. Calculate Existing Contingencies (Do not create contingencies) If enabled, the existing contingencies inside the reliability command will be used in the analysis. Note that the options for automatic contingency definition on the Basic Options tab disappears. Trace Functionality (Jump to Last Step) A user-defined ’Time delay in animation’ can be entered to delay the animation of power restorations when the Jump to Last Step icon ( is pressed. Switch/Load events 710

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30.4. RUNNING THE RELIABILITY ASSESSMENT CALCULATION Delete switch events: Removes all switch events associated with the contingencies stored inside the command. Delete load events: Removes all load events associated with the contingencies stored inside the command. Loadflow Analysis, Overloadings Consider branch if loadings exceeds: If there are overloaded elements in the system, these overloadings should be removed through overload alleviation. Branches whose loading exceeds this limit, are considered by the overload alleviation algorithm. A reliability assessment will be started when the Execute button is pressed. The calculation time required for a reliability assessment can range from a few seconds for a small network only considering n-1 contingencies, to several hours for a large network considering n-2 contingencies. A reliability assessment calculation can be interrupted by clicking on the Break icon ( ) on the main toolbar.

30.4.2

Viewing the Load Point Indices

You can view the Reliability Assessment Load Point Indices in two ways: in the load result boxes in single line graphic, or in the data browser (data manager or load filter). This sub-section describes both of these methods. Method 1 - View the Load Point Indices in the Single Line Diagram After you have executed the Reliability Assessment Calculation, all loads within the Network Single Line Graphic, will show the following load point indices: • AID: Average Interruption Duration. • LPIF: Load Point Interruption Frequency. • LPIT: Load Point Interruption Time. • LPIC: Load Point Interruption Costs. As usual, with PowerFactory result boxes, you can hover the mouse pointer over the result box to show an enlarged popup of the results. This is demonstrated in Figure 30.4.1

Figure 30.4.1: Single Line Diagram Graphic Showing the Load Point Indices Results DIgSILENT PowerFactory 15, User Manual

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Note: You can show any of the calculated load point indices in the load result boxes. To do this modify the displayed variables as described in Chapter 17: Reporting and Visualizing Results, Section 17.4.3(Examples of Variable Selection)

Method 2 - View the Load Point Indices in the Data Browser To view the load point indices in the Data Browser (as a selectable spreadsheet list), follow these steps: from the Edit Relevant Objects for Selection button 1. Select the load element icon all loads considered in the calculation will appear. Calculation

. A list of

2. Choose the Flexible Data tab. Calculated Load Point Indices for each load will appear in Green Font text. By default, not all available load point indices will be shown. 3. Optional: Click the Define Flexible Data button

, to show all available variables.

4. Optional: Add more variables to the Selected Variables by double-clicking the variable in the Available Variables window. 5. Optional: Click OK to view the result variables in the data browser.

30.4.3

Viewing the System Reliability Indices (Spreadsheet format)

The System Reliability Indices can be viewed for the whole system, individual grids, or for individual feeders. Viewing these results is described in this sub-section. To View Complete System Reliability Indices Follow these steps to view the complete system reliability indices: 1. Select the Grids icon from the Edit Relevant Objects for Calculation button located on the main toolbar. A list of all grids in the network model and a summary grid will appear. 2. Click the Flexible Data tab. 3. Click the Define Flexible Data button

to show the variable selection dialogue.

4. Click the Reliability tab (if not already selected). 5. Choose the variable set Calculation Parameter, from the list selection control in the ’Filter for’ section. A list of available reliability indices will appear. 6. Select the indices that you wish to view, and double click them to move them to the Selected Variables window. 7. Click OK to view the result variables in the data browser. Note: Steps 3-7 are only required the first time you want to view the system reliability indices, or if you want to change the displayed variables. PowerFactory ’remembers’ these settings within each project.

To View Feeder Reliability Indices Reliability indices can also be viewed for each Feeder. To do this:

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30.4. RUNNING THE RELIABILITY ASSESSMENT CALCULATION 1. Select the Feeder icon from the Edit Relevant Objects for Calculation button located on the main toolbar. A dialog box with a list of all feeders in the network model will appear. 2. Click the Flexible Data tab. to show the variable selection dialogue.

3. Click the Define Flexible Data button

4. Click the Reliability tab (if not already selected). 5. Choose the variable set Calculation Parameter, from the list selection control in the Filter for section. A list of available reliability indices will appear. 6. Select the indices that you wish to view, and double click them to move them to the Selected Variables window. 7. Click OK to view the result variables in the data browser. Note: Steps 3-7 are only required the first time you want to view the Feeder reliability indices, or if you want to change the displayed variables. PowerFactory ’remembers’ these settings within each project.

30.4.4

Printing ASCII Reliability Reports

PowerFactory has three built-in ASCII Reliability Reports that you can use to show detailed print outs of the Reliability Calculation results. To do this, follow these steps: 1. Click the Output Calculation Analysis icon available reports will appear.

on the main toolbar. A dialogue box showing the

2. Choose the report that you want to view. 3. Click Execute. The selected ASCII report will be printed to the PowerFactory Output Window. Note: ASCII reports can be copied into a word processing tool directly from the Output Window. However, for a more professional look, try printing the report directly to PDF format from the Output Window.

30.4.5

Using the Colouring modes to aid Reliability Analysis

There are several colouring modes that can aid you when using the reliability assessment functions. These are: • Colouring according to Feeders; Use this to identify each Feeder and to see which feeder picks up load when back-feed switches are closed. • Colouring according to Connected Grid Components; Use this to identify de-energized sections of the network during the fault isolation, separation and power restoration. • Switches, type of usage. Use this mode to check the type of switches in the system when they are not modelled explicitly in the single line diagram. To Colour According to Feeders 1. Click the Diagram Colouring button DIgSILENT PowerFactory 15, User Manual

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CHAPTER 30. RELIABILITY ASSESSMENT 2. Select the tab for the function you want to show the colouring mode for. For example, if you want the feeder colouring to appear before a calculation, then select the Basic Data tab. If you want the colouring to appear after a load-flow choose the load-flow tab. 3. Check the 3. Other box and select Topology from the drop down list. 4. Select Feeders in the second drop down box. 5. Optional: To change the feeder colour settings click the colour settings button. You can double click the displayed colours in the colour column and select a different colour for each feeder as desired. 6. Click OK to close the Diagram Colouring dialogue and save your changes. To Colour According to Connected Grid Components The Connected Grid Components colouring mode displays all the network components that are electrically connected together in the same colour. Other components are not coloured. To enable this mode: 1. Click the Diagram Colouring button

. The diagram colouring dialog will appear.

2. Select the load-flow tab. 3. Check the 3. Other box and select Topology from the drop down list. 4. Select Connected Grid Components in the second drop down box. 5. Click OK to close the Diagram Colouring dialogue and save your changes. To Colour According to Switch Type The Switches: type of usage colouring mode displays all switches in the network with a different colour depending on their switch type. For instance circuit breakers will be displayed in a different colour to disconnectors. To enable this mode: 1. Click the Diagram Colouring button

. The diagram colouring dialog will appear.

2. Select the tab for the function you want to show the colouring mode for. For example, if you want the switch type colouring to appear before a calculation, then select the Basic Data tab. If you want the colouring to appear after a load-flow choose the load-flow tab. 3. Check the 3. Other box and select Secondary Equipment from the drop down list. 4. Select Switches, Type of Usage in the second drop down box. 5. Optional: To change the switch colour settings, click the colour settings button. You can double click the displayed colours in the colour column and select a different colour for each switch type as desired. 6. Click OK to close the Diagram Colouring dialogue and save your changes.

30.4.6

Using the Contribution to Reliability Indices Script

It can be useful to analyze the influence of a particular component or group of components on the calculated reliability indices. This enables the identification of components that can be targeted for upgrade to improve reliability, or to examine the impact of improved switch automation for example. This sub-section describes the built-in DPL script that can be used for these purposes. To Start the Contribution to Reliability Indices Script 714

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30.4. RUNNING THE RELIABILITY ASSESSMENT CALCULATION 1. Execute a Reliability Assessment Calculation (or ensure that you activate a study case where a reliability analysis has previously been completed). from the main toolbar. Depending on 2. Click the Edit Relevant Objects for Calculation button whether you want to view the contributions by Feeder, Grids, Areas or Zone, choose one of the following icons from the list of icons that appears: • For Grids choose the • For Feeders choose the

icon. icon.

• For Zones choose the

icon.

• For Areas choose the

icon.

3. In the window that appears, select the object/s that you want to show the reliability indices contributions. 4. Right-click one of the selected object icons. A menu will appear. 5. Choose Execute DPL scripts. A window displaying a list of DPL scripts will appear. 6. Select the Contribution to Reliability Indices Script and click OK. The script dialogue box will appear. The available options are explained in the next section. How to Configure and Run the Contribution to Reliability Indices Script 1. Enter ’1’ in the value column for ’calcSystemIndices’ parameter to make the script print the system indices results. ’0’ suppresses the printing of the system indices. 2. Enter ’1’ in the value column for ’calcEnergyIndices’ parameter to make the script print the Energy indices results. ’0’ suppresses the printing of the Energy indices. 3. Enter ’1’ in the value column for ’outputComponentClasses’ to make the script display contributions from each class such as lines, cable, transformers. ’0’ suppresses the printing of the class information. 4. Enter ’1’ in the value column for ’outputIndivComponents’ parameter to make the script print the results indices for each object in the selected area. ’0’ suppresses the printing of the individual indices. 5. Optional: Enter ’1’ in the ’outputPercentages’ column to display the results from the script in percent format. 6. Optional: Enter a percent threshold in the ’outputThreshold’ column to limit the printed results to those above a specific threshold. 7. Click Execute to run the script. The results are printed to the PowerFactory output window.

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Chapter 31

Optimal Power Restoration The optimal power restoration functions can be accessed by activating the Optimal Power Restoration toolbar using the icon on the toolbar selection control as illustrated in Figure 31.0.1

Figure 31.0.1: Optimal Power Restoration Selection

31.1

Failure Effect Analysis

The simulation of the system response to specific contingencies (ComContingency ) is called ’Failure Effect Analysis’ (FEA). The System State Enumeration algorithm uses the FEA engine to analyze the following steps after a contingency: • Fault Clearance; • Fault Isolation; • Power Restoration; • Overload Alleviation; • Voltage Constraint Alleviation; • Load Transfer; • Load Shedding; DIgSILENT PowerFactory 15, User Manual

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CHAPTER 31. OPTIMAL POWER RESTORATION FEA analysis for the network assessment can consider or ignore constraints. For overload alleviation, the algorithm uses an AC load flow to search for overloaded branches and if any are identified then it attempts to resolve them, firstly by load transfer and secondly by load shedding. If constraints are not considered by the FEA, then a load-flow for each state is not required and consequently the simulation is much faster. For every simulated failure, a contingency is created by the FEA algorithm. If the calculation uses load characteristics, a contingency is created for every combination of failure and load state. Likewise, when maintenance (planned outages) are considered, there are more states for each outage and contingency combination. Fault Clearance The fault clearance step of the FEA assumes 100% selectivity of the protection. Therefore, it is assumed that the relays nearest to the failure will clear the fault. If protection/switching failures are considered in the FEA, it is assumed that the next closest protection device (after the failed device) has 100% selectivity. As described in (Protection/Switch Failures), PowerFactory does not consider separate switch and protection failures, instead these are lumped together. In the pre-processing phase of the reliability assessment, all breakers in the system that can be tripped by a relay, or fuse are marked as ’protection breakers’. To clear the fault, the FEA starts a topological search from the faulted component/s to identify the closest protection breaker/s that can clear the fault. These breaker/s are then opened to end the fault clearance phase of the FEA. If it is not possible to isolate the fault because there are no appropriate protection breakers, then an error message will be printed and the reliability assessment will end. Fault Isolation The next step of the FEA is to attempt to restore power to healthy network sections. It does this by separating the faulted section from the healthy section by opening sectionalizing switches. The fault separation procedure uses the same topological search for switches as the fault clearance phase. The fault separation phase starts a topological search from the faulted components to identify the closest switches that will isolate the fault. These switches are subsequently opened. Note, all closed switches can be used to separate the faulted area. The area that is enclosed by the identified fault separation switches is called the ’separated area’. The separated area is smaller than, or equal to, the ’protected area’. It will never extend beyond the ’protected area’. The healthy section which is inside the ’protected area’, but outside of the ’separated area’ is called the ’restorable area’ because power can be restored to this area. Power Restoration The Power Restoration process of the FEA energizes the healthy areas of the system after the fault separation process has isolated the faulted area. Note that only open switches that are enabled for use in power restoration will be considered by PowerFactory as candidate switches for power restoration. Additionally, PowerFactory uses a ’smart power restoration’ procedure that also considers the direction of the power restoration and the priority (stage) of the switch. The fastest candidate switch is always selected when there is more than one restoration alternative. Each restorable area that is reconnected to the supplied network is called a ’restored’ area. For more information about the switch configuration for smart power restoration, see Section 30.3.3. If switching actions are not possible in order to return loads and terminals in a separated area to service, then these loads and terminals will remain interrupted for the mean duration of the repair, which is normally several hours. However, if switching actions are possible to return the loads and terminals to service, they will only be interrupted for the time needed to open all separators and to close all power restoration switches. The effects of network upgrades, including improved automation and remote control of switches (by lowering switch actuation times), can be analyzed.

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31.1. FAILURE EFFECT ANALYSIS An Optimal Power Restoration can also be conducted for a single contingency from outside the reliability calculation through the Optimal Power Restoration command shown in Figure 31.0.1, or by right-clicking an element and selecting Calculate → Optimal Power Restoration. Overload Alleviation If the power restoration does not cause any thermal overloads or voltage violations (if applicable), then the FEA can proceed to calculate the statistics for that state and then analyze the next state. However, if thermal constraints are enabled, then PowerFactory will complete load-flows to check that all components are still within their thermal capability after the power restoration is complete. If necessary, load transferring, partial or full load shedding might be required to alleviate the thermal over-load. Note load transferring and partial load shedding are only considered when ’Transmission’ is selected in the Reliability command Basic Options. The distribution option considers only discrete switch actions. Therefore, loads must be fully shed or remain in service. Voltage Constraint Alleviation (Distribution Option only) If the ’Distribution’ option is selected in ’Basic Options’, voltage constraints for busbars/terminals and feeders can be considered in addition to thermal constraints. The voltage constraint alleviation process is similar to the thermal overload alleviation process, where loads will be shed if necessary to maintain system voltages within the defined limits. Load Transfer (Transmission Option only) In some cases, load transfer switches and/or the alternative feeders are not included in the network model where reliability assessment is completed. In these cases, the automatic power restoration cannot switch an unsupplied load to an alternative supply. An example is when a (sub-)transmission network is analyzed and the connected distribution networks are modelled as single lumped loads. In this scenario, transfer switches that connect two distribution networks will not be visible. Therefore, the possibility of transferring parts of the lumped load model to other feeders can be modelled by entering a transfer percentage at each lumped load. This transfer percentage defines the portion of the lumped load that can be transferred ’away’ from the analyzed network, without specifying to which feeder/s the portion is transferred. The use of the load transfer percentage (parameter name: Transferable on the load element’s Reliability tab) is only valid when load transfer is not expected to result in an overloading of the feeders which pick up the transferred loads. Load transfer is used in the overload alleviation prior to the calculation of power at risk (see the following section for further information). The power at risk is considered to be zero if all overloads in the post-fault condition can be alleviated by load transfers alone. Load Shedding There are three basic variations of shedding that can be used: • Optimal load shedding. • Priority optimal load shedding. • Discrete optimal load shedding. Optimal load shedding presumes that all loads can be shed precisely (an infinite number of steps). PowerFactory attempts to find a solution that alleviates the overload with the lowest amount of load shed. PowerFactory uses linear sensitivity indices to first select those loads with any contribution to overloading. A linear optimization is then started to find the best shedding option. The resulting minimum amount of shed load is called the ’Power Shed’, because it equals the minimum amount of load that must be shed to alleviate overloads after the power restoration. The power shed is multiplied by the duration DIgSILENT PowerFactory 15, User Manual

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CHAPTER 31. OPTIMAL POWER RESTORATION of the system state to get the ’Energy Shed’. The total energy shed for all possible system states is reported after the reliability assessment is complete, and is referred to as the ’System Energy Shed’ (SES). Loads are shed automatically based on their allocated priority, with PowerFactory attempting to shed low priority loads, prior to high priority loads wherever possible. In the transmission reliability option, loads can be partially or fully shed, whereas in the distribution option, loads can only be fully shed. Example Figure 31.1.1 shows a simple network containing four loads, several circuit breakers (CB) and disconnectors (DS) and a back-feed switch (BF).

Figure 31.1.1: Short-Circuit on Ln4

Fault clearance The area isolated by the fault clearance procedure is called the ’protected area’. Figure 31.1.2 shows the example network after the fault clearance functions have opened the protection breaker ’CB1’. The protected area is the area containing all switches, lines and loads between ’CB1’ and the back-feed switch, ’BF’. Therefore, during the clearance of this fault, loads 1, 2, and 3 are interrupted.

Figure 31.1.2: Protected Area

Fault Isolation Figure 31.1.3 shows the example network with the separation switches, ’DS2’ and ’DS4’ open. The separated area now only contains the faulted line, Ln4. There are now two restorable areas following 720

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31.1. FAILURE EFFECT ANALYSIS the fault separation; the area which contains load 1, and the area which contains loads 2 and 3.

Figure 31.1.3: Separated Area Highlighted

Power Restoration After the fault separation phase is complete, the following switch actions are required to restore power to the two separate ’restorable’ areas: • Separation switch ’DS2’ is ’remote-controlled’ and has a switching time of 3 minutes. • Power to load 1 is restored by (re)closing the protection breaker, ’CB1’ which is also remote controlled. • Load 1 is therefore restored in 3 minutes (=0.05 hours). • Power to load 2 and 3 is restored by closing the back-feed switch, ’BF’. • Because the back-feed switch has a actuation time of 30 minutes, loads 2 and 3 are restored in 0.5 hours. The network is now in the post-fault condition as illustrated in Figure 31.1.4.

Figure 31.1.4: Power Restoration by Back-Feed Switch BF1 and CB1

Overload Alleviation and Load Shedding

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CHAPTER 31. OPTIMAL POWER RESTORATION Figure 31.1.5 shows a line overload in the post-fault condition in the example network: line ’Ln1’ is loaded to 113%.

Figure 31.1.5: Overloaded Post-Fault Condition

In this example, loads 1, 2, 3 and 4 all contribute to the line overload on LN1, and consequently load would be shed based on load shedding options and priorities set by the user to alleviate the constraint.

31.2

Animated Tracing of Individual Cases

After the Reliability Analysis has completed, it is possible to view the fault clearance, fault separation, power restoration and load shedding actions completed by the algorithm for each contingency. To do this: 1. Click the Fault Trace button on the Optimal Power Restoration toolbar. A list of available contingencies will appear in a new window. 2. Select the contingency to consider and click OK. The network will be initialized to the state before the inception of the fault. 3. Click the Next Step button to advance to the next system state. This will usually show the system state immediately after the protection has operated and cleared the fault. 4. Click the Next Step

button to advance through more steps, each click advances one time step.

5. To stop the fault trace, click the Stop Trace

31.3

button.

Optimal RCS Placement

Following a Backbone Calculation (see Section 35.5), an Optimal Remote Control Switch (RCS) Placement can be performed to optimize placement of remote control switches within a feeder/s. The calculation optimizes placement of a fixed number or optimal number of switches per feeder or backbone, with an objective function that minimizes Energy Not Supplied (ENS), balances ENS, or minimizes Expected Interruption Costs (EIC). The Optimal RCS Placement command is a heuristic planning tool, and may precede a detailed reliability analysis. To conduct an Optimal RCS Placement, reliability data should be specified on the Reliability page of line elements (outages of other elements are not considered). See Chapter 30: Reliability Assessment, Section 30.3 for details. 722

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31.3. OPTIMAL RCS PLACEMENT If the cost of interrupted load is to be considered, a global Energy Tariff must be defined, see Chapter 16, Section 16.5.2: Defining Energy Tariffs for details. The Optimal RCS command can be selected under Optimal Power Restoration toolbar, as shown on Figure 31.0.1 This section describes the Optimal RCS Placement objective function and command dialogues, and provides an example calculation. Note: The Optimal RCS calculation requires that feeder is supposed to be operated radially be selected on the Feeder Basic Options page.

31.3.1

Basic Options Page

Calculate optimal RCS Specify all Feeders or a user-defined set of Feeder/s for the Optimal RCS calculation. To show the Backbones to be considered by the calculation, select Active Backbones. Objective Function : The objective function of the Optimal RCS Placement command can be set to either: • Minimize ENS by installing a specified number of RCS per feeder / backbone to minimize the Energy Not Supplied. • Balance ENS by installing an optimal or fixed number of RCS per feeder / backbone to balance the Energy Not Supplied. This option may be used in some circumstances to plan the network in a way that considers connections with many (or large) customers and connections with few (or small) customers equitably. • Minimize EIC by installing an optimal or fixed number of RCS per feeder / backbone to minimize the Expected Interruption Cost. – If this option is selected, a global Energy Tariff must be defined (see Chapter 16, Section 16.5.2: Defining Energy Tariffs). Number of RCS: • With an objective function to Minimize ENS, specify: – Number of new RCS per feeder / backbone. • With an objective function to Balance ENS or Minimize EIC, select to either Optimize number of RCS or Fix number of new RCS. – Specify the Number or Maximum number of new RCS per feeder / backbone. – If the objective function is set to Minimize EIC, enter the Yearly costs per RCS in $ per annum. Recording of results • Select calculate results only to perform a calculation without making an modifications to the network. • Select save results in variations to save the results to a Variation. Note that by default the variation will be inactive after running the Optimal RCS Placement. • Select to change existing network to change the existing network. Note that this changes object data in the base network. DIgSILENT PowerFactory 15, User Manual

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31.3.2

Output Page

Results A reference (pointer) to the result object. Report (Optionally) select the format of results printed to the output window. The report provides details of the recommended remote control switches and their costs, and depending on the selected objective function, energy not supplied or interruption costs results.

31.3.3

Advanced Options Page

Determine optimal RCS Select to either determine optimal RCS per feeder or per backbone. Note that the calculation is conducted once for each feeder in the feeder selection from the Basic Options page. Optimization of RCS of feeders Select to either optimize RCS for all backbones, or only for backbones up to a specified order (in which case, define the maximum order). Note that if more than one backbone has been created for a feeder, the main backbone will have order “1", the second “best" candidate has order “2", and so on. Consider existing RCS on participating backbones: Optionally select to consider existing RCS on participating backbones. If not selected, the RCS Placement will be performed “from scratch", without considering existing RCSŠs. Detailed output of results: Optionally select detailed output mode to output additional details by “Section", such as ENS, FOR, and EIC (depending on the optimization option selected). Switching Time: Set the Time to actuate RCS and Time to actuate manual switches (applied for all switches). These parameters are used by the calculation to determine ENS and EIC. Load flow calculation Pointer to load-flow command (note for balanced calculations only).

31.3.4

Example Optimal RCS Calculation

Consider the simple example shown in Figure 31.3.1 where two feeders with three loads each are separated via three open points. Line outage rates and load parameters have been defined. To illustrate line Forced Outage Rates, from the main menu select View → Diagram Colouring (or select the Diagram Colouring icon). Under 3. Other select Primary Equipment → Forced Outage Rate. In the example, there is a requirement to install a single Remote Control Switch (RCS) on each feeder to minimize the ENS.

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31.4. OPTIMAL MANUAL RESTORATION

Figure 31.3.1: Example Optimal RCS Model

To calculate the optimal location(s) for remote controlled switches, a Backbone Calculation for all feeders based on network structure is first executed (see Section 35.5 for details of how to run the Backbone Calculation). Next, an Optimal RCS calculation is executed for all feeders, with an objective function to Minimize ENS, limited to 1 RCS per backbone. Note that the calculation will run twice in this example (once for each feeder), and so two RCSŠs will be recommended. The calculation simulates outages of each line, and calculates the ENS for placement of RCSŠs at each location. In order to mitigate the impact of outages (in particular, from the “problem line" Line(1)) the calculation recommends installation of remote control switches at locations “Switch2" and “Switch5" to minimize the ENS.

31.4

Optimal Manual Restoration

The Optimal Manual Restoration (OMR) command (ComOmr ) can be found under the Optimal Power Restoration toolbar (click on the Change Toolbox icon ( ) of the main toolbar). The OMR command dialogue is shown by clicking on the Optimal Manual Restoration icon ( ). The OMR calculation determines the optimal sequence for operating manual switches when searching for location of a fault in a distribution network. This tool is intended for distribution networks with a radial feeder topology which may contain remote control switches (RCS). The Optimal Manual Restoration tool defines the locations of manual switches which are to be opened/closed and the corresponding sequential order that a service team should open/close these switches in order to restore power safely to the greatest number of consumers in the shortest possible time. The sequential order is defined by OMR levels: level 1 corresponds to the first step in the OMR process, level 2 corresponds to the second step and finally level 3 to the last one. In this section the term switch refers to a coupler element ElmCoup or a switch element StaSwitch. The concept of feeder pockets is used in the calculation. A pocket represents an enclosed area of the radial DIgSILENT PowerFactory 15, User Manual

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CHAPTER 31. OPTIMAL POWER RESTORATION network delimited by a remote control switch, open manual switches or a calculated OMR terminal. The OMR calculation determines one OMR terminal per level for each pocket. All manually closed switches connected to the OMR terminal are considered to have the same OMR level equivalent to the level for which the OMR terminal has been assigned. Up to three OMR levels can be calculated i.e. Level 1, Level 2 and Level 3. Level 1 pockets are areas enclosed by remote control switches and open manual switches. Level II pockets are areas enclosed by remote control switches, open manual switches and OMR level I switches. Similarly, Level 3 pockets are areas enclosed by remote control switches, open manual switches and OMR switches of level 1 and 2.

31.4.1

OMR Calculation Prerequisites

The following network configuration conditions are required by the Optimal Manual Restoration calculation: • A balanced Load Flow calculation must be available. • The network must contain at least one defined feeder element ElmFeeder. • Only radial networks will be processed. The option “Feeder is supposed to be operated radially" available in the feeder’s Basic Data page must be selected for the relevant feeders. • It is recommended that a Backbone calculation is first performed (see Section 35.5). • There must be at least one remote control switch in the network. • It is recommended to build the network using terminals or secondary substation layouts (ElmTrfstat).

31.4.2

Basic Options Page

The Basic Options page of the OMR calculation tool is shown in Figure 31.4.1.

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Figure 31.4.1: Basic Options Page of the OMR Calculation Tool

Determine ’OMR’ for In this field the user must specify either All Feeders or Selected Feeders. If Selected Feeders option is chosen then a user-defined set (SetSelect) of feeders can be defined for the OMR calculation. Max. Number of ’OMR’ Levels The maximum number of OMR levels can be set in this field with values between 1 and 3. All OMR levels higher than this setting will not be calculated. Min. Power in Pocket The minimum consumption (sum of all load elements within a pocket) below which a delimited area will not be considered as a pocket for the purposes of the calculation. This value applies to all OMR levels. Backbone Order (Max.) If a number of network backbones exist (e.g. following a Backbone calculation), the Backbone Order (Max.) option defines the number of backbones to be considered for calculation (ordered according to parameter e:cBbOrder of the backbone element ElmBbone). The elements contained within a backbones of an order higher than this value will be considered as part of a non-backbone branch. Show BackBones button The button Show BackBones provides access to the calculation relevant backbones. The Backbone Order (Max.) option must be higher or equal than 1 in order to for at least one calculation relevant backbone to be shown. Show Output The Show Output checkbox enables the display of a calculation report in the Output Window.

31.4.3

Advanced Options Page

The Advanced Options page of the OMR calculation tool is shown in Figure 31.4.2. DIgSILENT PowerFactory 15, User Manual

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Figure 31.4.2: Advanced Options Page of the OMR Calculation Tool

Penalty Factor Penalty factors for switches depend on branch type and the level for which the OMR is being calculated. Two settings are available for introducing penalty factors: Branches end at Manual Switch (default value: 20%) and Non-Backbone Branches (Level 1) (default value: 25%). The default values are are referred to below to illustrate their practical usage. Penalty factors are used differently depending on the OMR level being calculated: • OMR level 1: – Switches located in backbone branches which end only with an RCS - no penalty is applied, weighting factor is 1.0. – Switches located in backbone branches which end only with a manual switch - 20% penalty factor is applied, weighting factor is 0.8. – Switches located in non-backbone branches which end only with an RCS - 25% penalty factor is applied, weighting factor is 0.75. – Switches located in non-backbone branches which end only with an open manual switch 20% and 25% penalty factors are applied resulting to a weighting factor of 0.6. – Switches located in non-backbone branches which end with an open RCS and an open manual switch - 25% penalty factor is applied, weighting factor is 0.75. • OMR level 2 and 3: – Switches located in backbone branches which end with an open RCS - No penalty is applied, weighting factor is 1.0. – Switches located in backbone branches which end with an open manual switch - 20% penalty factor is applied, weighting factor is 0.8. – Switches located in non-backbone branches which end with an open RCS - no penalty is applied, weighting factor is 1.0. 728

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31.4. OPTIMAL MANUAL RESTORATION – Switches located in non-backbone branches which end with an open RCS and an open manual switch - no penalty is applied, weighting factor is 1.0. – Switches located in non-backbone branches which end with an open manual switch - 20% penalty factor is applied, weighting factor is 0.8. The term network branches is used for applying penalty factors. Branches are network paths starting from the feeder’s starting terminal and ending at a final downstream element (a radial topology is always assumed). For this purpose, branches are categorised according to the following criteria: • Branches that end with an open manual switch that cannot be activated (parameter e:iResDir of the switch element is set to “Do not use for power restoration"): Inaccessible (geographical limitation, old technology etc...). These branches are not used in the OMR calculation. • Branches that end with an open manual switch that can be activated. For these branches the manual restoration from the same feeder applies. • Branches that end with a load element (does not lead to an open switch). These branches are not used in the OMR calculation. • Branches that end with an open remote control switch that cannot be activated. These types of branches are not considered to lead to an open manual switch. • Branches that end with an open remote control switch that can be activated. For these branches the remote control restoration from same feeder applies. • Branches that end (within selected backbones) with an open remote control switch that can be activated. These branches are considered as a tie open point restoration from another feeder. Load Flow A link to the Load Flow calculation settings is available by clicking on the blue arrow pointing to the right of the Load Flow field. The balanced Load Flow calculation type is automatically chosen (Unbalanced and DC Load Flow options are not supported).

31.4.4

Definition of the objective function

The scope of the OMR calculation is to minimize the following objective function: 𝑥 𝑥 𝑥 𝑥 ∆𝑥 = |𝑃𝑢𝑝𝑅𝑒𝑔 · 𝐹𝑢𝑝𝑅𝑒𝑔 − 𝑃𝑑𝑜𝑤𝑛𝑅𝑒𝑔 · 𝐹𝑑𝑜𝑤𝑛𝑅𝑒𝑔 |

The members of the above objective function are defined based on the following equalities: ∑︁ 𝑢𝑝𝑁 𝑆𝑡𝑎𝑟𝑡 𝑥 𝑥 𝑠𝑡𝑎𝑟𝑡𝑅𝑒𝑔 𝑃𝑢𝑝𝑅𝑒𝑔 = 𝑃𝑢𝑝 − 𝑃𝑢𝑝 − 𝑃𝑑𝑜𝑤𝑛 ∑︁ 𝑢𝑝𝑁 𝑆𝑡𝑎𝑟𝑡 𝑥 𝑥 𝑠𝑡𝑎𝑟𝑡𝑅𝑒𝑔 𝐹𝑢𝑝𝑅𝑒𝑔 = 𝐹𝑢𝑝 − 𝐹𝑢𝑝 − 𝐹𝑑𝑜𝑤𝑛 ∑︁ 𝑥 𝑥 𝑑𝑜𝑤𝑛𝑁 𝑆𝑡𝑎𝑟𝑡 𝑃𝑑𝑜𝑤𝑛𝑅𝑒𝑔 = 𝑃𝑑𝑜𝑤𝑛 − 𝑃𝑑𝑜𝑤𝑛 ∑︁ 𝑥 𝑥 𝑑𝑜𝑤𝑛𝑁 𝑆𝑡𝑎𝑟𝑡 𝐹𝑑𝑜𝑤𝑛𝑅𝑒𝑔 = 𝐹𝑑𝑜𝑤𝑛 − 𝐹𝑑𝑜𝑤𝑛

(31.1)

(31.2) (31.3) (31.4) (31.5) (31.6)

where: • 𝑥 is the terminal of the calculated pocket, 𝑥 • 𝑃𝑢𝑝𝑅𝑒𝑔 is the upstream active power at terminal 𝑥 with reference to the corresponding pocket, 𝑥 • 𝑃𝑑𝑜𝑤𝑛𝑅𝑒𝑔 is the downstream active power at terminal 𝑥 with reference to the corresponding pocket,

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CHAPTER 31. OPTIMAL POWER RESTORATION 𝑥 • 𝐹𝑢𝑝𝑅𝑒𝑔 is the upstream forced outage rate (FOR) at terminal 𝑥 with reference to the corresponding pocket, 𝑥 • 𝐹𝑑𝑜𝑤𝑛𝑅𝑒𝑔 is the downstream forced outage rate (FOR) at terminal 𝑥 with reference to the corresponding pocket, 𝑥 • 𝑃𝑢𝑝 is the upstream active power at terminal 𝑥 with reference to corresponding feeder, 𝑠𝑡𝑎𝑟𝑡𝑅𝑒𝑔 • 𝑃𝑢𝑝 is the upstream active power at the corresponding pocket starting element with reference to feeder, 𝑢𝑝𝑁 𝑆𝑡𝑎𝑟𝑡 • 𝑃𝑑𝑜𝑤𝑛 is the downstream active power of neighbouring pocket’s (upstream with respect to terminal 𝑥) starting element with reference to feeder, 𝑥 • 𝐹𝑢𝑝 is the upstream FOR at terminal 𝑥 with reference to corresponding feeder, 𝑠𝑡𝑎𝑟𝑡𝑅𝑒𝑔 • 𝐹𝑢𝑝 is the upstream FOR at corresponding pocket’s starting element with reference to feeder, 𝑢𝑝𝑁 𝑆𝑡𝑎𝑟𝑡 • 𝐹𝑑𝑜𝑤𝑛 is the downstream FOR of neighbour pocket’s (upstream with respect to terminal 𝑥) starting element with reference to feeder, 𝑥 • 𝑃𝑑𝑜𝑤𝑛 is the downstream active power at terminal 𝑥 with reference to corresponding feeder, 𝑑𝑜𝑤𝑛𝑁 𝑆𝑡𝑎𝑟𝑡 • 𝑃𝑑𝑜𝑤𝑛 is the downstream active power of neighbour pocket’s (downstream with respect to terminal 𝑥) starting element with reference to feeder, 𝑥 • 𝐹𝑑𝑜𝑤𝑛 is the downstream FOR at terminal 𝑥 with reference to corresponding feeder and 𝑑𝑜𝑤𝑛𝑁 𝑆𝑡𝑎𝑟𝑡 • 𝐹𝑑𝑜𝑤𝑛 is the downstream FOR of neighbour pockets (downstream with respect to terminal 𝑥) starting element with reference to feeder.

A manual switch is considered as being an OMR switch of a certain level if its associated terminal ∆𝑥 objective function is minimum compared with the objective functions of the other terminals within the calculated pocket.

31.4.5

Example of an Optimal Manual Restoration Calculation

An example of the use of the Optimal Manual Restoration tool is shown here. Consider the MV distribution network (20 kV) as displayed in Figure 31.4.3. Five feeders are defined, one main feeder (Feeder A) supplies power in normal operation to the displayed network. Feeder A is radially operated and containing a number of normally opened switches. Several remotely controlled switches are also defined and their associated substation is marked with a green circle.

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Figure 31.4.3: Generic MV Distribution Network

A substation layout similar to the one shown in Figure 31.4.4 is used for all substations.

Figure 31.4.4: Generic Substation Single Line Diagram

A backbone calculation (ComBbone) for Feeder A is performed on this network based on path load (see Section 35.5 for details of how to run the Backbone Calculation), thus obtaining four backbones (from main Feeder A to the other four) as shown in Figure 31.4.5.

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Figure 31.4.5: Backbone Search Calculation for the Given MV Network

Using the backbone information an OMR calculation may be performed with reference to main Feeder A. The OMR calculation automatically updates the single line diagram with specific colors for the different OMR levels for each switch and associated substation as in Figure 31.4.6.

Figure 31.4.6: OMR Calculation Results Shown in the Single Line Diagram using Different Colors

If the Show Output checkbox is enabled in the Basic Data page of the OMR command dialogue then a list of all the switches and their associated OMR level will be printed to the Output Window. 732

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Chapter 32

Generation Adequacy Analysis 32.1

Introduction

The ability of the power system to be able to supply system load under all possible load conditions is known as System Adequacy. Specifically this relates to the ability of the generation to meet the system demand while also considering typical system constraints such as: • Generation unavailability due to fault or maintenance requirements; • Variation in system load on an monthly, hourly and minute by minute basis; • Variations in renewable output (notably wind generation output), which in turn affects the available generation capacity. The PowerFactory Generation Adequacy Tool is designed specifically for testing of System Adequacy. Using this tool, it is possible to determine the contribution of wind generation to overall system capacity and to determine the probability of Loss of Load (LOLP) and the Expected Demand Not Supplied (EDNS). Note: The Generation Adequacy Assessment is completed using the Monte Carlo Method (probabilistic)

32.2

Technical Background

The analytical assessment of Generation Adequacy requires that each generator in the system is assigned a number of probabilistic states which determine the likelihood of a generator operating at various output levels. Likewise, each of the system loads can be assigned a time based characteristic that determines the actual system load level for any point of time. A simplified general illustration of the Generation Adequacy assessment is shown in Figure 32.2.1. In such a small example, it is possible to determine the Generation Adequacy analytically in a relatively short time. However, as the number of generators, generator states, loads and load states increases, the degrees of freedom for the analysis rapidly expands so that it becomes impossible to solve in a reasonable amount of time. Such a problem is ideally suited to Monte Carlo simulation.

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Figure 32.2.1: Generation Adequacy Assessment Illustration

Monte Carlo Method In the Monte Carlo method, a sampling simulation is performed. Using uniform random number sequences, a random system state is generated. This system state consists of random generating operating states and of random time points. The generating operating states will have a corresponding generation power output, whereas the time points will have a corresponding power demand. The value of Demand Not Supplied (DNS) is then calculated for such state. This process is done for a specific number of draws (iterations). At the end of the simulation, the values of the Loss of Load Probability (LOLP), Loss of Load Expectancy (LOLE), Expected Demand Not Supplied (EDNS), and Loss of Energy Expectancy (LOEE) indices are calculated as average values from all the iterations performed. Pseudo Random Number Generator A Monte Carlo simulation relies on the generation of random numbers of “high" quality. As all computers run deterministic code to generate random numbers, a software random number generator is known as a pseudo random number generator (PRNG). There are various PRNGs available, some of which do not display appropriate statistical qualities for use in Monte Carlo simulations, where very long sequences of independent random numbers are required. PowerFactory uses an implementation of the ’RANROT’ PRNG. This generator displays excellent statistical qualities suitable for Monte Carlo simulations and is also relatively fast. Example To illustrate the process of a Monte Carlo simulation, an example is now presented using Figure 32.2.1 734

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32.2. TECHNICAL BACKGROUND as the example network. For each iteration, the operating state for each generator is randomly selected by generating a uniform random number. For each of these states, the corresponding power output of the generator is calculated. The total generation power of the system is calculated by summing all the generator outputs. For the same iteration, a time point in the system is randomly selected. For this time point, the power demand of each load is obtained. The total demand of the system is calculated by summing all the load demands. It is then possible to obtain the ’Demand Not Supplied’ (DNS) value for this iteration, where DNS is defined as shown in Equation (32.1).

𝐷𝑁 𝑆 =

∑︁

𝐷𝑒𝑚𝑎𝑛𝑑 −

∑︁

(32.1)

𝐺𝑒𝑛𝑒𝑟𝑎𝑡𝑖𝑜𝑛

For example, in the first iteration, the generator states might be G1: 100%, G2: 100%, and G3: 75%. The corresponding outputs would be then G1: 100 MW, G2: 60 MW, and G3: 60 MW. The total generation output is the sum of all the three generator outputs; 220 MW. Also, a random time point yields Load A: 85 MW, Load B: 60 MW and Load C: 30 MW. The total system demand is the sum of all the load demands; 175 MW. Since the generation is greater than the demand, all the demand is supplied and the value of DNS is zero. In a second iteration, the generator states might be G1: 0%, G2: 75%, and G3: 75%. The corresponding outputs would be then G1: 0 MW, G2: 45 MW, and G3: 60 MW. The total generation output is now 105 MW. A second random time point yields say Load A: 60 MW, Load B: 50 MW, and Load C: 20 MW. The total system demand is now 130 MW. In this case, the generation is smaller than the demand, so there is demand that cannot be supplied. The demand not supplied is defined as the difference between demand and generation - 25 MW in this iteration. Continuing the analysis for a few subsequent iterations yields the results shown in Table 32.2.1: Draw 1 2 3 4 5 6

G1 MW 100 0 80 100 80 80

G2 MW 60 45 0 60 45 60

G3 MW 60 60 90 60 90 0

ΣG MW 220 105 170 220 215 140

Load A MW 85 60 110 40 60 90

Load B MW 60 50 35 50 40 50

Load C MW 30 20 10 15 20 5 Total

ΣD MW 175 130 155 105 120 145

DNS max(0, ΣD - ΣG) 0 25 0 0 0 5 30

DNS >0 No Yes No No No Yes 2

Table 32.2.1: Example Monte Carlo Analysis

Iteration six yields a second case where demand is not supplied. Once the analysis has continued in this way (usually for several tens of thousands of iterations) various indices of system adequacy can be calculated. The indices Loss of Load Probability (LOLP) and Expected Demand Not Supplied (EDNS) are the critical measures. They are calculated as follows:

𝐿𝑂𝐿𝑃 =

𝑁𝐷𝑁 𝑆 · 100% 𝑁

∑︀ 𝐸𝐷𝑁 𝑆 = DIgSILENT PowerFactory 15, User Manual

𝐷𝑁 𝑆 𝑁

(32.2)

(32.3) 735

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𝐿𝑂𝐿𝑃 =

2 · 100 = 33, 33% 6

(32.4)

30 = 5𝑀 𝑊 6

(32.5)

𝐸𝐷𝑁 𝑆 =

32.3

Database Objects and Models

There are several database objects in PowerFactory specifically related to the ’Generation Adequacy’ Analysis, such as: • Stochastic Model for Generation Object (StoGen); • Power Curve Type (TypPowercurve); and • Meteorological Station. This section provides information about each of these objects.

32.3.1

Stochastic Model for Generation Object (StoGen)

This object is used for defining the availability states of a generator, an example of which is shown in Figure 32.3.1. An unlimited number of states is possible with each state divided into: • Availability of Generation (in %) • Probability of Occurrence (in %) This means that for each state, the total available generation capacity in % of maximum output must be specified along with the probability that this availability occurs. Note that probability column is automatically constrained, so that the sum of the probability of all states must equal 100 %.

Figure 32.3.1: Stochastic Model for Generation Dialogue Box

The Stochastic model for generation object should reside within the project library, Equipment Type Library. 736

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32.3. DATABASE OBJECTS AND MODELS Note that the generator maximum output is calculated as 𝑆𝑛𝑜𝑚 ·cos 𝜃 where 𝑆𝑛𝑜𝑚 is the nominal apparent power and cos 𝜃 is the nominal power factor.

32.3.2

Power Curve Type (TypPowercurve)

This object is used to specify the wind speed (in m/s) vs nominal power output (p.u or MW) for wind turbine generators. The dialogue for the curve is shown in Figure 32.3.2.

Figure 32.3.2: Power Curve Type (TypPowercurve)

For wind-speed values between specified curve values, PowerFactory interpolates using the method specified in the Approximation drop down menu. Interpolation options include: • constant • linear • polynomial • spline and • hermite. To change the Power unit, go to the configuration tab and choose either p.u or MW by selecting the appropriate radio button.

32.3.3

Meteorological Station (ElmMeteostat)

It is often the case that groups of wind generators have a wind speed characteristic that is correlated. PowerFactory can represent such a correlation through the Meteo Station Object. This object is a grouping element and is located within the project Network Data as shown in Figure 32.3.3.

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Figure 32.3.3: Project Data Structure showing the location of the ’Meteo Station’ Object

Note that when two wind generators are correlated as members of the same Meteo Station, they may still have different average wind speeds defined within their Generation Adequacy dialogue. During the Monte Carlo Analysis, a random wind speed is drawn for each Meteo Station. This wind speed is then applied to every wind generator in that Meteo Station using the Weibull Stochastic Model. Thus, the power is calculated according to the individual power curve of the generator. When the generator is using time characteristics as a wind model, then the correlation is given by the Monte Carlo drawn time, which is the same for all the generators of the system. Meteorological stations can be defined either via the element that is to be part of the meteorological station (from any of the generator elements described in Section 32.4), or via the single line diagram by right-clicking on an appropriate element and selecting DefineEˇ → Meteo Station (or Add toEˇ → Meteo Station) from the context-sensitive menu. Note that the ability to define a Meteo Station is dependent upon whether at least one of the ’member’ generators has the options Generator and Wind Generator selected on its Basic Data page. If these options are not selected, the context menu entry is not visible. Note: A graphical colouring mode exists for Meteorological Stations, so that they can be visualized in the single line graphic.

32.4

Assignment of Stochastic Model for Generation Object

For the Generation Adequacy Analysis, there is a distinction between Dispatchable (Conventional) Generation and Non-dispatchable Generation. Dispatchable generation refers to generation that can be controlled at a fixed output automatically, typically by varying the rate of fuel consumption. This includes generation technologies such as gas thermal, coal thermal, nuclear thermal and hydro. Non-dispatchable generation refers to generation that cannot be automatically controlled because the output depends on some non controllable environmental condition such as solar radiation or the wind speed. Wind turbine and solar photovoltaic generators are examples of such environmentally dependent generation technologies.

32.4.1

Definition of a Stochastic Multi-State Model

For both Dispatchable and Non-dispatchable generation it is possible to assign a Stochastic Multi-State model to define the availability of each unit. The availability is defined in a number of ’States’ each with a certain probability as described in Section 32.3.1. 738

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32.4. ASSIGNMENT OF STOCHASTIC MODEL FOR GENERATION OBJECT • Synchronous machine (ElmSym); • Static generator (ElmGenstat) set as Fuel Cell, HVDC Terminal, Reactive Power Compensation, Storage, or other Static Generator ; • Asynchronous machine (ElmAsm); and • Doubly-fed asynchronous machine (ElmAsmsc) In all cases, the stochastic model object is assigned on the elementŠs Generation Adequacy page, under Stochastic Multi-State Model. This is illustrated in Figure 32.4.1.

Figure 32.4.1: Generation Adequacy tab with a Stochastic Model for generation selected

Also, to consider the generation as dispatchable, the Wind Generation option in the Basic Data tab page of the synchronous, asynchronous, and doubly fed machine should be disabled. Definition of a Stochastic Model for Non-Dispatchable (Wind and Renewable) Generation As for the dispatchable generation, the following 3-phase models are capable of utilising the stochastic model for generation object, provided they are defined as generators and not as motors: • Synchronous machine (ElmSym) set as Wind Generator ; • Static generator (ElmGenstat) set as Wind Generator, Photovoltaic or Other Renewable • Asynchronous machine (ElmAsm) set as Wind Generator ; and • Doubly-fed asynchronous machine (ElmAsmsc) set as Wind Generator In all cases, the stochastic model object is assigned on the elementŠs Generation Adequacy tab page, under Stochastic Multi-State Model, as illustrated in Figure 32.4.1. Objects not considered in Generation Adequacy Analysis External Grids (ElmXnet), voltage and current sources (ElmVac, ElmIac) are ignored in the Generation Adequacy analysis.

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32.4.2

Stochastic Wind Model

In addition to the stochastic multi-state model for generation described above, a stochastic wind model may be defined on the element’s Generation Adequacy page (provided that the type of generation is a wind generator). To enable this, navigate to the Generation Adequacy tab and check the option Wind Model. The page will appear as shown in Figure 32.4.2.

Figure 32.4.2: Stochastic Wind Model Definition

When the Stochastic Wind Model is selected, the wind generation characteristic is described using the Weibull Distribution. The mean wind speed, and shape factor (Beta) of the distribution can be adjusted to achieve the desired wind characteristic for each wind generator. In addition to describing the Weibull distribution using Mean Wind Speed and Beta, the following alternate methods of data input can be used: • Mean Wind Speed and Variance; • Lambda and Variance; • Lambda and Beta. The input method can be changed by using the input selection arrow method from the input window that appears.

32.4.3

and choosing the desired

Time Series Characteristic for Wind Generation

If detailed data of wind generation output over time or wind speed over time is available, then this can be used instead of a Stochastic Model. The data can be read by PowerFactory as either a ChaVec characteristic or from an external file using the ChaVecFile characteristic. In both cases the information required is one year of data in hourly intervals - although non integer values can also be specified in the referenced data. 740

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32.4. ASSIGNMENT OF STOCHASTIC MODEL FOR GENERATION OBJECT If the option Time Series Characteristics of Wind Speed is selected, then the actual wind generator power output for each iteration is calculated automatically from the Wind Power Curve. If the option, Time Series Characteristic of Active Power Contribution is selected then no power curve is required. Data for multiple years can also be used by referencing an additional characteristic for each year. The Generation Adequacy algorithm then selects a random wind speed or power value from one of the input data years - essentially there is more data for the random Monte Carlo iteration to select from. A screenshot showing a wind generator model with three years of data is shown in Figure 32.4.3.

Figure 32.4.3: Wind Model using Wind Output Data

Other Renewable Generation Static Generators (ElmGenstat) of category Photovoltaic or Other Renewable cannot have a Stochastic wind model definition. However, they may still have a Stochastic Multi-State model. Their output is added to the aggregated non-dispatchable generation as described later in this chapter. Consideration of Parallel Machines The Generation Adequacy analysis automatically considers parallel machines defined in the basic data of the generator object using the variable (ngnum), as shown in Figure 32.4.4. Each of the parallel machines is treated independently. For example, a random operational state is generated for each of the parallel machines. Effectively this is the same as if n machines were modelled separately.

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Figure 32.4.4: Synchronous machine element with the parameter ngnum (number of parallel machines highlighted).

32.4.4

Demand definition

Unless a time characteristic is assigned to either the Active Power (plini) or Scale factor (scale0) variables (highlighted in Figure 32.4.5) of the load element, then the load is treated as fixed demand. This means that the demand value does not change during the entire analysis. Both General Loads (ElmLod) and LV Loads (ElmLodlv ) are considered for the analysis.

Figure 32.4.5: ElmLod object dialogue showing the variables that can have applied time Characteristics effecting the Generation Adequacy analysis.

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32.4. ASSIGNMENT OF STOCHASTIC MODEL FOR GENERATION OBJECT More information about assigning time based characteristics to object variables can be found in Chapter 16: Parameter Characteristics, Load States, and Tariffs.

32.4.5

Generation Adequacy Analysis Toolbar

The selection of the Generation Adequacy toolbar is shown in Figure 32.4.6.

Figure 32.4.6: Generation Adequacy Toolbar selection

Once selected, the available buttons are shown in Figure 32.4.7.

Figure 32.4.7: Generation Adequacy Analysis Toolbar

32.4.6

Generation Adequacy Initialisation Command (ComGenrelinc)

Before a Generation Adequacy Analysis can be completed, the simulation must be initialised. The Initialisation dialogue box with the Basic Options tab selected is shown in Figure 32.4.8. The available options are explained in this section.

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Figure 32.4.8: Generation Adequacy Initialisation Command

Network • System Losses; Here a fixed percentage of losses can be entered. This value is subtracted from the total generation at each iteration. • Load Flow Command; This is a reference to the load-flow command that will be used to obtain the network topology for the analysis. It must be set to AC load-flow balanced, positive sequence or DC load-flow. A converging load-flow is a requirement for the Generation Adequacy analysis. Demand Consideration • Fixed Demand Level; If this option is selected, all load time characteristics are ignored and the total demand is calculated at the initial iteration and used for all subsequent iterations. • Consider Time Characteristics; If this option is selected, any time characteristics assigned to loads will be automatically considered in the calculation. Therefore, the total demand can vary at each iteration. 744

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32.4. ASSIGNMENT OF STOCHASTIC MODEL FOR GENERATION OBJECT Consider Maintenance Plans If this option is enabled then any maintenance plans (out of service or derating) in the project will be automatically considered. Consequently, when an iteration draws a time that falls within a planned outage or derating, the outage (or derating) is applied to the target element resulting in a reduction in available generation capacity. To define a maintenance plan, right-click the target object from the single line graphic or from the data manager and select the option Define... → Planned Outage For more information on Planned Outages refer to Chapter 12: Project Library, Section 12.3.5 (Planned Outages). Consider Maintenance Plans • Year of Study; The period considered for the Generation Adequacy analysis is always one year. However, it is possible for load characteristics to contain information for many years. Therefore, the year considered by the calculation must be selected. Note that this variable does not influence the wind speed or wind power data if the wind model for the generator references time series data as described in Section 32.4.3 (Time Series Characteristic for Wind Generation). If more than one yearŠs data is available, this simply increases the pool of available data for the analysis. • Months, Days; These checkboxes allow the user to select the time period that will be considered for the analysis. For instance, if only January is selected then the iteration time will be constrained to within this month. Time Intervals The user can specify up to three time intervals for the time window in which the analysis will be completed. The time interval starts at the From hour (0 minutes, 0 seconds), and ends at the To hour (0 minutes, 0 seconds) inclusive. Output options The output window of the Generation Adequacy Initialisation Command is shown in Figure 32.4.9.

Figure 32.4.9: Output options for the Generation Adequacy Initialisation

• Create Plots; If this option is checked, then PowerFactory will automatically create output plots after the simulation finishes. See Section 32.5 for details of the plots that are automatically created. Note this will generate a new set of plots for each run of the analysis. So, if you wish for an existing set of plots to be updated, then leave this option unchecked. • Draws; If this option is checked, then the user can specify a location for the results of the simulation to be permanently stored within the database. This is the result of each iteration. If this option is unchecked, then the results are deleted after each simulation run. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 32. GENERATION ADEQUACY ANALYSIS • Distribution; Here the user can select the storage location for the distribution probabilities for the entire analysis. This information is always retained in the database. Advanced Options The Advanced Options screen is shown in Figure 32.4.10. Here the user can change the option for the generation of random numbers from auto to renew. If the renew option is selected, then the simulation can use one of a number of pre-defined random seeds (A-K). As the software ’pseudo-random’ number generator is deterministic, this allows for the exact sequence of random numbers to be repeated.

Figure 32.4.10: Initialisation Command Advanced Options

32.4.7

Run Generation Adequacy Command (ComGenrel)

The Run Generation Adequacy Analysis Command appears in two styles depending on the status of the calculation. If the calculation is being run for the first time, then it appears as shown in Figure 32.4.11. On the other hand, if some iterations are already complete, then the calculation can be continued and the dialogue appears as shown in Figure 32.4.12.

Figure 32.4.11: Run Generation Adequacy Command Dialogue (new simulation)

Figure 32.4.12: Run Generation Adequacy Command Dialogue (post simulation)

Pressing Execute will run the Generation Adequacy Analysis. The button 746

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32.5. GENERATION ADEQUACY RESULTS the analysis before the set number of iterations is complete, if desired. Later, the simulation can be resumed from the stop point using the Run Generation Adequacy Analysis Command. Max Number of Iterations This specifies the number of iterations to be completed by the Monte Carlo Analysis. The default setting is 100,000. Additional Iterations After one analysis is completed, the Generation Adequacy Analysis can be extended for a number of Additional Iterations. Especially in very large systems, it may be useful to run the first simulation with a smaller number of initial iterations, say 20,000 and then run additional iterations as necessary using this option. Generation Adequacy This reference provides a link to the Generation Adequacy Initialisation Command, so that the calculation settings can be easily inspected.

32.5

Generation Adequacy Results

Result plots for the Generation Adequacy Analysis are automatically generated if the Create Plots option is enabled in Initialisation Command output options. Alternatively, the plots can be manually created using the toolbar plot icons

32.5.1

Draws (Iterations) Plots

This button ( ) draws by default four figures as shown in Figure 32.5.1. Each of the data points on the plots represents a single Monte Carlo simulation.

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Figure 32.5.1: Draws (Iterations) Plots

Figure A displays the following: • Total Available Capacity in MW; • Available Dispatchable Generation in MW; • Total Demand in MW; Figure B displays the following: • Available Non-dispatchable capacity in MW; Figure C displays the following:: • Total Reserve Generation Capacity in MW; Figure D displays the following:: • Total Demand in MW; • Residual Demand in MW;

32.5.2

Distribution (Cumulative Probability) Plots

This button ( ) draws a distribution plot which is essentially the data from ’Draws’ plots sorted in descending order. The data then becomes a cumulative probability distribution. An example is shown 748

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32.5. GENERATION ADEQUACY RESULTS in Figure 32.5.2.

Figure 32.5.2: Distribution (Cumulative Probability) Plots

Obtaining the LOLP from the Distribution Plots The LOLP index can be obtained by inspection directly from the Distribution Plots if the demand is constant. The LOLP can be read directly from the intersection of the Total Generation curve and the Total Demand curve as demonstrated in Figure 32.5.3. When the demand is variable, then the LOLP index cannot be inferred from the above diagram. Figure 32.5.4 shows such a case. There is no intersection point even though the calculated LOLP index in this case is 20 %. In such cases, the LOLP index must be inferred from the distribution plot of the Total Reserve Generation. As shown in Figure 32.5.5, the intersection of this curve with the x-axis gives the LOLP index.

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Figure 32.5.3: Inferring the LOLP index directly from the intersection of the Total Generation and Total Demand

Figure 32.5.4: Variable Demand - distribution of Total Generation and Total Demand

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Figure 32.5.5: Total Reserve Generation

32.5.3

Convergence Plots

This button ( ) creates the so-called convergence plots for the LOLP and EDNS. As the number of iterations becomes large the LOLP index will converge towards its final value, likewise for the EDNS. The convergence plots are a way of visualising this process. An example convergence plot is shown in Figure 32.5.6.

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Figure 32.5.6: Example Convergence Plot Note: By default, the convergence plot is zoomed to the plot extent and due to the number of iterations it may be difficult to observe the upper and lower confidence limits. It is suggested that the ’Zoom Y-axis’ and ’Zoom X-axis’ buttons are used to observe the confidence limits in greater detail.

On both plots, the upper and lower confidence intervals are also drawn. The sample variance is calculated as follows:

𝜎2 =

𝑛 ∑︁ 1 · (𝑦𝑖 − 𝑦¯)2 𝑛 − 1 𝑖=1

(32.6)

where 𝑛 is the number of samples,𝑦𝑖 is the sample and 𝑦¯ is the sample mean. The 90 % confidence interval is calculated according to the following formula:

𝜎 𝐶𝐿 = 𝑦¯ ± √ · 𝑧 𝑛

(32.7)

where z is the standard inverse probability for the Student’s t distribution with a confidence interval of 90 %. Note z tends to 1.645 (inverse normal) as the number of iterations becomes large.

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32.5.4

Summary of variables calculated during the Generation Adequacy Analysis Name Available patchable Capacity

Internal Name Disc:AvailDCap

Available NonDispatchable Capacity

c:AvailNDCap

Total Available Capacity

c:AvailTotcap

Total Demand

c:DemTot

Demand Supplied Demand Not Supplied Total reserve Generation Reserve Dispatchable generation Used NonDispatchable Generation Used Dispatchable Generation Total Used generation Residual Demand

c:DemS

Description The sum of dispatchable capacity at each iteration after the consideration of the availability states The sum of non-dispatchable capacity at each iteration after the consideration of the availability states and also the stochastic/time models for wind generation c:AvailNDCap + c:AvailDCap Total Demand considering any time based characteristics min(C:DemTot, c:AvailTotcap * (1 Losses% / 100)

c:DNS

c:DemTot - DemS

c:ResvTotGen

c:AvailTotCap - c:DemTot * (1 + Losses% / 100)

c:ResDGen

c:AvailDCap - c:DemTot Losses% / 100)

c:NDGen

min(C:AvailNDCap, DemTot * (1 + Losses% / 100))

c:DGen

min(C:AvailDCap, DemTot * (1 + Losses% / 100) - c:NDGen)

c:TotGen

c:Dgen + c:NDGen

c:ResidDem

c:DemTot * (1+ Losses% / 100) c:NDGen

*

(1

+

Table 32.5.1: Generation Adequacy Calculated Variables

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Chapter 33

Optimal Power Flow 33.1

Introduction

The Optimal Power Flow (OPF) module in PowerFactory optimizes a certain objective function in a network whilst fulfilling equality constraints (the load flow equations) and inequality constraints (i.e. generator reactive power limits). The user can choose between interior point and linear optimization methods. In the case of linear optimization, contingency constraints can also be enforced within OPF. An OPF calculation in PowerFactory can be initiated by one of the following means: • By going to the main menu and selecting Calculation → Optimal Power Flow...; or • By selecting “Additional Tools" from the Change Toolbox button ( icon .

)and then click on the OPF

In both cases, the calculation is started by pressing the Execute button in the OPF command dialogue.

33.2

AC Optimization (Interior Point Method)

If the AC Optimization method is selected, the OPF performs a non-linear optimization based on a state-of-the-art interior point algorithm. The following sections explain the selection of objective function to be optimized, the selection of control variables, and the definition of inequality constraints. The OPF command in PowerFactory is accessible by going to the main menu and selecting Calculation → Optimal Power Flow..., or via the OPF icon on the main toolbar.

33.2.1

Basic Options

The Basic Options page of the OPF dialogue (AC optimization method) is shown in Figure 33.2.1.

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Figure 33.2.1: Basic Options page of OPF Dialogue (AC Optimization Method)

33.2.1.1

Method

To perform an AC optimization OPF study, the Method must be set to AC Optimization (Interior Point Method) as shown in Figure 33.2.1.

33.2.1.2

Objective Function

The OPF command dialogue, configured for AC optimization, has a selection of three distinct objective functions. These are: • Minimization of Losses • Minimization of Costs • Minimization of Load Shedding Minimization of Losses When this objective function is selected, the goal of the optimization is to find a power dispatch which minimizes the overall active power losses. Minimization of Costs When this objective function is selected, the goal of the optimization is to supply the system under optimal operating costs. More specifically, the aim is to minimize the cost of power dispatch based on non-linear operating cost functions for each generator and on tariff systems for each external grid. For this purpose, the user needs to introduce for each generator, a cost function for its power dispatch; and for each external grid, a tariff system.

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33.2. AC OPTIMIZATION (INTERIOR POINT METHOD) Cost Functions for Generators Imposing an operating cost function on a generator element is done as follows: on the Optimal Load Flow page of each synchronous machine (ElmSym) element’s dialogue (see Figure 33.2.2), it is possible to specify the operating costs of the unit with the aid of the Operating Costs table (which relates active power produced (in MW) to the corresponding cost (in $/h)). This data is then represented graphically beneath the Operating Costs table, for verification purposes (see Figure 33.2.2). The number of rows that can be entered in to the table is unlimited. To add or delete table rows, right-click on a row number in the table and select the appropriate command (i.e. Copy, Paste, Select All; Insert Rows, Append Rows, Append n Rows, Delete Rows, etc.). If there are more than two rows, spline interpolation is used. Tariff Systems for External Grids An external grid contributes to the overall cost function by a predefined tariff system. On the Optimal Load Flow page of each external grid (ElmXnet) element’s dialogue (see Figure 33.2.3), the tariffs can be edited via the Incremental Costs table. This table relates the cost (in $/MWh) over a certain range of active power exchange. The input data is represented graphically beneath the Incremental Costs table. In addition, the user can enter a monthly no load cost (in $/month), which can be interpreted as a vertical shift of the cost function (see Figure 33.2.3). In contrast to a synchronous machine, where the cost curve is directly expressed in $/h, the cost curve of an external grid is defined by means of a tariff which holds within certain intervals. Mathematically speaking, the cost curve of a synchronous machine is calculated as the interpolation of predefined cost points, whereas the cost curve of an external grid is a piecewise linear function with predefined slopes in each interval.

Figure 33.2.2: Editing the Operating Costs of a Synchronous Machine (ElmSym)

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Figure 33.2.3: Editing the Incremental Costs of an External Net (ElmXnet)

Note that this piecewise linear function is not differentiable at the interval limits. Since non-differentiable functions might cause problems within the optimization routine, PowerFactory smooths the cost function slightly over a small range around the non-differentiable points. The width of this range can be defined by the user through the Smoothing of Cost Function factor (also shown in Figure 33.2.3). A value of 0% corresponds to no smoothing of the curve, whereas a value of 100% corresponds to full interpolation. The default value is 5%. It is recommended to leave this value at its default setting. Minimization of Load Shedding The goal of this objective function is to minimize the overall cost of load shedding, such that all conˇ For straints can be fulfilled. A typical application for this objective function is SInfeasibility ¸ HandlingT. the abovementioned objective functions, it may occur that the constraints imposed on the network are such that no feasible solution exists. This is evidenced by a lack of convergence of the optimization. In such cases, it is highly likely that not all loads can be supplied due to constraint restrictions. Hence it is recommended in these situations to firstly perform a Minimization of Load Shedding. In this (and only this) optimization scenario, all load elements which have the option Allow load shedding enabled will act as controls. This option is enabled in the load (ElmLod) elementŠs dialogue on the Optimal Load Flow page in the Controls section. All loads without this option enabled will behave as they would in a conventional load flow calculation. In order to minimize the overall load shedding, for each individual load, the user must specify the cost of shedding (in $ per shed MVA). For each load that participates as a control in the optimization, the scaling factor will be optimized. The optimization is such that the overall cost of load shedding is minimized. Additionally, the user can specify the range over which the load may be scaled (options Min. load shedding and Max. load shedding), as shown in Figure 33.2.4.

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Figure 33.2.4: Editing a Load Element (ElmLod) for Minimization of Load Shedding

33.2.1.3

Controls

The global control parameters can be selected on the Basic Options page of the OPF dialogue. The user can specify which parameters might serve as potential degrees of freedom for the OPF algorithm; i.e. which parameters will contribute as controls. The set of potential controls can be grouped into four categories: 1. Generator Active Power Dispatch (ElmSym) 2. Generator Reactive Power Dispatch (ElmSym) 3. Transformer Tap Positions (for 2- and 3-winding transformers): • 2-Winding Transformer (ElmTr2): – Tap Position (continuous or discrete) • 3-Winding Transformer (ElmTr3): – HV-Tap Position (continuous or discrete) – LV-Tap Position (continuous or discrete) – MV-Tap Position (continuous or discrete) 4. Switchable Shunts (ElmShnt): • Number of steps (continuous or discrete) It should be noted that the load scaling factors will only be taken into account for the Minimization of Load Shedding objective function. In this case, all loads which allow load shedding are automatically used as controls. These global controls determine which element controls will be considered in the optimization. The general rule is as follows: a parameter will be considered as a control if the corresponding flag is set on the Optimal Load Flow page of the elementŠs dialogue and if, in addition, the corresponding global parameter is set on the Basic Options page of the OPF command dialogue (see Figure 33.2.5).

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CHAPTER 33. OPTIMAL POWER FLOW For example, if the control parameter Tap Position HV-Side of a 3-winding transformer is enabled (as shown in Figure 33.2.8), it will only be included in the OPF as a control parameter if the corresponding option Transformer Tap Positions is enabled in the OPF command dialogue (as shown in Figure 33.2.5). If enabled, the abovementioned control parameters serve as variable setpoints during the OPF. However, if a parameter is not enabled as a control parameter, the OPF will treat this parameter according to the load flow settings.

Figure 33.2.5: Global Controls for OPF (AC Optimization Method)

This could be a fixed position or a position found due to the option Automatic Tap Adjust of Transformers being selected in the load flow command. In this mode, the transformer tap position could be found in order to control the voltage of a certain node, or to be a slave that is externally controlled by some other transformer tap. Setting Individual Model-Based Controls Each control can be individually selected to take part in the optimization. Specifically, for each generator (ElmSym), each transformer (ElmTr2, ElmTr3), and each shunt (ElmShnt), the user can check the corresponding Controls flag on the optimization page of the elementŠs dialogue. Synchronous Machines A synchronous machine may contribute two possible setpoints, namely active and reactive power control (see Figure 33.2.6).

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Figure 33.2.6: Active and Reactive Power Controls of a Synchronous Machine (ElmSym)

2- and 3-Winding Transformers If a transformer has the Tap Position option selected, the user can further select the associated Control Mode to be used. This determines whether the tap position will be treated as a continuous or a discrete control parameter in OPF. Note that a 3-winding transformer has up to three tap changers which may individually be used as either continuous or discrete control parameters in OPF. Figure 33.2.7 shows the Controls section of the dialogue for a 2-winding transformer and Figure 33.2.8 shows the Controls section of the dialogue for a 3-winding transformer. It should be noted that the Optimize section with the selection of Pre- and post-fault position or Only pre-fault position are only considered by the DC OPF.

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Figure 33.2.7: Tap Position Control (and Loading Constraint) for a 2-Winding Transformer

Figure 33.2.8: Tap Position Control for a 3-Winding Transformer

Shunts In a similar fashion to transformers, the number of steps for a shunt may serve as either a continuous or a discrete optimization parameter (see Figure 33.2.9).

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Figure 33.2.9: Control Parameter for a Shunt(ElmShnt)

33.2.1.4

Constraints

The user can formulate various inequality constraints for certain system parameters, such that the OPF solution lies within these defined limits. Since all inequality constraints are considered as Shard ¸ ˇ setting constraints may result in no feasible solution being found. constraintsT, The handling of OPF constraints in PowerFactory is very flexible, and various categories of constraints exist. A constraint is considered in the OPF if and only if the individual constraint flag is checked in the element and the corresponding global flag is enabled in the OPF dialogue. Figure 33.2.10 shows the Constraints available for the AC optimization formulation of OPF in PowerFactory.

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Figure 33.2.10: Constraints Settings for OPF (AC Optimization Method)

The optimization uses further constraints that are automatically imposed as soon as the corresponding parameter is used as a control. Examples of such constraints are tap position limits and the number of steps for switchable shunts. Network elements and their available constraints are listed below: • Busbars and Terminals (ElmTerm): – Minimum Voltage – Maximum Voltage • Lines (ElmLne): – Maximum Loading • 2- and 3-Winding Transformer (ElmTr2, ElmTr3): – Maximum Loading – Tap Position range (if corresponding tap is a designated control parameter) • Shunts (ElmShnt): – Controller Steps range (if switchable steps are designated control parameters) • Generator (ElmSym): – Minimum Active Power – Maximum Active Power – Minimum Reactive Power – Maximum Reactive Power • Boundary (ElmBoundary ): 764

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33.2. AC OPTIMIZATION (INTERIOR POINT METHOD) – Minimum Active Boundary Flow – Maximum Active Boundary Flow – Minimum Reactive Boundary Flow – Maximum Reactive Boundary Flow Branch Flow Limits (max. loading) Branch flow limits formulate an upper bound on the loading of any branch (ElmLne, ElmTr2, ElmTr3, etc). The user has to specify a maximum value for the loading on the elementŠs Optimal Load Flow page (see Figure 33.2.11). If specified as shown in Figure 33.2.11, this constraint is only taken into consideration if the corresponding flag (Branch Flow Limits (max. loading)) in the OPF dialogue is also ticked. Loading limits are supported for lines and 2- and 3-winding transformers.

Figure 33.2.11: Max. Loading Constraint of a Line Element (similar for 2- and 3-Winding Transformers)

Active and Reactive Power Limits of Generators and External Grids For each synchronous machine (ElmSym) and external grid (ElmXnet), the user may impose up to four inequality constraints: namely a minimum and maximum value for active power generation; and a minimum and maximum value for reactive power generation (see Figure 33.2.12). Active power limits are specified as MW values; reactive power limits may be specified as either absolute values or as per unit values (i.e. referred to the typeŠs nominal apparent power). Alternatively, it is possible to directly use the reactive power limits specified in the synchronous machineŠs type (TypSym). Again, the user is free to select any number and combination of the available constraints.

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Figure 33.2.12: Active and Reactive Power Constraints of a Synchronous Machine (ElmSym)

Voltage Limits of Busbars/Terminals The maximum and minimum allowable voltages for each terminal or busbar element (ElmTerm) can be specified in the corresponding element’s dialogue (see Figure 33.2.13). Therefore, each terminal or busbar may contribute at most two inequality constraints to the OPF. Maximum and minimum voltage limits may be imposed individually; i.e. it is possible to specify an upper limit without specifying a lower limit.

Figure 33.2.13: Voltage Constraints for a Terminal/Busbar (ElmTerm)

Boundary Flow Limits

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33.2. AC OPTIMIZATION (INTERIOR POINT METHOD) PowerFactory boundary elements (ElmBoundary ), icon define topological regions in a power system by a user-specified topological cut through the network. Constraints can be defined for the flow of active and reactive power in a network (over a defined boundary or between internal and external regions of a boundary), and this constraint can then be enforced in OPF. For detailed information on defining boundaries, please refer to Chapter 13: Grouping Objects, Section 13.3.

Figure 33.2.14: Defining Boundary Flow Limits (ElmBoundary )

33.2.1.5

Mathematical Background

The non-linear optimization is implemented using an iterative interior-point algorithm based on the Newton-Lagrange method. Recall that the goal of the optimization is to minimize an objective function f subject to the equality constraints imposed by the load flow equations and also to the inequality constraints defined for various power system elements. This is summarised mathematically as follows: 𝑚𝑖𝑛 = 𝑓 (⃗𝑥) subject to: 𝑔(⃗𝑥) = 0 ℎ(⃗𝑥) ≤ 0 where g represents the load flow equations and h is the set of inequality constraints. Introducing a slack variable for each inequality constraint, this can be reformulated as: 𝑔(⃗𝑥) = 0 ℎ(⃗𝑥) + ⃗𝑠 = 0 ⃗𝑠 ≥ 0 We then incorporate logarithmic penalties and minimize the function: ∑︀ min = 𝑓 (⃗𝑥) − 𝜇 · 𝑖 𝑙𝑜𝑔(𝑠𝑖 ) where 𝜇 is the penalty weighting factor. In order to change the contribution of the penalty function: ∑︀ 𝑓𝑝𝑒𝑛 = 𝑖 𝑙𝑜𝑔(𝑠𝑖 ) to the overall minimization, the penalty weighting factor 𝜇 will be decreased from a user-defined initial value (𝜇𝑚𝑎𝑥 ) to a user-defined target value (𝜇𝑚𝑖𝑛 ). The smaller the minimum penalty weighting factor, the less the applied penalty will be for a solution which is close to the constraint limits. This may result in a solution that is close to the limiting constraint DIgSILENT PowerFactory 15, User Manual

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33.2.1.6

Results

The presentation of OPF results is integrated into the user interface, in that the OPF solution is available via the complete set of variables available for conventional load flow calculations. These can be viewed in the single line diagram or through a data browser. The inclusion of the following variables in the Flexible Data tab (for synchronous machines and grids) is suggested, as shown in Figure 33.2.15. The Variable Set must be set to ’Calculation Parameter’ as indicated below, and the actual variable names are given in parentheses. Synchronous machines: • Active Power (’Calculation Parameter’ 𝑃 : 𝑏𝑢𝑠1; this parameter is highlighted in Figure 33.2.15) • Reactive Power (’Calculation Parameter’ 𝑄 : 𝑏𝑢𝑠1) • Apparent Power (’Calculation Parameter’ 𝑆 : 𝑏𝑢𝑠1) • Voltage Magnitude (’Calculation Parameter’ 𝑢 : 𝑏𝑢𝑠1)

Figure 33.2.15: Definition of Flexible Data for Synchronous Machines (ElmSym)

Grids: • Total Production Cost, including costs through external grids (’Calculation Parameter’ c:cst_disp; see this parameter highlighted in Figure 33.2.16). It should be noted that the production costs are expressed in the same units utilized in the production cost tables of the individual generator elements. • Active Power Losses (Calculation Parameter 𝑐 : 𝐿𝑜𝑠𝑠𝑃 ) • Reactive Power Losses (Calculation Parameter 𝑐 : 𝐿𝑜𝑠𝑠𝑄) • Active Power Generation (Calculation Parameter 𝑐 : 𝐺𝑒𝑛𝑃 ) • Reactive Power Generation (Calculation Parameter 𝑐 : 𝐺𝑒𝑛𝑄)

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Figure 33.2.16: Definition of Flexible Data for Grids (ElmNet)

In addition to these results, the complete set of variables from conventional load flow calculations is available. For further information on defining Flexible Data in PowerFactory , please refer to Chapter 10: Data Manager, Section 10.6. A text report is also available and can be generated by clicking on the Output Calculation Analysis icon on the main toolbar. This offers various templates for detailed result documentation.

33.2.2

Initialization

The non-linear optimization requires initialization to generate an initial starting condition. The Iteration page of the OPF dialogue as shown in Figure 33.2.17 allows the user to select the initialization method.

Figure 33.2.17: Initialization Settings for OPF (AC Optimization Method)

Initialization of Non-Linear Optimization Load Flow Displays the load flow command which is used for initialization in the case that no flat start initialization is used. Initialize by Flat-Start The user may choose whether the initialization is performed by a load flow calculation or by a flat start. If it is known in advance that the final solution of the optimization is close to a valid load flow solution, initialization using a load flow calculation results in faster convergence. No Flat Initialization (Use Load Flow Result) If this option is selected, the OPF checks whether an SOPF-initializing ¸ Tˇ load flow result has been calculated prior to the OPF. Here, SOPF-initializing ¸ Tˇ means that the flag Use this load flow for initialization of OPF was enabled in the load flow command dialogue before execution. This flag can be found on the second page of the Advanced Options page in the load flow command dialogue. The result of this load flow is then used as a starting point for the iterative OPF interior-point algorithm. If no valid OPF-initializing load flow result is found, the OPF will recalculate a new load flow. DIgSILENT PowerFactory 15, User Manual

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33.2.3

Advanced Options

Penalty Weighting Factor The penalty weighting factor determines the amount by which the penalty is applied. For example, the smaller the specified penalty weighting factor, the less the penalty will be applied for solutions which are close to constraint limits. Initial Value Initial value of the penalty weighting factor. Target Value Target value of the penalty weighting factor. Reduction Factor A factor by which the current penalty weighting factor will be divided by between the iterations.

Figure 33.2.18: Penalty Weighting Factor Settings for OPF (AC Optimization Method)

33.2.4

Iteration Control

PowerFactory offers the user flexibility in configuring of the number of iterations and the convergence criteria for OPF. The available options on the Iteration Control page of the OPF dialogue are shown in Figure 33.2.19.

Figure 33.2.19: Iteration Control Settings for OPF (AC Optimization Method)

The implementation of the Lagrange-Newton method means that the OPF will internally minimize the 770

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33.2. AC OPTIMIZATION (INTERIOR POINT METHOD) resulting Lagrange function:

𝐿(⃗𝑥, ⃗𝑠, ⃗𝜆) = 𝑓 (⃗𝑥) − 𝜇 ·

∑︁

𝑙𝑜𝑔(𝑠𝑖 ) + ⃗𝜆𝑇 · [𝑔(⃗𝑥) + ℎ(⃗𝑥) + 𝑠]

(33.1)

𝑖

with the Lagrange multipliers (⃗𝜆). The following parameters can be used to alter the stopping criteria for this iterative process. The algorithm stops successfully if the following three criteria are fulfilled: 1. The maximum number of iterations has not yet been reached. 2. All load flow constraint equations g(x)=0 are fulfilled to a predefined degree of exactness (i.e. within an allowable tolerance), which means: • all nodal equations are fulfilled • all model equations are fulfilled 3. The Lagrange function L converges. This can be achieved if: • either the objective function itself converges to a stationary point, or the gradient of the objective function converges to zero. The following parameters are used to configure these stopping criteria. The alteration of the default values for these parameters is recommended only for advanced users. Maximum Number of Iterations Interior-Point Algorithm (Inner Loop) Maximum number of iterations for the interior-point algorithm. Control Loop (Outer Loop) Maximum number of iterations of the outer loop. Convergence Criteria Max. Acceptable Error for Nodes The maximum allowable error for the nodal equations (in kVA). Max. Acceptable Error for Model Equations The maximum allowable error for the model equations (in %). Max. Change of Objective Function Used when Convergence of Objective Function option values of objective function become constant is selected. The user enters a value (in %), below which the Lagrangian is considered to have converged. Max. Value for Gradient of Objective Function Used when Convergence of Objective Function option gradient of objective function converges to zero is selected. The user enters an absolute value, below which the Lagrangian is considered to have converged. Convergence of Objective Function Options relating to the convergence criteria for the Lagrangian function: either the value of the function itself is required to converge to a stationary point, or the gradient of the Lagrangian is required to converge, as described below. Values of objective function become constant If this option is selected, the user is asked to enter a value for the Max. Change of Objective Function. If the change in value between two consecutive iterations falls below this value, the Lagrangian is considered to have converged. Gradient of objective function converges to zero If this option is selected, the user is asked to enter a value for the Max. Value for Gradient of Objective Function. If the gradient falls below this value, the Lagrangian is considered to have converged. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 33. OPTIMAL POWER FLOW For reasons of mathematical exactness, it is strongly recommended to select the latter option, gradient of objective function converges to zero. If the underlying Jacobian matrix is numerically instable, this often results in oscillatory behaviour in the last iterations. Therefore, the latter method provides assurance that the result is in fact a minimum.

33.2.5

Output

Prior to the non-linear optimization, the OPF informs the user (in the output window) of the total number of constraints and controls that will be considered in the subsequent calculation. This information is detailed such that the imposed constraints and the participating controls are counted for each constraint and control categories separately. Two options are available to select the level of detail contained in output messages. These options are available in the Output page of the OPF dialogue and are shown in Figure 33.2.20 and are described below.

Figure 33.2.20: Output Settings for OPF (AC Optimization Method)

Show Convergence Progress Report If this flag is checked on the Output page of the OPF dialogue, the user will get a detailed report on the convergence of the non-linear optimization. For each step of the iteration, the following figures are displayed in the output window (actual variable names are shown parenthesized in italics): • The current error of the constraint nodal equations (in VA) (Err.Nodes); • The current error of the constraint model equations (Err.ModelEqu); • The current error of the inequality constraints (eInequ); • The current value of the gradient of the Lagrangian function (gradLagFunc); • The current value of the Lagrangian function (LagFunc); • The current value of the objective function f to be minimized (ObjFunc); • The current value of the penalty function fpen (PenFunc); • The current values of the relaxation factors (Rlx1, Rlx2) for the primal and dual variables; • The current value of the penalty factor 𝜇 (PenFac)). Show Max. Nodal and Model Equation Error Elements If this flag is checked, the algorithm outputs per iteration, the components which have the largest error in the equality constraints (i.e. mismatch in the load flow equations). An outer loop is wrapped around the central non-linear optimization algorithm. This outer loop is required to perform rounding and optimization of the evaluated tap and shunt positions to discrete values (if desired by the user). The maximum number of outer loops is defined on the Iteration Control page of the dialogue. However, if no convergence is reached with the defined number of outer loops, the user will be informed via a message in the output window that further outer loop iterations are required. 772

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33.3. DC OPTIMIZATION (LINEAR PROGRAMMING)

33.3

DC Optimization (Linear Programming)

The following describes the configuration of the DC optimization formulation of OPF in PowerFactory. Internally, from the settings provided, a linear programming (LP) formulation of the problem is derived. The load flow is calculated using the linear DC load flow method. For general information regarding DC load flow, refer to Chapter 21(Load Flow Analysis). PowerFactory uses a standard LP-solver (based on the simplex method and a branch-and-bound algorithm) which ascertains whether the solution is feasible. The result of the linear optimization tool includes calculated results for control variables, such that all imposed constraints are fulfilled and the objective function is optimized. Provided that a feasible solution exists, the optimal solution will be available as a calculation result. That is, the algorithm will provide a DC load flow solution where all generator injections and tap positions are set to optimal values. The DC load flow solution includes the following calculated parameters (parameter names are given in italics): • For terminals: – Voltage Angle (phiu [deg]) – Voltage Magnitude (u [p.u.]; assumed to be 1.0 p.u. in DC calculation) – Voltage Magnitude (upc [%]; assumed to be 100 % in DC calculation) – Line-Ground Voltage Magnitude (U [kV]) – Line-Line Voltage Magnitude (U1 [kV]) • For branches: – Active Power Flow (P [MW]) – Active Power Losses (Ploss [MW]; assumed to be 0 MW in DC calculation) – Reactive Power Flow (Q [Mvar]; assumed to be 0 MVAr in DC calculation) – Reactive Power Losses (Qloss [Mvar]; assumed to be 0 MVAr in DC calculation) – Loading (loading [%]; Loading with respect to continuous rating) The following parameters are calculated in addition to the results found by the DC load flow: • For generators: – c:avgCosts The fixed cost factor [$/MWh] used in the objective function (i.e. average cost considering the costs at the generatorŠs active power limits). – c:Pdisp Optimal power dispatch for generator. – c:cst_disp Production costs in optimal solution: cst_disp = costs * Pdisp • For Transformers: – c:nntap Optimal tap position. • For loads: – c:Pdisp Optimal load shedding for load.

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33.3.1

Basic Options

The Basic Options page of the OPF dialogue (DC optimization method) is shown in Figure 33.3.1.

Figure 33.3.1: Basic Options page of OPF Dialogue (DC Optimization Method)

33.3.1.1

Method

To perform a DC optimization OPF study, the Method must be set to DC Optimization ( Linear Programming LP) as shown in Figure 33.3.1.

33.3.1.2

Objective Function

The user can select a linear optimization objective function using the list box as shown in Figure 33.3.2. These objective functions are now described.

Figure 33.3.2: Objective Function Selection for OPF (DC Optimization Method)

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33.3. DC OPTIMIZATION (LINEAR PROGRAMMING) Feasibility Check Performs a feasibility check of the network considering the specified controls and constraints (i.e. performs a constrained load flow). Minimization of Costs The objective is to minimize generation costs. To perform a cost minimization calculation for each generator, a cost factor needs to be entered: Cost curve $/MWh per generator element (ElmSym, see Figure 33.2.2) The (linear) algorithm uses a fixed cost-factor [$/MWh] per generator. This cost factor is the average cost considering the costs at the generatorŠs active power limits. The selection of this objective function provides the option of calculating the Locational Marginal Prices (LMPs). For further information on this option refer to: Shadow Prices and Locational Marginal Prices (LMPs). Min. Generator Dispatch Change Minimizes the change in generator dispatch from the generatorsŠ initial value.

33.3.1.3

Controls

The Controls section of the OPF Basic Options page is highlighted in Figure 33.3.3. The basic role of each control is as described for the AC optimization method in Section 33.2.1 (Basic Options)

Figure 33.3.3: Controls Selection for OPF (DC Optimization Method)

The user can select from the following control variables (the names of the associated PowerFactory elements are provided in parentheses): • Generator Active Power Dispatch (ElmSym) In generator optimization, for each selected generator a single control variable is introduced to the system. The total number of generator controls in this case equals the number of selected generators. • Transformer Tap Positions (ElmTr2, ElmTr3) In tap optimization, for each selected transformer DIgSILENT PowerFactory 15, User Manual

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CHAPTER 33. OPTIMAL POWER FLOW a single control variable is introduced to the system. The total number of tap controls in this case equals the number of selected transformers. • Allow Load Shedding (ElmLod) A separate control variable is introduced to the system for each selected load. The total number of load controls in this case equals the number of selected loads. This control variable can be selected in conjunction with any objective function. Note: At least one type of control variable in the Controls section of the OPF dialogue must be selected.

33.3.1.4

Constraints

The three constraints shown in Figure 33.3.4 are as described for the AC optimization method in Section 33.2.1 (Basic Options).

Figure 33.3.4: Constraints Selection for OPF (DC Optimization Method)

For DC optimization the following constraint is also imposed: Transformer Tap Constraints (implicitly imposed) Minimum and maximum tap positions (ElmTr2, ElmTr3) for transformers are considered. These constraints are implicitly imposed when transformer tap positions are specified as controls in the Controls section of the dialogue (see Figure 33.3.4). This means that two constraints are introduced to the LP for the base case tap position calculation. Handling Active power dispatch constraints can be chosen on an individual basis (via a checkbox) per generator. See Figure 33.2.17for setting minimum and maximum constraints for generators for optimization. It should be noted that generator constraints are not implicitly imposed when active power dispatch is selected as a control. Tap position constraints will be implicitly imposed whenever the corresponding tap is a designated control variable, as in Figure 33.2.7. Loading constraints can be chosen on an individual basis (via a checkbox) per line element (ElmLne), as shown in Figure 33.2.11. If loading constraints are included, the maximum loading limits will be 776

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33.3. DC OPTIMIZATION (LINEAR PROGRAMMING) calculated with respect to the type of the element, or with respect to a thermal rating object (IntThrating, as shown in Figure 33.3.5). If a thermal rating object is selected, the limits will be calculated with respect to the Continuous Rating value.

Figure 33.3.5: Thermal Rating Object (IntThrating) Ratings page for Setting Rating Values

Boundary flow constraints can be chosen on an individual basis per boundary element (ElmBoundary ), as shown in Figure 33.2.14.

33.3.1.5

Shadow Prices and Locational Marginal Prices (LMPs)

If the option Calculate Locational Marginal Prices (LMPs) (displayed at bottom of the dialogue in Figure 33.3.4) is selected, the Locational Marginal Price (LMP) is calculated. The Shadow Price is always calculated. The LMP represents the change in the systemŠs total production costs based on a unit change of load at the bus. The calculation of LMP takes into account the network constraints. The system lambda represents the change in the systemŠs total production costs based on a unit change of any load in the absence of network constraints. With the Calculate Locational Marginal Prices (LMPs) option ticked, the execution of the OPF will (on the fly) calculate the LMP for each busbar. The following quantities (current, voltage and powers) are available for all busbars (i.e. ElmTerm elements with Usage set to Busbar ): • LMP in $/MWh (Locational marginal price) • SysLambda in $/MWh (System lambda)

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CHAPTER 33. OPTIMAL POWER FLOW In addition to the LMPs, the DC Optimization always computes the shadow prices. These quantities are available per component, which introduces a constraint to the system. The shadow price then represents the change in the objective function if the constraint is released by a unit change. The shadow prices are available as results for the PowerFactory elements listed below (result variable names are given followed by their corresponding unit). These result variable names are available as Calculation Parameters when defining variable sets for each element. For more information on defining variable sets, refer to Chapter 11: Study Cases, Section 17.4 (Variable Sets). • Line (ElmLne): – ShadowPrice in $/MWh (Shadow price) • 2-Winding Transformer (ElmTr2): – ShadowPrice in $/MWh Shadow price (loading constraint)) – ShadTapMax in $/MWh Shadow price (Maximum Tap constraint)) – ShadTapMin in $/MWh Shadow price (Minimum Tap constraint)) • 3-Winding Transformer (ElmTr3): – ShadowPrice in $/MWh (Shadow price (loading constraint)) – ShadTapMaxLV in $/MWh (Shadow price (Maximum Tap constraint (LV))) – ShadTapMinLV in $/MWh (Shadow price (Minimum Tap constraint (LV))) – ShadTapMaxMV in $/MWh (Shadow price (Maximum Tap constraint (MV))) – ShadTapMinMV in $/MWh (Shadow price (Minimum Tap constraint (MV))) – ShadTapMaxHV in $/MWh (Shadow price (Maximum Tap constraint (HV))) – ShadTapMinHV in $/MWh (Shadow price (Minimum Tap constraint (HV))) • Boundary (ElmBoundary ): – ShadowMaxP in $/MWh (Shadow price (max. total active power constraint)) – ShadowMinP in $/MWh (Shadow price (min. total active power constraint)) • Synchronous Machine (ElmSym): – ShadowMaxP in $/MWh (Shadow price (upper limit active power)) – ShadowMinP in $/MWh (Shadow price (lower limit active power)) • External Grid (ElmXnet): – ShadowMaxP in $/MWh (Shadow price (upper limit active power)) – ShadowMinP in $/MWh (Shadow price (lower limit active power)) • General Load (ElmLod): – ShadowMaxP in $/MWh (Shadow price (max. load shedding)) – ShadowMinP in $/MWh (Shadow price (min. load shedding))

33.3.2

Initialization

The OPF calculation is initialized by a load flow, which is displayed by the Load Flow parameter on the Initialization page of the OPF dialogue. The user can inspect the load flow settings by clicking on the button, as illustrated in Figure 33.3.6. The load flow command contained in the current study case is set here automatically. Within the load flow command, the Calculation Method will be automatically set to DC Load Flow (linear) for use by OPF (when Method is set to one of the LP variants).

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33.3. DC OPTIMIZATION (LINEAR PROGRAMMING)

Figure 33.3.6: Initialization Settings for OPF (DC Optimization Method)

33.3.3

Advanced Options

The Advanced Options page of the OPF dialogue is shown in Figure 33.3.7.

Figure 33.3.7: Advanced Options for OPF (DC Optimization Method)

Load Shedding Options If Allow Load Shedding is among the selected Controls (see Section 33.3.1: Basic Options) on the Basic Options tab, an additional term will be added to the objective function. The weight of this term can be controlled using the Penalty Factor in the Load Shedding Options section of the OPF dialogue. The following term will be added to the objective function, where 𝜔 is the specified Penalty Factor, and 𝑐 is the cost factor of load 𝑖:

𝜔

𝑛𝐶𝑜 𝑛∑︁ 𝐿𝑜𝑎𝑑 ∑︁

𝑐𝑖 |𝐿𝑜𝑎𝑑𝑗𝑖 − 𝐿𝑜𝑎𝑑𝑐𝑢𝑟𝑟 | 𝑖

(33.2)

𝑗=1 𝑖=1

Transformer Tap Deviation Control If tap positions are to be optimized, different solutions can yield the same optimal value for the objective function. One can therefore impose a term to the objective function, which forces the solution to be as close as possible to the initial transformer tap positions. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 33. OPTIMAL POWER FLOW Use Penalty Factor for Tap Deviation If enabled, the following additional term is added to the objective function:

𝜔

𝑛𝑇 𝑟 ∑︁ |𝑡𝑎𝑝0𝑖 − 𝑡𝑎𝑝𝑐𝑢𝑟𝑟 | 𝑖

(33.3)

𝑖=1

Penalty Factor Specifies the weighting factor for the additional objective function term above. Calculation of Transformer Tap Positions Discrete controls (Using direct method) This method calculates discrete tap position values ˇ This method may provide better accuracy, however within the LP (known as the Sdirect ¸ methodT). will yield fewer solutions. Continuous controls (Using outer loop rounding) This method calculates continuous tap position values and then rounds these values to discrete values in the outer loop of the calculation. This method may be faster but the values may not be optimal. Additional Settings Check for Constraint Violations after Optimization This method calculates discrete tap poˇ This method may provide better sition values within the LP (known as the Sdirect ¸ methodT). accuracy, however will yield fewer solutions. Use Presolve procedure If selected, the LP is checked for linear dependencies of constraints. They will be eliminated and only the corresponding (smaller) system is solved.

33.3.4

Iteration Control

Two outer loop settings are available: (i) control of the number of iterations of the algorithm; and (ii) definition of a constraint tolerance. These settings are shown in Figure 33.3.8 and are described below.

Figure 33.3.8: Iteration Control Settings for OPF (DC Optimization Method)

Outer Loop Following the solution of the LP problem, it may be the case that loading constraints are not within their boundaries. The reason is that for taps, the algorithm uses tap sensitivities which assume a linear 780

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33.4. CONTINGENCY CONSTRAINED DC OPTIMIZATION (LP METHOD) change in MW flow per tap step. Since these tap sensitivities depend on the initial tap position, the result becomes inaccurate if the optimal tap position is far from the initial tap position. This inaccuracy can be remedied by an additional outer loop. At each iteration, this outer loop starts with the optimized tap positions which were calculated in the previous loop. The following Outer Loop settings can be entered on this tab: Max. Number of Iterations Maximum number of outer loop iterations until all constraints are fulfilled (within a defined tolerance). Max. Acceptable Error for Constraints Maximum relative error (in %) by which a constraint can be violated while still being considered a feasible solution.). ´ It should be noted that when Max. Number of Iterations is set to S1Š, the LP is solved without outer loops. Limitation of Branch Flow Constraints This option is useful for avoiding long calculation times for large systems. If selected, the LP is solved via an iterative procedure which iterates until no further constraint violations are found (with respect to the Max. Acceptable Error for Constraints parameter). It should be noted that the option Check for Constraint Violations after Optimization on the Advanced Options page must be selected in order to utilise this iterative procedure. An initial set of branch flow constraints must be selected by the user, as described below. Initial Set of Branch Flow Constraints The set of branch flow constraints to be considered can either be the set of N most highly loaded components or a user-defined set. In the case of the set of N most highly loaded components, the program finds these automatically either by using a contingency analysis calculation (in the case of a contingency constrained DC OPF) or by using the initial loadflow (for the other OPF methods). In the case of a user-defined set, the user must define and assign a set of components. A set of components can be defined either via the single line graphic or data manager, by multi-selecting the desired components, right-clicking and selecting Define... → General Set.... This set can then be selected and assigned via the button. Max. number of additional constraints per iteration After solving the LP with an initial set of constraints, the solution is checked against all loading constraints and overloaded components are added to the LP. The parameter Max. number of additional constraints per iteration specifies the maximal number of added components.

33.4

Contingency Constrained DC Optimization (LP Method)

The Contingency Constrained DC Optimization performs an OPF using DC optimization (as described in Section 33.3: DC Optimization (Linear Programming)), subject to various user defined constraints and subject also to the constraints imposed by a set of selected contingencies. The Contingency Constrained DC Optimization also considers user-defined post-fault actions. That is, the optimization can be carried out using contingency cases that include any specified post-fault action. These actions include switch events, generator redispatch events, load shedding events and tap change events. In order for the OPF to consider post-fault actions, the contingency analysis command that is assigned to the OPF must be set to “Multiple Time Phases". The contingency cases can then be defined to contain post-fault actions. For further information on defining contingency cases with post-fault actions, see Chapter 29: Contingency Analysis; Section: 29.5 (The Multiple Time Phases Contingency Analysis Command). In addition to the result variables available for DC optimization, the contingency constrained OPF offers DIgSILENT PowerFactory 15, User Manual

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CHAPTER 33. OPTIMAL POWER FLOW the following result variables (as well as those provided by the DC load flow, as described in Section 33.3: DC Optimization (Linear Programming)): • For generators: – c:Pdisp Optimal generation for each contingency case. The optimum generation for each contingency case is stored as a parameter event object in the corresponding contingency object (ComOutage). Thus, each contingency object will hold parameter events for each selected generator (the name of the parameter event is the name of the generator). The parameter event reflects the optimal generation for that generator in the given contingency case. • For Transformers: – c:nntap Optimal tap positions for each contingency case. The optimum tap positions for each contingency case are stored as a parameter event object in the corresponding contingency case object (ComOutage). Thus, each contingency object (ComOutage) will hold parameter events for each selected transformer (the name of the parameter event is the name of the transformer). The parameter event reflects the optimal tap position for that transformer in the given contingency case – c:mxTpChng (_l,_m, _h) mxTapChng is the maximum tap change deviation between the optimal base case tap position and the optimal tap position considering all contingencies. For 3-winding transformers, HV-, MV- and LV-side tap changes are calculated individually. • For loads: – c:Pdisp Optimal load shedding for each contingency case. The optimum load shedding for each contingency case is stored as a parameter event object in the corresponding contingency case object (ComOutage). Thus, each contingency object will hold parameter events for each selected load (the name of the parameter event is the name of the load). The parameter event reflects the optimal load shedding for that load in the given contingency case.

33.4.1

Basic Options

The Basic Options page of the OPF dialogue (contingency constrained DC optimization method) is shown in Figure 33.4.1.

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33.4. CONTINGENCY CONSTRAINED DC OPTIMIZATION (LP METHOD)

Figure 33.4.1: Basic Options page of OPF Dialogue (Contingency Constrained DC Optimization Method)

Method To perform a contingency constrained OPF study, the Method must be set to Contingency Constrained DC Optimization (LP) as shown in Figure 33.4.1. Contingency Analysis This is a reference to the Contingency Analysis (ComSimoutage) command to be used during the contingency constrained OPF. The user can select and set this contingency analysis command via the button, and view or edit the contingency analysis command settings using the arrow button . If the user would like the contingency cases to use post-fault actions, the Method used by the contingency analysis command must be set to Multiple Time Phases. See Chapter 29: Contingency Analysis; Section: 29.5 (The Multiple Time Phases Contingency Analysis Command). Objective Function The selection of objective function for Contingency Constrained DC Optimization includes the same objective functions as those provided for DC Optimization (see Section 33.3.1: Basic Options). Two additional objective functions are provided, which are shown in Figure 33.4.2 and described below.

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Figure 33.4.2: Objective Function Selection for OPF (Contingency Constrained DC Optimization Method)

Min. Generator Dispatch Change (Pre-to-Postfault) Minimizes the sum of the generator dispatch changes between the base case and each contingency case. Min. Transformer Tap Change (Pre-to-Postfault) Minimizes the sum of the tap position changes between the base case and each contingency case. Controls The definition of control variables for the contingency constrained DC optimization method differs slightly from the DC optimization method, however the basic fundamental role of each control is as described for the AC optimization method in Section 33.2.1 (Basic Options). The Controls section of the OPF dialogue is highlighted in Figure 33.4.3.

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33.4. CONTINGENCY CONSTRAINED DC OPTIMIZATION (LP METHOD)

Figure 33.4.3: Controls Selection for OPF (Contingency Constrained DC Optimization Method)

The user can select from the following control variables: • Generator Active Power Dispatch (ElmSym, ElmXnet) Dispatch in Contingencies – Use base case dispatch: For all contingency cases, use the generator dispatch from the base case. Using this setting, a single control variable is introduced to the system for each selected generator. The total number of generator controls in this case equals the number of selected generators and/or external networks. – Allow different dispatch: For each contingency case, allow a generator dispatch different to that used in the base case. Using this setting, for each selected generator, a control variable is introduced for the base case and for each contingency case. This option must be selected from the drop-down box when the objective function Min. Generator Dispatch Change (Preto-Postfault) has been selected. The total number of generator controls in this case equals: (number of selected generators) * (1 + number of selected contingencies) • Transformer Tap Positions (ElmTr2, ElmTr3) Tap Positions in Contingencies – Use base case tap positions: For all contingency cases, use the transformer tap positions from the base case. Using this setting, a single control variable is introduced to the system for each selected transformer. The total number of tap controls in this case equals the number of selected transformers. – Allow different tap positions: For each contingency case, allow tap positions different to those used in the base case. Using this setting, for each selected transformer, a control variable is introduced for the base case and for each contingency case. This option must be selected from the drop-down box when the objective function Min. Transformer Tap Change DIgSILENT PowerFactory 15, User Manual

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CHAPTER 33. OPTIMAL POWER FLOW (Pre-to-Postfault) has been selected. The total number of tap controls in this case equals: (number of selected transformers) * (1 + number of selected contingencies) • Allow Load Shedding (ElmLod) A separate control variable is introduced to the system for the base case and for each contingency case. This control variable can be selected in conjunction with any objective function. The total number of load controls equals: (number of selected loads)*(1 + number of selected contingencies) Constraints The Constraints section of the OPF dialogue for the contingency constrained DC optimization method is shown in Figure 33.4.4. This formulation of OPF performs a contingency analysis for a predefined set of contingencies (ComOutage objects; i.e. a set of interrupted components per contingency case). The Max. Loading (parameter name: maxload) for lines and transformers (ElmLne, ElmTr2, ElmTr3; (one constraint per bus)) for each contingency case is considered in the calculation. For each loading constraint, the number of constraints added to the LP will be: 2*(number of contingencies). In addition to the constraints provided for DC optimization (for further information see Section 33.3.1: Basic Options), the contingency constrained DC optimization method offers additional constraints: Maximum Number of Tap Changes per Contingency If this checkbox is ticked, then for each contingency, no more than the maximum tap position change steps from the base case to the contingency case are allowed over all transformers (i.e. for a given contingency, a constraint is enforced on the sum of all maximum difference of base case to contingency case taps, over all transformers). Transformer Tap Constraints (implicitly imposed) Minimum and maximum tap positions for transformers(ElmTr2, ElmTr3) are considered. These constraints are implicitly imposed when transformer tap positions are specified as controls in the Controls section of the OPF command dialogue (see Figure 33.4.4). This leads to two constraints in LP formulation for the base case tap position calculation, and to: 2 x (1 + number of contingencies) constraints for contingency case calculations.

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33.4. CONTINGENCY CONSTRAINED DC OPTIMIZATION (LP METHOD)

Figure 33.4.4: Constraints Selection for OPF (Contingency Constrained DC Optimization Method)

Handling Active power dispatch constraints can be chosen on an individual basis (via a checkbox) per generator. See Figure 33.2.12 for setting minimum and maximum constraints for generators for optimization. Tap position constraints will be implicitly imposed whenever the corresponding tap is a designated control variable, as illustrated in Figure 33.2.7. The tap position limits are defined in the transformerŠs assigned Type. Loading constraints can be chosen on an individual basis (via a checkbox) per line element (ElmLne) and per transformer element (ElmTr2, ElmTr3), as shown in Figure 33.2.11. Once a loading constraint for a specific line or transformer is imposed, it will be considered by all contingencies contained in the contingency list. If loading constraints are included, the maximum loading limits will be calculated with respect to the type of the element, or with respect to a thermal rating object (IntThrating, as shown in Figure 33.3.5). If a thermal rating object is selected, the limits will be calculated with respect to the Continuous Rating value. Boundary flow constraints can be chosen on an individual basis per boundary (ElmBoundary ), as shown in Figure 33.2.14. Once a boundary constraint for either the maximum total active power limit or minimum total active power limit is imposed, it will be considered by all contingencies in the contingency list. The list of contingencies to be considered by the OPF is selected by choosing a specific contingency analysis command (parameter Contingency Analysis in the OPF dialogue, Basic Options tab), which contains in its folder the contingency objects (ComOutage) to be considered.

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33.4.2

Initialization

As described for DC optimization. Please refer to Section 33.3.2 (Initialization).

33.4.3

Advanced Options

As described for DC optimization. Please refer to Section 33.3.3 (Advanced Options).

33.4.4

Iteration Control

As described for DC optimization. Please refer to Section 33.3.4 (Iteration Control).

33.4.5

Output

For contingency constrained DC OPF, results can be optionally recorded for those branches which exceed a selected limit value. This can be done for both the non-optimized results and the optimized results. For each recording of results (i.e. with optimized or non-optimized values) a separate result file must be chosen.

Figure 33.4.5: Output Settings for OPF (Contingency Constrained DC Optimization Method)

Contingency Analysis Results Allows the selection of result files for the contingency analysis results with and/or without optimized controls. Results (before optimization) The result file in which to store the non-optimized results. Results (after optimization) The result file in which to store the calculated (optimized) results. Limits for Recording The limits displayed here are set in the selected Contingency Analysis command on the Basic Options page of the contingency analysis command dialogue. They define the limits outside of which results will be written to the result file(s). See Chapter 29: Contingency Analysis, Section 29.4.1 for further information. 788

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33.4. CONTINGENCY CONSTRAINED DC OPTIMIZATION (LP METHOD) Reports on Following a contingency constrained DC OPF calculation, the Output of Results command button the main toolbar becomes active. This command allows the printing of various reports, as illustrated in Figure 33.4.6. The following reports are offered: Optimal Solution Prints a detailed report to the output window, showing all optimal settings for generators, transformers and loads, component-wise, for all contingencies. An additional flag (Report only Contingency with max. Deviations) can be checked to show only the settings for the contingency where the maximum deviation occurs. Optimal Solution (per Contingency) Prints a detailed report to the output window, showing all optimal settings, on a per-contingency basis. Maximum Loadings Prints a detailed report to the output window showing the maximum loadings of components against the relevant contingency. The user may define the loading limit for which to report violations, and may select whether to report only the highest loadings for branch components. Moreover, this report facilitates the display of results before and after the optimization. Loading Violations Prints a report to the output window showing components with loading violations, against the relevant contingency. The user may define the loading limit for which to report violations, and may select whether to report only the highest loadings for branch components. Additionally, the reporting of violations in contingency cases may be suppressed if violations already exist in the base case. Violations per Case Prints a report to the output window showing components with loading violations, on a per-contingency case basis. The user may define the loading limit for which to report violations, and may select whether to report only the highest loadings for branch components. Additionally, the reporting of violations in contingency cases may be suppressed if violations already exist in the base case.

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Figure 33.4.6: Output of Results Command for Contingency Constrained DC OPF)

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Chapter 34

Techno-Economical Calculation 34.1

Introduction

This chapter presents the tools available to perform Techno-Economical Calculations in PowerFactory . It provides a general description, technical background, description of the command dialogues, and an example calculation. The Techno-Economical Calculation (ComTececo) can be accessed from the toolbar as shown in Figure 34.1.1 Techno-economical calculations are used to perform an economic assessment and comparison of network expansions (projects) through an analysis of: • The cost of electrical losses. • The economic impact of failure rates (reliability). • Investment costs, including initial costs, initial value, scrap value, and expected life span. • Project timing.

Figure 34.1.1: How to access the Techno-Economical Calculation

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34.2

Requirements for Calculation

Prior to conducting a Techno-Economical Calculation, economic data should be defined within each Expansion Stage (IntSstage). To define economic data, right-click on the Expansion Stage, click Edit, and select the Economical Data tab. Parameters to be defined are as follows: Costs for expansion Define the Investment costs in “k$", and Additional costs in “k$/a". Commercial equipment value Define the Original value in “k$", Scrap value in “k$", and Expected life span in years “a". Note that the Expected life span is used in the economic calculation, it does not take the Variation out of service at the end of the expected life span.

34.3

Calculation Options

34.3.1

Basic Options Page

Calculation Points Select to either Calculate: • once per year. Calculations are executed once per year from the 1st day of the Calculation Period Start (01.01.XXXX, 00:00:00) to the last day of the year at the calculation period End (31.12.YYYY, 23:59:59). • for every expansion stage. Calculations are executed on the 1st day of the Calculation Period Start, at the Activation Time of each Expansion Stage. • for user-defined dates. Calculations are executed on the 1st day of the Calculation Period Start, at each user-defined date. To define dates, Insert rows to the Calculation Points table and specify the required dates. To automatically populate the table of calculation points with once per year dates and for every expansion stage dates, select Get keyAll keyCalculation keyPoints. The dates can then be edited as required (note that it is not possible to append rows beyond the end date). Note: Irrespective of the calculation option selected, the results are reported annually. This provides user-flexibility to optimize the performance of the Techno-Economical Calculation, whilst retaining the ability to compare annual results with different calculation options.

Strategy Click Show Activated Variations to show Activated Variations. Only Expansion Stages within Activated Variations, and an Activation Time within the Calculation Period will be considered by the calculation. Calculatory Interest Rate Specify the Calculatory Interest Rate to be used in the Net Present Value (NPV) calculations. Tolerance Specify a “Tolerance for calculation points (in days)" for activation of Expansion Stages. If, for example, a calculation is to be performed once per year, and all Expansion Stages with Activation Times within January of that year are to be considered as in-service for the entire year, a tolerance of “31 days" could be specified. Load growth Optionally Incorporate load growth in the calculation, to consider load growth within each calculation 792

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34.3. CALCULATION OPTIONS interval. In contrast to the case where no load growth is incorporated and costs for a calculation period are calculated at the beginning of that period, enabling this flag will lead to a second cost calculation at the end of the current calculation period. Corresponding costs are then calculated based on both values. Load growth is defined via parameter characteristics (see Chapter 16: Parameter Characteristics, Load States, and Tariffs for details of how to define parameter characteristics).

34.3.2

Costs Page

Optionally consider Losses, Interruption Costs, User-defined Costs, and Annual additional costs, and select whether to Optimize Tie Open Points. Losses • Optionally modify the Load Flow Calculation options via the pointer to the Load Flow Calculation command. • Select whether to consider losses for the whole system, or for a user-defined set of substations/feeders. If more than one feeder or substation is selected, PowerFactory automatically creates a Set within the active Study Case, by default named “Techno-eco. Calc. - Substations/Feeder Set". • Define the Costs for Losses (Load) in “$/kWh", relating to line losses. • Define the Costs for Losses (no Load) in “$/kWh", relating to transformer no-load losses. Interruption Costs Modify the Reliability Assessment options. By default, a new Reliability Assessment command object is created within the Techno-Economical command. See Chapter 30 for details of how to configure the Reliability Command options. For a Techno-Economical calculation, it is generally recommended that the following options are selected in the Reliability Assessment Command: • Basic Options → Load flow analysis • Basic Options → Distribution (Sectionalizing, Switching actions) • Advanced Options → Automatic Power Restoration • Advanced Options → Do not save corresponding events User-defined costs Optionally select a user-defined DPL Cost Assessment Script. This functionality may be required for detailed analysis where factors besides losses and outage costs are to be considered in the calculation. Annual additional costs Optionally define Annual additional costs in "k$/a". These are costs that are to be applied irrespective of the network development strategy. Optimize Tie Open Points Optionally select to calculate losses from the output of the TOPO calculation. The network open point(s) will be re-configured during the Techno-Economical Calculation in order to minimize losses, in accordance with the options selected in the TOPO command. By default, a new TOPO command object is created within the Techno-Economical command. See Section 35.4: Tie Open Point Optimization, for details on how to configure the TOPO command. Note: If the costs of losses are not considered by the Techno-Economical command directly, Optimize Tie Open Points may still be selected so that the impact of network switching configuration is considered by the calculation, where either Interruption Costs or Additional Costs is selected.

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34.3.3

Output Page

Results A reference (pointer) to the result object. Report (Optionally) select the format of results printed to the output window. The report includes a summary of selected calculation options, and annual costs, total costs, and Net Present Value (NPV).

34.4

Example Calculation

Consider the following Techno-Economical Calculation example, which also consolidates functionality presented on the following topics: • Project Variations: Discussed in Chapter 15 (Network Variations and Expansion Stages). • Reliability: Discussed in Chapter 30 (Reliability Assessment). • Parameter Characteristics and Tariffs: Discussed in Chapter 16 (Parameter Characteristics, Load States, and Tariffs). The current year is “2010". There are four 12 MW loads connected to DoubleBusbar/A and DoubleBusbar/B. In the current arrangement the line “Existing Line" from “Sub 1" is lightly loaded (see Figure 34.4.1). High load growth is expected from 2010 to 2016, with constant demand thereafter. To model the changes in demand, a One Dimension - Vector Characteristic from 2010 to 2020 has been defined for each load. By setting the Study Time to 2014, it has been determined that “Existing Line" will be loaded at close to the thermal rating in this year (see Figure 34.4.2). Based on this, it has been determined that a new substation is required in 2015 to off-load the existing line. Figure 34.4.3 shows the case with the Study Time set to 2015, and the new substation “Sub 2" in service. Half of the load from “Sub 1" has been transferred to “Sub 2". Note that the new substation has been implemented as a PowerFactory Variation, and hence is shown with yellow dashed lines in cases where the Study Time is prior to 2015.

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34.4. EXAMPLE CALCULATION

Figure 34.4.1: Example case,study time “2010"

Figure 34.4.2: Example case,study time “2014"

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Figure 34.4.3: Example case,study time “2015"

However, the previous analysis has not considered the economic impact of interruption costs. In the “2010", when there is an outage of the line from “Sub 1" there are no alternative paths to re-establish supply to either load. With the new line and DoubleBusbar/A and B in service, there is an alternative path to re-establish supply to loads in the event of an outage on either “New Line" or “Existing Line". To understand the economic implications of commissioning the project prior to 2015, in particular the sensitivity of the cost of losses and cost of interruptions to the project commissioning date, a TechnoEconomical Analysis is performed for a number of Activation Times. To perform the analysis, the Variation activation time T(act.) is varied from 2010 to 2015, and the Net Present Value (NPV) of the Strategy is calculated over the period 2010 to 2020. In the example, outage data has been entered for the lines “New Line" and “Existing Line", and a Global Energy Tariff has been defined for loads from the Reliability command Costs page. Due to the trade-off between Energy Interruption Costs (increasing in this example due to load growth) and cost-benefits associated with delaying the project (based on the specified interest rate), the optimum year for project commissioning is determined to be 2011, and not 2015. The NPV is around 11 % lower in 2011 than in 2015. Table 34.4.1 below summarizes the results of the Techno-Economical calculations.

Table 34.4.1: Summary of Calculation Results Note: To automatically calculate the optimal Activation Time for an Expansion Stage, in the Data Manager, right-click on the Expansion Stage, select “Execute DPL Scripts" and run the “Efficiency ratio calculation" script. 796

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Chapter 35

Distribution Network Tools 35.1

Introduction

The chapter presents the PowerFactory tools for assessment and optimization of distribution networks. The areas of analysis are highlighted in Figure 35.1.1 Each section of this chapter introduces the tool, presenting a general description, the objective function, the optimization procedure, and the command dialogues.

Figure 35.1.1: How to access the Distribution Network Optimization tools

35.2

Voltage Sag

The Voltage Sag Table Assessment (ComVsag) can be used to assess the expected frequency and severity of voltage sags within a network during an operating period, and determine the expected number of equipment trips due to deep sags. The PowerFactory Voltage Sag tool calculates a short-circuit at the selected load points within the system and uses the failure data of the system components to DIgSILENT PowerFactory 15, User Manual

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CHAPTER 35. DISTRIBUTION NETWORK TOOLS determine the voltage sag probabilities. Voltage sag analysis is similar to probabilistic reliability analysis, in that it uses fault statistics to describe the frequency of faults, and then use these statistics to weight the results of each event and to calculate the overall effects of failures. However, reliability analysis looks for sustained interruptions as one aspect of quality of supply, whereas voltage sag analysis calculates the voltage drop during the fault until the protection system has disconnected the defective component. This section describes the calculation options, how to perform a Voltage Sag Table Assessment, and how to view the results.

35.2.1

Calculation Options

35.2.1.1

Basic Options Page

Figure 35.2.1: Voltage Sag Table Assessment - Basic Options

Load selection Reference to the set of load points. A load point can be defined by a busbar, terminal, or load. Short-circuit command Displays the short-circuit command that is used. The options for the short-circuit type will be changed during the voltage sag calculation, depending on the Advanced Options specified in the ComVsag dialogue. However, other settings can be inspected or changed by clicking on the Edit button ( ). Results Reference to the result file that is used for storage of results. Exposed area limit This defines the minimum remaining voltage for the voltage sag calculation to continue calculating shortcircuits at busbars which are further away from the selected load points. If short-circuits at all busbars (at a certain distance away from all load points) result in voltages at the load points being higher than this limit, then no further short-circuit will be analyzed.

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35.2. VOLTAGE SAG 35.2.1.2

Advanced Options Page

Figure 35.2.2: Voltage Sag Table Assessment - Advanced Options

TheAdvanced Options page shows the various short-circuit types that can be analyzed by the voltage sag assessment command. All components for which a failure model has been defined use the same short-circuit frequency. The relative frequency for each type of short-circuit is entered uniformly for all components.

35.2.2

How to Perform a Voltage Sag Table Assessment

A voltage sag table assessment is performed in two phases: 1. A result file with remaining voltages and short-circuit impedances is created by executing the ComVsag command. This can be done by selecting one or more nodes, right-clicking and executing the Calculate... → Voltage sag table... option, or by initiating the command directly from the main toolbar by clicking on the Voltage Sag Table Assessment icon ( ). 2. A voltage sag plot is created by selecting one or more of the nodes for which the ComVsag command was executed, right-clicking and selecting the option Show → Voltage Sag Plot... Alternatively, • The Load selection in the ComVsag dialogue can be completed manually with a set of objects. A load point is defined by a terminal, a busbar, or by a single-connection element (a load, motor, generator, etc.). These kinds of elements can be multi-selected from the single-line diagram or data manager. Once selected, right-click on them and select Define... → General Set from the context-sensitive menu. This set can then be selected as the Load selection. • A voltage sag plot can be created on a virtual instrument page manually, and the load points can then be selected from the list of analyzed load points. If several objects are selected which are all connected to the same busbar, then that busbar will be added only once to the set of load points. The Load selection parameter in the voltage sag assessment command should be set to use the SetSelect which has the Used for: Voltage sag table flag set. However, any other selection can be assigned to the Load selection. The voltage sag analysis simulates various faults at the selected busbars. The calculation starts with the selected load points, and proceeds to neighbouring busbars until the remaining voltage at all load DIgSILENT PowerFactory 15, User Manual

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CHAPTER 35. DISTRIBUTION NETWORK TOOLS points does not drop below the defined Exposed area limit. The remaining voltages and the short-circuit impedances for all load points are written to the result file specified by the Results parameter. After all relevant busbars have been analyzed, the sag table assessment continues by analyzing shortcircuits at the midpoint of all lines and cables that are connected between the relevant busbars. Again, the remaining voltages and short-circuit impedances for all load points are written to the result file. After the complete exposed area has been analyzed in this way, the result file contains the values for Z_F1, Z_F2, Z_F0, Z_S1, Z_S2, Z_S0 and ura, uia, urb, uib, urc, uic for the two ends of all relevant lines and cables and at their midpoints. To reduce computation time, the written impedances are interpolated between the ends of a line and the middle with a second-order polynomial. Then, the remaining voltages and various source impedances are estimated. These estimated impedances are also interpolated between the ends and the midpoint. The interpolated impedances are then used to estimate the remaining voltages between the ends and the midpoints of the lines or cables. This quadratic interpolation gives a good approximation for longer lines, as well as parallel lines.

35.2.3

Voltage Sag Table Assessment Results

The voltage sag tables are not calculated until a voltage sag plot is constructed. Upon reading the remaining voltages, short-circuit frequencies and short-circuit impedances from the result file, a voltage sag table is constructed for each selected load point. Figure 35.2.3 shows the voltage sag plot dialogue.

Figure 35.2.3: Voltage Sag Plot Dialogue

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35.2. VOLTAGE SAG Because there is no single definition of a voltage sag, the plot offers a selection of sag definitions: • Minimum of Line-Neutral Voltages. • Minimum of Line-Line Voltages. • Minimum of Line-Line and Line-Neutral Voltage. • Positive Sequence Voltage. Secondly, the x-variable against which the sag frequency will be shown has to be selected. Possible x-variables are: • Remaining Voltage. • Nom. Voltage at Shc-Busbar. • Fault Clearing Time. • Short-Circuit Type. Additionally, the x-variable can be sub-divided according to a split-variable (parameter name: Split Bars in). Possible split variables are: • no split. • any of the possible x-variables. The same parameter cannot be selected for the x-variable and the split-variable. An example of the resulting voltage sag plot, in accordance with the settings shown in Figure 35.2.3 is shown in Figure 35.2.4.

Figure 35.2.4: Example Voltage Sag Plot

The voltage sag plot always shows the annual frequency of occurrence on the y-axis. The example plot shows a bar for each load point for each x-variable, which is the Remaining Voltage. All three loads can be seen to suffer either deep sags (remaining voltage less than 0.4 p.u.), or shallow DIgSILENT PowerFactory 15, User Manual

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CHAPTER 35. DISTRIBUTION NETWORK TOOLS sags, although the values at 0.8 p.u. are also significant. Each bar is subdivided to the nominal voltage at SHC-Busbar. The shallow sags are caused by the low voltage network, as well as the deep sags. The high voltage network seems to cause moderate voltage sags. This is caused by the fact that the low voltage networks in this example are radially operated and the higher voltage networks are meshed. More detailed information about a specific value in the voltage sag plot can be viewed in the balloon help that appears when placing the mouse over a bar or part of a bar (without clicking). The voltage sag plot dialogue has a Report button (see Figure 35.2.3) which outputs the voltage sag plot data to the output window. A table for each selected load point will be written in accordance to the selected Voltage Sag definition, x-Variable and Split Bars in selection.

35.3

Voltage Profile Optimization

The Voltage Profile Optimization (VPO) command (ComVoltplan) is used to optimize distribution transformer taps over the expected range of network load and generation conditions. It can be selected from Distribution Network Tools, as shown in Figure 35.1.1. The VPO calculation considers two scenarios: • A maximum demand/minimum generation scenario, or “Consumption Case". • A minimum demand/maximum generation scenario, or “Production Case". It requires that loads be represented as medium voltage (MV) loads (ElmLodmv ). MV load elements include transformer and LV network parameters, as illustrated in Figure 35.3.1. To show Terminal colouring based on maximum / minimum LV grid voltages, from the main menu select View → Diagram Colouring (or select the Diagram Colouring icon). Under 3. Other select Results → Voltages / Loading. Click on Colour Settings, go to second page of the Voltages / Loading page, and select Consider LV grid voltages for colouring. In the example below, the minimum voltage is below the lower limit and the maximum voltage is above the upper limit (the limits set in the colouring options), therefore the terminal shows two colours.

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35.3. VOLTAGE PROFILE OPTIMIZATION

Figure 35.3.1: MV load example Note: The transformer tap changer is represented on the LV side of the MV load.

35.3.1

Optimization Procedure

The optimization procedure is summarized as follows: 1. If Distribution Transformer Tap Limits are specified by the user, limit the tap range of transformers to within the limits Min. allowed tap position and Max. allowed tap position. This is illustrated in Figure 35.3.2, where a transformer with seven tap positions is limited to taps “-1" to “2" to limit the transformer voltage rise to 7 % and voltage drop to -5 %. The height of each bar is determined by the voltage rise and voltage drop across the transformer in the production and consumption cases respectively.

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Figure 35.3.2: Distribution Transformer Tap Limits 2. Calculate the Upper tap limit and Lower tap limit, based on settings that will keep the range of expected LV Grid voltages within the Upper voltage limit and Lower voltage limit, as illustrated in Figure 35.3.3, where the limits are set to between 0.92 pu and 1.10 pu. 3. Both tap positions “0" and “1" would be acceptable, and maintain transformer voltage drop and LV grid voltages within acceptable limits. The optimization routine selects the lower tap limit (position “0" in Figure 35.3.3) in order to minimize the voltage rise.

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35.3. VOLTAGE PROFILE OPTIMIZATION

Figure 35.3.3: Voltage Limits for LV Grids

The possible scenarios for optimization are summarized as follows: 1. There is a single tap position that will satisfy both LV grid lower and upper voltage limit -> this tap is selected. 2. There are tap positions that will satisfy both LV grid lower and upper voltage limits -> the lowest tap position is selected in order to favour limiting voltage rise in the production case. 3. There are tap positions that will satisfy the LV grid upper voltage limit, but all of them violate the lower voltage limit -> the highest tap position that will not violate the upper voltage limit is selected. 4. There are tap positions that will satisfy the LV grid lower voltage limit, some of which will violate the upper voltage limits -> the tap position that will not violate the upper voltage limit is selected, even if lower voltage limits are violated further as a result. 5. There are no tap position/s that will satisfy both LV grid lower and upper voltage limits -> the lowest tap position is selected in order to minimize voltage rise in the production case. Note that Distribution Transformer Tap Limits, if specified in the Advanced Options, take precedence over the Upper and Lower Voltage limits specified in the Basic Options.

35.3.2

Basic Options Page

Load Flow Calculation This is a reference (pointer) to the load-flow command used by the optimization algorithm. Voltage Limits for LV grids Upper and lower voltage limits for LV grids (in per unit).

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CHAPTER 35. DISTRIBUTION NETWORK TOOLS Settings for Consumption Case MV load and generation scaling factors for the consumption case. Generally, the consumption case will have high demand (e.g. 100 %) and low generation (e.g. 0 %). Settings for Production Case MV load and generation scaling factors for the production case. Generally, the production case is the opposite of the consumption case, and will have low demand (e.g. 25 %) and high generation (e.g. 100 %). Show Load flow with optimized Transformer Taps, for After the optimization of transformer taps for the consumption and production cases, a load flow is calculated using the optimized tap settings. This radio button selects whether the load flow results shown are for the consumption or production case.

35.3.3

Output Page

Report A reference (pointer) to the result report output. It is possible to select the reports to be displayed, and whether they are shown in Tabular or ASCII format.

35.3.4

Advanced Options Page

Distribution Transformer Tap Limits Transformer Maximum Allowed Voltage Rise and Maximum Allowed Voltage Drop can optionally be specified. These limits take precedence over the voltage limits specified on the Basic Options page.

35.3.5

Results of Voltage Profile Optimization

The result of a voltage profile optimization is a tabular or ASCII report with the recommended tap settings, including details of MV loads with Critical Voltage Drop or Rise. An example of the Optimal Transformer Tap Positions section of the report is shown below in 35.3.4 (results consistent with Figure 35.3.1, and the discussion in Section 35.3.1).

Figure 35.3.4: Voltage Profile Results

The recommended tap settings are also available from the flexible data page of MV loads under the load-flow calculation parameter “c:nntap". To update the network model with the recommended tap settings, the user may either manually adjust MV load tap positions, or click the Update Database icon on the main toolbar ( ), and update the case with the calculated Distribution Transformer Taps. To display a plot of the resultant profile for one feeder for both the consumption and production case, select the Voltage Profile Plot icon ( ). Figure 35.3.5 shows an example plot, where: • min_v and max_v are the minimum and maximum transformer HV side voltages. • uminLV and umaxLV are the minimum and maximum transformer LV side voltages. 808

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35.4. TIE OPEN POINT OPTIMIZATION • uminLVfeed and umaxLVfeed are the minimum and maximum LV grid voltages.

Figure 35.3.5: Voltage Profile Plot

35.4

Tie Open Point Optimization

The function of the Tie Open Point Optimization (TOPO) (ComTieopt) is to optimize a radial system of connected feeders by determining the best location for network open points. An open point can be moved by the TOPO tool by opening and closing switches on the networks to be optimized. This chapter is separated into three sub-sections. Firstly, the steps to access the TOPO tool are described. Next, the background and function of the TOPO tool is presented and finally the procedure for running a Tie Open Point Optimization is described. The Tie Open Point Optimization Command can accessed as shown in Figure 35.1.1

35.4.1

Tie Open Point Optimization Background

The function of the Tie Open Point Optimization (TOPO) tool is best explained using an example. Consider the network illustrated in Figure 35.4.1

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Figure 35.4.1: Example network for Tie Open Point Optimization

The network consists of three feeders, one from each of the three “stations". Each feeder begins at a “station" and ends at one of the two illustrated open points. The two open points in this network are not necessarily the optimum open points. For example, it might be more economic (i.e. less network losses and / or less impact of outages) to shift these open points by closing the open switches and opening two switches in different positions on the feeders. The purpose of the TOPO tool is determine these optimum open points automatically. Additionally, the TOPO tool can automatically consider network voltage and thermal constraints - for instance it might be economic to shift an open point in terms of reducing systems losses, however doing so might cause a cable to overload.

35.4.2

How to run a Tie Open Point Optimization

This section describes the procedure for running a Tie Open Point Optimization (TOPO) calculation. The steps are summarized below, and discussed in more detail in the following sections: • How to Create Feeders. • How to configure the Tie Open Point Optimization Command. • How to configure constraints for the Tie Open Point Optimization. • How to configure the Advanced Options. • How to configure Reliability Options. How to Create Feeders The TOPO tool requires that feeders are defined for the section of the network that you wish to optimize. Additionally, the TOPO tool only works on radial feeders - mesh systems cannot be optimized 810

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35.4. TIE OPEN POINT OPTIMIZATION automatically. Furthermore, it is recommended that the target feeders for optimization do not have any overloaded components or voltage violations in the base case. To define a feeder, right-click the cubicle at the beginning of the feeder and select the Define → Feeder. Alternatively, for fast creation of multiple feeders right-click the bus the feeder/s are connected to and select the option Define → Feeder. More information on feeders and feeder creation can be found in Chapter 13: Grouping Objects, Section 13.5. How to configure the Tie Open Point Optimization Command After a set of feeders has been defined, open the TOPO tool and configure the basic options: 1. Click the Change Toolbox icon (

) and select Distribution Network Tools.

2. Open the dialogue for the Tie Open Point Optimization tool (

).

3. Use the selection control for Feeding Points to select previously defined feeder/s, or a feeder “Set". If the Select option is chosen and multiple feeders are selected, a “Set" of feeders will automatically be created within the active study case. By default the set will be named ’Tie Open Point Optim. - Feeder Set’. Note: It is generally recommended to define all feeders in the network as Feeders, and to conduct a TOPO calculation for ’All Feeders’. 4. Select the desired Objective Function to minimize losses and / or reliability indices. If Optimization of Reliability Indices or Cost Optimization (Losses + Reliability) is selected, complete the required fields on the Reliability page, see (How to configure Reliability Options). 5. “Balanced, positive sequence" or “Unbalanced" network representation can be selected. The Load-flow command referenced below these radio buttons is automatically adjusted to the correct calculation method based on this selection. 6. Optional: You can inspect and alter the settings of the load-flow command that is used for determining the losses and identifying the constraints of the system by clicking the blue selection arrow next to load-flow command. 7. Optional: Change the “Saving of solution" option. The two options are as follows: • Change Existing Network (Operation Scenario). This is the default option. The TOPO tool modifies the base network model. Note that if a variation is active, the changes will be implemented in the variation. • Record to Operation Scenario. If you choose this option a selection control appears and you can choose an existing operation scenario to save the results of the Optimization procedure to. Alternatively, you can leave the selection empty and PowerFactory automatically activates a new Operation Scenario called “Tie Open Point Optimization Results". Any changes made to the network as a result of the optimization procedure are stored within this operation scenario. You can revert to the original network by disabling the scenario. 8. Optional: Disable the “Report" flag. This control, enabled by default, allows you to turn off the automatic printing of an ASCII report to the output window. 9. Optional: Select the Before Optimization and After Optimization results objects. How to configure constraints for the Tie Open Point Optimization It is optional whether you choose to consider thermal and voltage constraints for the Tie Open Point Optimization. If you wish to consider constraints follow these steps: 1. Open the Tie Open Point Optimization dialogue and select the Constraints page. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 35. DISTRIBUTION NETWORK TOOLS 2. Optional: Choose to enable or disable the option Consider Thermal Constraints. If enabled, the TOPO tool will automatically consider thermal constraints in the network. Therefore, if an optimal point were to cause an thermal overload on any system component, then this would not be considered as a valid open point for reconfiguration of the system. There are two more options for thermal constraints: • Global constraint for all components. This is the default option. If enabled you must enter a maximum thermal loading percentage in the Max. thermal loading of components field. Note this option overrides the individual component thermal limits. • Individual constraint per component. Select this option to automatically consider each component’s unique thermal rating. Note, the thermal rating for each component is determined by the field Max Loading within the Tie Open Point Optimization page of each component. 3. Optional: Choose to enable or disable the option Consider Voltage Constraints. If this option is enabled then each terminal in the system is checked against the Lower and Upper limit of allowed voltage. If a particular open point causes a voltage violation, then such an open point cannot be considered as “optimal". There are two options for configuring the upper and lower voltage limits: • Global constraints for all terminals (absolute value). If you choose this option then you must enter an upper and lower voltage limit in the two corresponding fields within this dialogue box. • Individual constraint per terminal. If you choose this option, then each terminal has a unique voltage limit which is assigned on the Tie Open Point Optimization page of each terminal (note that this excludes Substation internal nodes). 4. Optional: Choose to enable or disable the option Consider Voltage Drop / Rise. If this option is enabled then each feeder in the system is checked against the Maximum Voltage Drop / Rise. If a particular open point causes a voltage violation, then such an open point cannot be considered as “optimal". There are two options for configuring the maximum voltage drop / rise limits: • Global constraints for all feeders (percent). If you choose this option then you must enter the Maximum Voltage Drop and Maximum Voltage Rise in the two corresponding fields within this dialogue box. • Individual constraint per feeder. If you choose this option, then each feeder has a unique voltage drop / rise limit which is assigned on the Tie Open Point Optimization page of each feeder. 5. Choose the ignore all constraints for... option. You can use these options to optionally ignore constraints where the nominal voltage is above or below user-defined thresholds entered here. This can be useful for example to exclude all LV systems (say less than 1 kV) from the constraints identification process as it may be acceptable to have these systems outside the “normal" range. How to configure the Advanced Options The options in the Advanced page can generally be left on default values. The options are described as follows: • Switches to be optimized. These options configure the switches / elements considered by the optimization procedure. – All switches. All switches will participate in the optimization. – Selected switches. Only the selected switch types will participate in the optimization. For example, if “Circuit-Breaker" and “Load-Breaker-Switch" are ticked, then both circuit breakers and load breakers will be considered by the optimization. The switch type is defined on the switch element “Basic Data" page. Similar to Switch type, only the selected control types will participate in the optimization. The control type is defined in switch element “Reliability" page in the “Sectionalizing" field. Switches are considered in the optimization only when its switch type AND the control type satisfies the selected settings.

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35.5. BACKBONE CALCULATION – Assume each edge element is switchable. If selected, lines that do not have a switch can also be switchable (either out of service or in service). • Maximum number of outer loops. This option controls the maximum number of outer loops which is the total number of times the optimization procedure will be repeated when searching for an optimal solution. • Maximum change in system losses. This option determines the threshold above which a change in open point is considered. If the reduction in losses is below this threshold, the iteration will stop. • Constraint Priority options can be selected for the relevant constraints. For example, consider the following scenario: – The TOPO calculation is to consider Global Thermal constraints, with the Max. thermal loading of components set to 100 %, and Global Voltage Constraints with a Lower limit of 0.90 pu. – The constraint priorities for loading constraint is set to 1, and for voltage lower limit is set to 3. – In the current configuration, a line is loaded to 102 % of rating. – Shifting the open point causes the voltage at a terminal on an adjacent feeder to decrease 5 % below 0.90 pu (i.e. 0.855 pu). – As a result of the priorities, the thermal loading deviation will be “penalized" to a greater extent than the voltage deviation, and the open point will change, despite the resultant voltage deviation. How to configure Reliability Options If Optimization of Reliability Indices is selected, the user may select between optimization of SAIFI or EPNS indices on the Reliability page. Where: • SAIFI (System Average Interruption Frequency Index) in units of [1/C/a], indicates how often the average customer experiences a sustained interruption in one year. Note that the number of customers at each load should be defined on the Reliability page. • EPNS (Expected Power Not Supplied) is in units of [MW]. Multiplying EPNS by the study duration gives the expected energy not supplied. Contingency definitions can be optionally considered for Busbar / terminals, Lines / Cables, and Transformers. If Cost Optimization (Losses + Reliability) is selected, Costs for Losses and Interruption costs per customer should be defined, as these are used in the Objective Function calculation to determine the network configuration that optimizes both Losses and Reliability.

35.5

Backbone Calculation

This section describes the Backbone Calculation command (ComBbone) dialogues and presents an example calculation. To run a Backbone Calculation, either: • Select the Backbone Calculation icon under Distribution Network Tools as shown in Figure 35.1.1. • From the Data Manager select and then right-click previously defined feeders and click Calculate → Backbone Calculation.... • From the main menu, select Calculation → Distribution Network Tools→ Backbone Calculation. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 35. DISTRIBUTION NETWORK TOOLS The Backbone Calculation is used to determine the main paths between adjacent feeders connected via open points, that may serve to restore lost load in case of failures inside a feeder. The command creates objects in the Network Data folder (ElmBbone) with the Backbones constituent network elements. This simplifies visualization of the main path(s) between feeder(s), particularly in large distribution networks where the main paths may not be apparent from the single line diagram. Backbone objects are created for all feeders or a user-defined set of feeders based on path load, crosssection, network structure, or scoring method criteria. The command can optionally consider existing remote controlled switches at open points, and the availability of connections to alternative transformers or substations when creating Backbones. From the Backbone dialogue, the Backbone contents (elements) can be viewed, marked in the graphic, and checked (see example in Section 35.5.4). The Check Backbone button is used to verify that the backbone object still defines a valid inter-feeder path matching its calculated parameters.

35.5.1

Basic Options Page

Generate backbones Specify all feeders or a user-defined set of feeder/s for the Backbone Calculation. Calculation based on: • Path load: Backbones are determined based on the MVA load on the paths between adjacent feeders. – (Optional) specify the max. number of backbones per feeder. – Optionally select to Report results to the output window, including details of backbone open points. – Pointer to load-flow command (note for balanced calculations only). Note: For calculations based on path load, feeder is supposed to be operated radially must be selected on the Basic Options page of the Feeder/s selected for the Backbone calculation, as well as all connected feeders. • Cross section: Backbones are determined based on the cross-section of lines/cables connecting adjacent feeders. – (Optional) specify the max. number of backbones per feeder. – Choose to determine backbone using either the mean cross section of lines in the path or the minimum cross section in path. – Optionally select to Report results to the output window, including details of backbone open points, and minimum and mean cross-section. • Network structure: Backbones are determined based on the network structure. If none of the options are selected, Backbones are calculated for all feasible inter-feeder paths. – (Optional) create backbones only if path leads to different substation. – (Optional) create backbones only if path leads to different HV/MV-transformer. – (Optional) create backbones only if tie open point is remote-controlled (as specified on the Reliability page of each switch). – Optionally select to Report results to the output window, including details of backbone open points. • Scoring method: Backbones are determined using a scoring algorithm based on the restoration ability of the adjacent feeder. Scoring method settings are entered on the Scoring Settings page. 814

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35.5. BACKBONE CALCULATION – (Optional) specify the max. number of backbones per feeder. – Optionally select to Report results to the output window, including details of backbone open points, and loading/voltages of limiting elements. – Pointer to load-flow command (note for balanced AC calculation only). Note: For calculations based on scoring method, feeder is supposed to be operated radially must be selected on the Basic Options page of the Feeder/s selected for the Backbone calculation.

35.5.2

Scoring Settings Page

If scoring method is selected on the Basic Options page, enter scoring settings on the Scoring Settings page. Backbones are determined based on the restoration ability of every inter-feeder path using Topology, Loading violation, and Voltage violation criteria. For each criteria satisfied, the path receives the entered number of points. The path with the greatest number of points is the “winning" path. Topology scoring Define scoring settings for Topology scoring criteria: • Path leads to different substation. • Path leads to different HV/MV-transformer. • Tie open point is remote controlled. • Greater than a specified number of remote-controlled switches on path. A path to another Feeder receives the entered number of points if more (closed) remote-controlled switches than the entered number are on the path of the Backbone contained in the initial feeder. Loading violation scoring Assign Points for loading violations based on individual loading constraints or global loading constraints. If no element is overloaded, the calculation assigns the specified number of points. If global loading constraints is selected, then Max. Loading should also be defined. Define scoring settings for Loading violation scoring criteria: • Restoring transformer (restoration mode). Consider a path from initial “feeder A" to “feeder B". “Feeder A" is de-energized and the connection to “feeder B" via the tie open point is closed. A load flow is calculated in this so-called restoring mode and the entered number of points is assigned if the supplying HV/MV-transformer is not overloaded. • On backbone of restoring feeder (normal mode). Consider a path from initial “feeder A" to “feeder B". A load flow is calculated (in so-called normal mode) and the entered number of points is assigned if no element on the potential backbone path contained in “feeder B", the restoring feeder is overloaded in the base case. • On complete backbone (restoration mode). Consider a path from initial “feeder A" to “feeder B". “Feeder A" is de-energized and the connection to “feeder B" via the tie open point is closed. A load flow is calculated in this so-called restoring mode and the entered number of points is assigned if no element on the potential backbone path is overloaded. • In complete feeder (restoration mode). Consider a path from initial “feeder A" to “feeder B". “Feeder A" is de-energized and the connection to “feeder B" via the tie open point is closed. A load flow is calculated in this so-called restoring mode and the entered number of points is assigned if no element in the complete resulting feeder is overloaded (not only on the backbone as for the previous option). DIgSILENT PowerFactory 15, User Manual

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CHAPTER 35. DISTRIBUTION NETWORK TOOLS Voltage violation scoring Define scoring settings for voltage violation criteria based on individual voltage drop/rise constraints or global voltage drop/rise constraints. If global voltage drop/rise constraints is selected, then Max. drop and Max. rise should also be defined. If no voltage limits are violated, the calculation assigns the specified number of points. • On backbone of restoring feeder (normal mode). Consider a path from initial “feeder A" to “feeder B". A load flow is calculated (in so-called normal mode) and the entered number of points is assigned if no terminal on the potential backbone path contained in “feeder B" violates its voltage drop constraint and voltage rise constraint. • On complete backbone (restoration mode). Consider a path from initial “feeder A" to “feeder B". “Feeder A" is de-energized and the connection to “feeder B" via the tie open point is closed. A load flow is calculated in this so-called restoring mode and the entered number of points is assigned if no terminal on the potential backbone path violates its voltage drop and rise constraint. • In complete feeder (restoration mode). Consider a path from initial “feeder A" to “feeder B". “Feeder A" is de-energized and the connection to “feeder B" via the tie open point is closed. A load flow is calculated in this so-called restoring mode and the entered number of points is assigned if no terminal in the complete resulting feeder violates its voltage drop and rise constraint (not only on the backbone as for the previous option).

35.5.3

Tracing Backbones

When a Backbone is calculated, it always contains a connection to another Feeder via a tie open point. In the worst case of an outage close to the feeding point of the initial feeder, the initial feeder is deenergized by opening its feeding switch and restored by the second Feeder via the tie open point. These restoration steps can be simulated for an existing Backbone using the Backbone trace functionality. The trace buttons are located beside the ComBbone command, and can also be accessed via the main menu Calculation → Distribution Network Tools→ Start trace....

35.5.4

Example Backbone Calculation

Consider a case where there are two parallel feeders with multiple open-points. A Backbone calculation is conducted based on a criteria of minimum cross section in path, and with the Max. number of backbones per feeder set to “1". Backbone objects are created within the Network Data folder. To highlight Backbones, from the main menu select View → Diagram Colouring (or select the Diagram Colouring icon). Under 3. Other select Topology Feeders. Click on Colour Settings, and on the Feeders page select Highlight backbones. Figure 35.5.1 shows the result, where the path through “Open Point 2" is highlighted as a result of the cross section of conductors in this path. Refer to section 35.5.3 for details of how to trace the Backbone restoration steps.

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35.6. OPTIMAL CAPACITOR PLACEMENT

Figure 35.5.1: Example Backbone Calculation

35.6

Optimal Capacitor Placement

Optimal Capacitor Placement (OCP) is an automatic algorithm that minimizes the cost of losses and voltage constraints (optional) in a distribution network by proposing the installation of new capacitors at terminals along the selected feeder/s. The optimal size and type of capacitor is selected from a list of available capacitors entered by the user. The algorithm also considers the annual cost of such capacitors and only proposes new capacitors for installation when the reduction of energy loss and voltage constraint costs exceeds the annual cost of the capacitor (investment, maintenance, insurance etc). To access the OCP tool, select the OCP toolbar from the toolbar selection window as illustrated in Figure 35.6.1.

Figure 35.6.1: Optimal Capacitor Placement Tools

The buttons in the OCP toolbar are as follows: • The main Optimal Capacitor Placement command is started with the Calculate Optimal Capacitor Placement icon ( ). The command and the various user-defined options are described in detail in Sections 36.2.1 to 35.6.6. • After a successful optimization, the list of nodes (terminals) where capacitors are proposed for DIgSILENT PowerFactory 15, User Manual

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CHAPTER 35. DISTRIBUTION NETWORK TOOLS installation can be accessed by selecting the Show nodes with New Capacitors icon (

).

• Following a successful OCP, the list of proposed capacitors can be accessed with the Show New Capacitors icon ( ). • The Remove previous solution icon ( a previous OCP routine.

) deletes the results (removes all placed capacitors) from

• To list all results from the OCP in a ASCII text report printed to the output window use the Output Calculation Analysis icon ( ). The report also displays the original system losses and voltage constraint costs and such costs after the installation of the proposed capacitors.

35.6.1

OCP Objective Function

The OCP optimization algorithm minimizes the total annual network cost. This is the sum of the cost of grid losses, the cost of installed capacitors, and optionally the fictitious penalty cost of voltage violations:

𝑇 𝑜𝑡𝑎𝑙𝐶𝑜𝑠𝑡𝑠 = 𝐶𝐿𝑜𝑠𝑠𝑒𝑠 +

𝑚 𝑛 ∑︁ ∑︁ (𝐶𝐶𝑎𝑝𝑖 ) + (𝐶𝑉 𝑜𝑙𝑡𝑉 𝑖𝑜𝑙𝑖 ) 𝑖=1

(35.1)

𝑖=1

Where: • 𝐶𝐿𝑜𝑠𝑠𝑒𝑠 is the annual cost of grid losses (i.e. including the grid losses, not only the feeder/s for which the optimal capacitor placement is performed). Essentially, this is the 𝐼 2 𝑅 loss of all elements in the network. • 𝐶𝐶𝑎𝑝𝑖 is the annual cost of a capacitor (investment, maintenance, insurance), as entered by the user in the list of possible capacitors. m is the total number of installed capacitors. • 𝐶𝑉 𝑜𝑙𝑡𝑉 𝑖𝑜𝑙𝑖 corresponds to a fictitious cost used to penalize a bus (terminal) voltage violation. 𝑛 is the total number of feeder terminals with voltage violations. Note that if the OCP is not able to reduce the Total Costs by installation of a capacitor/s, the following message will be reported: DIgSI/err - Costs can not be reduced with the given "Available Capacitors" Evaluating the Voltage Violation Cost As there is no ’real’ cost for a voltage violation, if the user wants to consider voltage violations as part of the OCP algorithm, they must assign a ’fictitious’ cost for such violations. The voltage violation cost is calculated based on the user specified voltage limits and penalty factors. The voltage limits are defined in the ’Basic Options’ tab of the OCP command dialogue (’vmin’ and ’vmax’ parameters, see Section 36.2.1: Basic Options Page). The penalty factors are defined in the ’Advanced Options’ tab of the same command (’weight’ and ’weight2’ fields, see Section 35.6.6: Advanced Options Page). The penalty values are applied for voltages inside the admissible voltage band (parameter ’weight’: Penalty Factor 1) and for voltages outside the admissible band (parameter ’weight2’: Penalty Factor 2). There are two possible situations for a terminal voltage and the calculation for the fictitious voltage violation cost is slightly different for each situation. The two situations are explained as follows: 1. In situation one, the voltage 𝑈 of a terminal is within the allowed voltage band (between vmax and vmin) but deviates from the nominal voltage of 1 p.u. The penalty cost is calculated as: 𝐶𝑉 𝑜𝑙𝑡𝑉 𝑖𝑜𝑙 = 𝑤1 · ∆𝑈 818

(35.2)

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35.6. OPTIMAL CAPACITOR PLACEMENT where: ∆𝑈 is the absolute deviation from the nominal voltage in p.u. (∆𝑈 = |𝑈 − 𝑈𝑛 |). 𝑤1 is the penalty factor (parameter ’weight’) inside the admissible voltage band in $/% from the ’Advanced Options’ tab. 2. For situation two, the voltage 𝑈 is outside the allowed voltage band (greater than vmax or less than vmin) and the penalty cost is calculated as: 𝑈 > 𝑈𝑛 + ∆𝑈𝑚𝑎𝑥 , if voltage is higher than max. limit: 𝐶𝑉 𝑜𝑙𝑡𝑉 𝑖𝑜𝑙 = 𝑤2 · (∆𝑈 − ∆𝑈𝑚𝑎𝑥 ) + 𝑤1 · ∆𝑈 or 𝑈 < 𝑈𝑛 − ∆𝑈𝑚𝑖𝑛 , if voltage is lower than min. limit: 𝐶𝑉 𝑜𝑙𝑡𝑉 𝑖𝑜𝑙 = 𝑤2 · (∆𝑈 − ∆𝑈𝑚𝑖𝑛 ) + 𝑤1 · ∆𝑈 where • ∆𝑈 is the absolute deviation from the nominal voltage 𝑈𝑛 in p.u. • 𝑈𝑛 + ∆𝑈𝑚𝑎𝑥 is the higher voltage limit in p.u. • 𝑈𝑛 − ∆𝑈𝑚𝑖𝑛 is the lower voltage limit in p.u. • 𝑤1 is the penalty factor (parameter ’weight’) for voltage inside the admissible voltage band in $/% from the ’Advanced Options’ tab. • 𝑤2 is the penalty factor (parameter ’weight2’) for voltage outside the admissible voltage band in $/% from the ’Advanced Options’ tab. The algorithm can be summarized in as follows: • If the voltages are inside the admissible band the penalty cost applied is equal to 𝑤1 · ∆𝑈 • If the voltages are outside the admissible band the penalty cost applied is equal to the penalty inside the band (𝑤1 · ∆𝑈 ) plus the factor 𝑤2 · (∆𝑈 − ∆𝑈𝑙𝑖𝑚 , with ∆𝑈𝑙𝑖𝑚 being either the maximum or the minimum limit value of the admissible band. Figure 35.6.2 illustrates the concept of the voltage band violation cost.

Figure 35.6.2: Fictitious cost assigned by voltage band violations

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35.6.2

OCP Optimization Procedure

To find the optimal configuration of capacitors, PowerFactory applies the following steps: • First a sensitivity analysis determines the ’best’ candidate terminal; This involves evaluating the impact on the total cost (Losses + Voltage Violations) by connecting the largest available capacitor from the user-defined list of capacitors to each target feeder terminal. At this stage the cost of the largest capacitor is excluded. • Terminals are ranked in descending order of total cost reduction. The terminal that provides the largest cost reduction becomes the ’best’ candidate terminal for a ’new’ capacitor. • The optimisation routine then evaluates the cost reduction at the candidate terminal using each available capacitor from the user-defined list including the cost of each capacitor. The ’best’ capacitor is the one that reduces the cost the most when also considering the annual cost of that capacitor. • Repeat step one but any terminals that have previously been selected as candidates for capacitor installation are not included in the ranking of candidate terminals. The algorithm stops when all terminals have had capacitors installed, or the installation of capacitors cannot reduce costs any further. Note: If Load Characteristics are considered, then the above algorithm will be completed for every independent load state. See Section 35.6.5 for how the load states are determined.

35.6.3

Basic Options Page

Figure 35.6.3: Basic Options page for Optimal Capacitor Placement

Feeder

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35.6. OPTIMAL CAPACITOR PLACEMENT Here the target feeder for the optimum capacitor placement is selected. The feeder is a special PowerFactory element that must be created by the user before it can be selected in this dialogue (for information about feeders refer to Chapter 13: Grouping Objects 13.5 (Feeders)). Method • Optimization; This option calculates the optimal placement for capacitors using the methodology described in Section 35.6.2. The output of the analysis is printed to the output window and any new capacitors are connected to the target terminal/s if the ’Solution Action’ - ’Install capacitors’ is selected. • Sensitivity Analysis; Performs the sensitivity analysis that ranks the candidate terminals according to their impact on the total loss cost excluding the capacitor cost. The output is presented in the Output Window. This option provides a quick indication of the most effective place for a single capacitor. No capacitors are installed if this option is selected. Network Representation Here either a ’Balanced, positive sequence’ or a ’Unbalanced’ network representation can be selected. The Load-flow command referenced below these radio buttons is automatically adjusted to the correct calculation method based on this selection. Constraints Here the voltage constraint limits (upper and lower) can be entered, along with a limitation for the ’Total Reactive Power of all Capacitors’ that can be added by the Optimal Capacitor Placement tool. The total reactive power of all capacitors includes all existing capacitors along the feeder plus any more capacitors proposed by the optimization tool. Note: The voltage constraints are meaningless if penalty factors for deviations outside of the nominal range are not entered as discussed in detail in Section 35.6.1: OCP Objective Function.

Energy Costs The energy cost ($/kWh) can be entered manually or taken from an External Grid. Note, if more than one External Grid exists in the network, the algorithm takes the first External Grid by database ID. The calculation of the cost of the network losses is as follows:

𝑇 𝐶 = 𝑀 𝐶 × 8760 × 𝐿

(35.3)

where: 𝑇 𝐶 is the total cost per annum in $; 𝑀 𝐶 is the energy cost of losses in $/kWh; and 𝐿 is the total losses in kW. Note that if characteristics are applied to the loads and the analysis uses the option ’Consider Load Characteristics’ (see Section 35.6.5), then the losses calculation becomes a summation over each time state considered. Note: The default energy cost units are $/kWh. However, this can be changed to Euro or Sterling (£) via the project settings from the main menu bar. Edit → Project. . . Project Settings→ Input Variables tab→ Currency Unit.

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CHAPTER 35. DISTRIBUTION NETWORK TOOLS Solution Action • Report only (do not modify network); The result of the optimisation is a report to the Output Window only, no modifications are made to the network model. • Install capacitors (modify network). If this option is chosen, the capacitors that the optimization proposes for the network will be automatically installed. However, note that the single line diagram is not automatically updated, only the network model database. To draw the installed capacitors in the SLD the option must be selected in the Advanced Options page (see section 35.6.6). The placed capacitors can be also visualized on the Voltage Profile Plot of the Feeder, see (Viewing results on the Voltage Profile Plot) in Section 35.6.7.

35.6.4

Available Capacitors Page

Figure 35.6.4: Available Capacitors page for Optimal Capacitor Placement

On this page, the user defines the available capacitors for the OCP command. One capacitor is entered per row. To add a new capacitor, right-click within any cell and select the option ’Insert Rows’, ’Append Rows’ or ’Append n Rows’. The following fields are mandatory for each row: • Ignored; If this option is checked, then the capacitor specified in this row will be ignored by the OCP command. • Q per Step Mvar; Here the nominal reactive power of the capacitor in Mvar per step is specified. • Switchable; If this option is enabled then the algorithm can use a capacitor with multiple steps. • Max. Step; If the ’Switchable’ option is enabled, then this option specifies the maximum number of steps available to the optimisation algorithm. The maximum available reactive power is therefore Max. Step * Q per Step Mvar. • Technology; Specifies whether the capacitor is Three-phase or Single-phase. 822

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35.6. OPTIMAL CAPACITOR PLACEMENT • Cost; Important. This is the total cost of the capacitor bank per annum. This is a critical parameter for the OCP command as the capacitor will only be installed if the losses offset by its installation are greater than the annual cost of the capacitor. Note: It is theoretically possible to force the installation of a particular capacitor at an optimal location on a feeder by defining a very low cost for the capacitor, and limiting the number of capacitors to say, one.

Available Capacitors • Allow use of each capacitor multiple times; This is the default option and it means that every capacitor in the list can be used at more than one feeder terminal (multiple times). • Use each capacitor only once; If this option is enabled then each capacitor can only be placed at one terminal along the target feeder. Treatment of 3-phase capacitors This option allows the specification of the ’technology’ type for 3phase capacitors. This option is only available when the ’Network Representation’ is set to ’Unbalanced’ in the Basic Options page.

35.6.5

Load Characteristics Page

Figure 35.6.5: Load Characteristics Page for Optimal Capacitor Placement

If load characteristics are to be considered by the optimization algorithm, then the option ’Consider Load Characteristics’ should be enabled on this page. Load States Two options are available: DIgSILENT PowerFactory 15, User Manual

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CHAPTER 35. DISTRIBUTION NETWORK TOOLS 1. ’Use existing Load States’; If this option is selected then the system load state that is active in the system (the load state observed as a result of a single load-flow at the current point in time) will be used as the load state for the optimization algorithm. For example, if there is a 1 MW load with a active characteristic that gives the current load value of 0.6 MW, then the load used for the optimization will be 0.6 MW, not 1 MW. 2. ’Create Load States’; If this option is selected then PowerFactory automatically discretises all load characteristics into a number of ’states’ using a sophisticated algorithm. The algorithm iterates through every hour of the selected time period to determine the number of unique operating load states that exist. Every operating state is assigned a probability based on the number of times that it occurs and this probability is used to determine the cost of losses for each state.

35.6.6

Advanced Options Page

Figure 35.6.6: Advanced Options page for Optimal Capacitor Placement

Candidate Buses • All terminals in feeder; If this option is selected, every terminal in the feeder is considered as a possible candidate for a ’new’ capacitor. • Percentage of terminals in feeder; Selecting this option and entering ’x’ percent for the parameter means the optimization algorithm will only consider ’x’ percent of the feeder terminals as targets (candidates) for ’new’ capacitors. The ranking of terminals is according to the Sensitivity Analysis as described in Section 35.6.2. Max. Number of Iterations This parameter determines the maximum number of iterations of the optimization algorithm before it automatically stops. As a maximum of one capacitor is placed per iteration, this can effectively limit the total number of capacitors that can be placed by the optimization routine. 824

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35.6. OPTIMAL CAPACITOR PLACEMENT Max. Execution Time This parameter specifies the maximum time the optimisation routine can run before it is automatically interrupted. Penalty Factors for Voltage Deviation • Factor for Deviation from 1 p.u (weight); This parameter is used to determine the total ’fictitious cost’ for terminals deviating from 1 p.u. The cost is applied to each phase of the terminal. For example, if a three phase terminal voltage is measured at 0.95 p.u for each phase and the ’fictitious cost rate’ is $10,000/% then the total cost of this deviation is $150,000 (5% * $10,000/% * 3). Note: If no penalty costs are to be applied within the admissible band, this factor should be set to zero. If this value is greater than zero, the program will add costs to all terminals with voltage different than 1.0 p.u.

• Additional Factor outside range [vmin, vmax] (weight2); This parameter can be used to apply an additional weighting factor to the first deviation factor when the terminal voltage falls outside the voltage limits defined on the ’Basic Options’ page. The factor is cumulative, so using the previous example and a additional factor of 20,000/% with a vmin of 0.975, the fictitious cost becomes $300,000 (5% * $10,000/% + 2.5% * $20,000/%) * 3. Note: The values for the two voltage penalties ’weight’ and ’weight2’ should be carefully chosen because the target optimization function is a sum of three objective functions (losses, capacitor cost and voltage deviation cost). If the voltage weights are too high, the algorithm might not consider the other two objectives. Likewise, if they are very low, the algorithm may not consider voltage violations at all.

Print report after optimisation The automatic printing of the optimisation results can be disabled by unchecking this option. Draw the installed capacitors This option draw the installed capacitors in the Single Line Diagram when checked.

35.6.7

Results

The last three OCP tool-bar buttons give access to the optimization results. Show Nodes with New Capacitors When pressing the Show Nodes with New Capacitors icon ( ), after a successful optimization is complete, a list appears of all terminals where capacitors are proposed for installation. Show New Capacitors Pressing the Show New Capacitors icon (

) shows a list of proposed new capacitors.

Output Calculation Analysis This Output Calculation Analysis icon ( and the final optimization procedure.

) generates a report with the results of the sensitivity analysis

Viewing results on the Voltage Profile Plot DIgSILENT PowerFactory 15, User Manual

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CHAPTER 35. DISTRIBUTION NETWORK TOOLS Following a successful optimization, the ’new’ capacitors can be visualized on the voltage profile plot of the feeder. To enable this, navigate to the voltage profile plot display after the optimization and click the button. An example of such a plot showing the placed capacitors is shown in Figure 35.6.7. rebuild

Figure 35.6.7: Voltage profile plot showing the new capacitors after an Optimal Capacitor Optimisation.

Removing Capacitors Placed by the Optimal Capacitor Placement Routine The capacitors placed by the OCP command can be removed at any time after the analysis has been completed by using the Remove previous solution icon ( ). This button is like an ’Undo’ for the ’Optimal Capacitor Placement’.

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Chapter 36

Cable Sizing 36.1

Introduction

The chapter presents the PowerFactory tools for sizing cables, according to the Cable Reinforcement method and the International Standards method (IEC 60364-5-52, NF C15-100, BS 7671, NF C13-200). • International Standards Method. Either verify the suitability of the assigned line Types or recommend new line Types according to the selected International Standard. • Cable Reinforcement Method. Either verify the suitability of the assigned line Types or recommend Types according to user-defined voltage, thermal, and short-circuit constraints. The optimization may be performed on a network model without any cable/line types yet defined, based on the load and power flows in the active study case. To access the Cable Sizing command (ComCabsize), select the Change Toolbox icon ( Tools, and then select the Cable Sizing icon ( ), as illustrated in Figure 36.1.1.

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), Additional

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Figure 36.1.1: How to access the Cable Sizing command

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36.2. CALCULATION OPTIONS

36.2

Calculation Options

36.2.1

Basic Options Page

Figure 36.2.1: Basic Options page for Cable Reinforcement Optimization

Method Select to execute the Cable Sizing command based on either: • International Standards applicable to low-voltage networks up to 1kV, IEC 60364-5-52, NF C15100 and BS 7671, or applicable to medium-voltage networks 1kV to 33kV, NF C13-200. Refer to the standards for further details. • Cable Reinforcement with user-defined types and constraints. Note: Standards tables for cable ampacity, cross-section, derating factors, and impedances are stored in the Database → System→ Modules→ Cable Sizing folder.

Further details are given in , too. Lines/Feeders • If Method is set to International Standards, specify the Line/s for the Cable Sizing analysis. • If Method is set to Cable Reinforcement, specify the Feeder/s for the Cable Reinforcement analysis. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 36. CABLE SIZING Mode • If Verification is selected, then the command will assess the suitability of the existing line types: – For the International Standards Method, the command will verify the suitability of the line/cable in accordance with the selected standard. – For the Cable Reinforcement Method, the command will verify the suitability of the line/cable in accordance with the selected constraints and / or network consistency criteria. At least one of Thermal Loading Limits, Consider Voltage Drop Per Terminals, Consider Voltage Drop Along Feeder, Short Circuit Loading Limits, and Network Consistency must be selected. • If Recommendation is selected: – For the International Standards Method, the command will create new cable types for the low voltage and medium voltage grids according to the selected international standard. The cable derating factor will be set based on the installation method, specified on the Line Elements Cable Sizing page. Types will be created in the target folder, or if no folder is selected, inside the Equipment Type Library. – For the Cable Reinforcement Method, the command will recommend line/cable types for those lines without Types yet defined, and those that cause violations of the specified constraints. Reference to a folder that contains the overhead / cable types to be considered should be provided. This may be a global library, however it is recommended that the available types be stored in a local project library. PowerFactory will automatically select the lines/cables with a voltage rating suitable for the line element. Note: Line/cable cost data in $/km is entered on the Cable Sizing page of the line type.

Network Representation Balanced, positive sequence or Unbalanced network representation can be selected. The Load-flow command referenced below these radio buttons is automatically adjusted to the appropriate calculation method based on this selection. Load Flow, Short Circuit These are a references (pointers) to the load-flow command and short-circuit command (if applicable) used by the optimization algorithm. For a Cable Reinforcement calculation in Verification Mode, the user can optionally consider Short Circuit Loading Limits. The Short Circuit Calculation command will also be automatically adjusted based on the calculation method selected. However, if switching between Balanced and Unbalanced representation, the user should ensure that the short-circuit calculation is set to the required fault type.

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36.2. CALCULATION OPTIONS

36.2.2

Constraints Page

Figure 36.2.2: Constraints page for Cable Reinforcement Optimization

Constraints options are only applicable if Cable Reinforcement is selected on the Basic Options page. Thermal Loading Limits Optionally select to consider Thermal Loading Limits. There are two options for thermal constraints: • Global Constraints For All Lines. This is the default option, where individual component thermal limits are ignored. If enabled, a maximum thermal loading percentage must be entered in the Maximum Thermal Loading field. • Individual Constraint Per Line. Select this option to automatically consider each component’s unique thermal loading limit. Note, the thermal rating is specified in the field Max Loading within the Load Flow tab of each line. Consider Voltage Drop Per Terminals Optionally select to Consider Voltage Drop Per Terminals. There are two options for terminal voltage drop constraints: • Global Constraints For All Terminals (absolute value). If selected, a lower voltage limit must be entered in the Lower Limit of Terminal Voltage field. • Individual Constraint Per Terminal. Note, the voltage limit is specified in the Load Flow tab of each terminal. Consider Voltage Drop Along Feeder For balanced calculations, optionally select to Consider Voltage Drop Along Feeder. The voltage drop DIgSILENT PowerFactory 15, User Manual

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CHAPTER 36. CABLE SIZING is calculated as the absolute voltage difference between the source terminal of the feeder and the final terminal of the feeder. There are two options for feeder voltage drop constraints: • Global Constraints For All Feeders. If this option is selected, then the maximum voltage drop must be entered in the Maximum Voltage Drop field. • Individual Constraint Per Feeder. Note, the maximum voltage drop is specified in the Load Flow tab of each feeder. Short Circuit Loading Limits When the Mode is set to Verification, optionally select to consider Short Circuit Loading Limits. Constraints can be entered in the Maximum Loading field as a percentage of the rated short-circuit current in the Type data for lines and terminals, etc. Note: Depending on the system topology, on the loads and on the length of the feeder, it might not be possible to avoid voltage drop violations of some terminals or feeders. This can be mitigated by the installation of a capacitor/s during a post-processing optimization. See Section 35.6: Optimal Capacitor Placement.

36.2.3

Output Page

Figure 36.2.3: Output options page for Cable Reinforcement Optimization

Output Various output options for the optimization results are possible. • Report Only : Any new line types are listed in a pre-defined report displayed in the Output Window. 832

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36.2. CALCULATION OPTIONS • Modification of Cables Type in the Existing Network : If this option is selected, the Report will be generated and the optimization routine will update the network model with the proposed types. Note that this option is only available when the Mode is set to Recommendation on the Basic Options tab. • Create a New Variation with Recommended Cables: If this option is selected, the Report will be generated and the optimization routine will create a Variation with the proposed modifications. Note that this option is only available when the Mode is set to Recommendation on the Basic Options tab. Report This is a reference (pointer) to the result report output, which details calculation settings, and results of the verification or recommendation. For more information about the result language format see Chapter 17: Reporting and Visualizing Results, Section 17.2. Results This is a reference (pointer) to the results output. It is possible to select an alternative results file. Results are indexed as follows for the Cable Reinforcement method: 0. Initial value - Initial calculation of all parameters of feeder, ComCabsize, lines and terminals. 1. Thermal lines verification - Only those lines variables are written which violate the thermal constraint. 2. Thermal lines recommendation - Only those lines variables are written, for which a new cable type is recommended during thermal recommendation process. The cost of improvement is also written. 3. Thermal lines cannot be solved - Only those lines variables are written, that are unsolvable and still violate thermal constraints after thermal recommendation process. 4. Voltage verification - Only those terminals variables are written which violate voltage constraints. 5. Voltage recommendation - Only those lines variables are written, for which a new cable type is recommended during voltage recommendation process. The cost of improvement is also written. 6. Terminals cannot be solved - Only those terminals variables are written which are unsolvable and still violate voltage constraints after the voltage recommendation process. 7. Consistency verification - Only those terminals variables are written which violate network consistency. 8. Consistency recommendation - Only those lines variables are written, for which a new cable type is recommended during the consistency improvement process. The cost of improvement are also written. 9. Consistency violation - Only those terminals variables are written that are unsolvable and still violate network consistency after the recommendation process. 10. Changed cables - Only those lines variables are written, for which a new cable type is recommended after the complete load flow optimization process. 11. Short-circuit verification - Only those lines variables are written which violate short-circuit constraints. Results are indexed as follows for the International Standards method: 100. Pre-verification results. 101. Post-verification results. 102. Pre-recommendation results. 103. Post-recommendation results. DIgSILENT PowerFactory 15, User Manual

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36.2.4

Advanced Options Page

36.2.4.1

International Standards Method

If International Standards and Recommendation is selected on the Basic Options page, then configure the Advanced Options as follows.

Figure 36.2.4: Advanced Options page for Cable Sizing International Standards Method

Cable Sizing • Define the Safety margin for the cable current capacity in percent. If a non-zero safety margin is entered, a cable with higher capacity is selected. • Optionally select to Set cable electrical parameters according to the IEC 60909 to set cable resistance and reactance parameters from conductor cross-section and material according to the IEC 60909 calculation. • Select whether to Use design parameters of the Cable Sizing command, in which case a new type will be created according to the type design parameters from the command. Or, select to Use design parameters of the assigned cable type, in which case a new type will be created according to the existing line type from its rated values (only current and cross-section values could be different). This is only applicable if the analyzed line has a type assigned. Otherwise, a new type will be created according to the command parameters.

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36.2. CALCULATION OPTIONS 36.2.4.2

Cable Reinforcement Method

If Cable Reinforcement is selected on the Basic Options page, then configure the Advanced Options as follows.

Figure 36.2.5: Advanced Options page for Cable Sizing - Cable Reinforcement Method

Network Consistency This option, if enabled, forces the optimization routine to complete a final “consistency" check of the Line Type rated nominal current based upon one of two criteria: 1. Sum of feeding cables >= Sum of leaving cables; or 2. Smallest feeding cable >= Biggest leaving cable. To explain what is meant by “feeding cable" and “leaving cable" consider the example feeder shown in Figure . This network is defined as a single “feeder" that begins at the “Source" terminal. Consider now “Terminal A". This terminal is supplied by “Line A" and is also connected to two other lines, “Line B" and “Line C". In this case, for “Terminal A", “Line A" is considered as a “feeding cable" and lines B and C as “leaving cables". Considering now “Terminal B", Lines B and C are feeding cables whereas Lines D and E are “leaving cables". “Feeding cables" are defined as those cables with a power flow direction that is into the connecting node. For a radial feeder with no embedded generation, this is generally the cables closest to the beginning of the feeder. All other cables are defined as “leaving cables". In consistency check option 1, the cross sectional area (or nominal current) of the feeding cables are summated and compared with the sum of the cross sectional area (or nominal current) of the leaving cables for each terminal. If the sum of the leaving cables is greater at any terminal then the network is considered non-consistent. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 36. CABLE SIZING For consistency check option 2, the smallest feeding cable is compared with the largest leaving cable for each terminal. If the largest leaving cable is bigger than the smallest feeding cable, then the network is considered non-consistent.

Figure 36.2.6: Example feeder network

Recommended Options Available when Mode is set to Recommendation on the Basic Options tab. • Specify the Max. Voltage Deviation in Type Selection in percent. If "0%" is entered, the rated voltage on the cable type should match the rated voltage of the terminal to which it connects. If a non-zero value is entered, the rated voltage of the cable type can differ by the defined percentage. • Optionally select to Assign Missing Line Types. Note that for low voltage networks (less than 1kV) the line type rated voltage should be equal to 1kV.

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36.2. CALCULATION OPTIONS

36.2.5

Type Parameters

Figure 36.2.7: Type Parameters page for Cable Reinforcement Optimization

If the Method International Standards and Mode Recommendation is selected, configure the cable Type parameters. Cable Type Parameters • Conductor Material. Select either Copper or Aluminium. • Insulation Material. Select either PVC, XLPE, Mineral, Paper, or EPR. Note that paper is valid only for NF C13-200, and Mineral is valid only for 0.5kV and 0.75kV systems and copper conductors). • Cable Cores. Select either multi-core (2 or 3 conductors) or single-core (1 conductor). • With Sheath. Select if the cable has a sheath cover. If mineral insulation is selected and this frame is not checked, it is considered that the cable is bare with a metallic sheath. – Sheath Type. Select metallic or non-metallic. – Sheath Insulation. Select either PVC, XLPE, or EPR. – Armoured Cable. If checked, an armoured cable type will be created, otherwise a nonarmoured cable type is created. – Radial Cable Screen. If checked then each conductor has its own screening. This is valid only for multi-core cables, since single-core cables always have radial screening. – Exposed to touch. For copper conductors with mineral insulation, select if the cable is exposed to touch.

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36.3

Cable Sizing Line Parameters

36.3.1

Cable Sizing Line Type Parameters

Figure 36.3.1: Cable Sizing Line Type parameters

Line Type parameters relevant to the Cable Sizing command are defined on the Cable Sizing page of the Line Type TypLne, which includes a simplified image of the cable. See section 36.2.5 for a description of the parameters.

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36.4. SYSTEM TECHNOLOGY CHECK

36.3.2

Cable Sizing Line Element Parameters

Figure 36.3.2: Cable Sizing Line Element parameters

Line Element parameters relevant to the Cable Sizing command are defined on the Cable Sizing page of the Line Element ElmLne, ElmLnesec. The page includes details of the laying arrangements, installation method, and a simplified image of the cable installation. When the Cable Sizing command is executed, the line derating factor (on the Basic Data page) is updated based on the parameters from this page.

36.4

System Technology Check

The Cable Sizing command performs a system technology check, whereby the technology type of terminals (the number of phases and neutrals) determines the technology type of line types added to line elements: • For balanced networks, terminals, lines, and line types should be 3 phase (see also third point regarding neutrals). • For unbalanced networks, lines and line sections are assumed to have a number of phases equal to the minimum number of phases of the element to which it connects. For example, if a line connects from a 3 phase terminal (phase technology “ABC", as defined on the Terminals Basic Data page) to a 2 phase terminal (phase technology “2PH"), the line element is assumed to be 2 phase. The line type must have the same number of phases. • For lines and line sections, if there is a neutral connection at both ends, the line is assumed to have a neutral, and therefore the line type must have a neutral. If end connections do not have neutrals, or only one end connection has a neutral, the line is considered to not have a neutral.

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36.5

Predefined Laying Methods

Predefined laying methods are provided for the French standards; NF C 15-100 and NF C 13-200. All the predefined methods, which are stored in the folder "Laying Type" of the each corresponding standard in the common folder Database → System→ Modules→ Cable Sizing. In the description tab of the line element (ElmLne) or the line section (ElmLnesec) the user is able to link one of the predefined vectors (IntVec), representing the laying method, using the parameter "Additional Data" (Parameter name:doc_id). Each predefined vector has the name equivalent to the name used in the corresponding standard (i.e. laying type "Air 11" uses the same name as used in the relevant standard, in this case NF C 13-200). By selecting desired laying type, settings on the tab "Cable Sizing" shall be accordingly reset to fit available PowerFactory settings. Parameters as temperature, grouped cables or number of trays/layers should be still defined by the user, otherwise default values shall be used. Following sub-chapters give more detailed overview of the available predefined laying methods.

36.5.1

NF C 15-100 (Tableau 52C) Additional Data (doc_id)

Description

Correction factors

1

1 (IntVec)

Single-core cables in conduit in a thermally insulated wall

*𝑓0 = 0.77, 52K, 52N, 52P

2

2 (IntVec)

Multi-core cables in conduit in a thermally insulated wall

*𝑓0 = 0.7, 52K, 52N, 52P

Laying Method

840

3

3 (IntVec)

3A

3A (IntVec)

4

4 (IntVec)

4A

4A (IntVec)

5

5 (IntVec)

Single-core cables in a conduit on a wooden or masonry wall Multi-core cables in a conduit on a wooden or masonry wall Single-core cables in cable conduit on a wooden or masonry wall Multi-core cables in cable conduit on a wooden or masonry wall Single-core cables in conduit in masonry

52K, 52N, 52P *𝑓0 = 0.9, 52K, 52N, 52P 52K, 52N, 52P *𝑓0 = 0.9, 52K, 52N, 52P 52K, 52N, 52Q

Corresponding IEC method and required PowerFactory settings Air; A; ambient temperature; bunched in air, on surface, embedded or enclosed; number of trays/layers; Air; A; ambient temperature; bunched in air, on surface, embedded or enclosed; number of trays/layers; Air; B; ambient temperature; bunched in air, on surface, embedded or enclosed; number of trays/layers; Air; B; ambient temperature; bunched in air, on surface, embedded or enclosed; number of trays/layers Air; B; ambient temperature; bunched in air, on surface, embedded or enclosed; number of trays/layers; Air; B; ambient temperature; bunched in air, on surface, embedded or enclosed; number of trays/layers; Air; B; ambient temperature; bunched in air, on surface, embedded or enclosed; number of trays/layers;

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36.5. PREDEFINED LAYING METHODS

Laying Method

5A

11

11A

Additional Data (doc_id)

Description

Correction factors

5A (IntVec)

Multi-core cables in conduit in masonry

*𝑓0 = 0.9, 52K, 52N, 52Q

11 (IntVec)

11A (IntVec)

12

12 (IntVec)

13

13E and 13F (IntVec)

14

14E and 14F (IntVec)

16

16E and 16F (IntVec)

17

17E and 17F (IntVec)

18

18 (IntVec)

Multi- or singlecore cables fixed on a masonry or wooden wall Multi- or singlecore cables fixed directly under a wooden or masonry ceiling Multi- or singlecore cables on unperforated tray run horizontally Multi- or singlecore cables on perforated tray run horizontally or vertically Multi- or singlecore cables on brackets or wire mash tray Multi- or singlecore cables on ladders Multi- or singlecore cables suspended from or incorporating a support wire Bare or insulated conductors on insulators

52K, 52N

Air; B; ambient temperature; bunched in air, on surface, embedded or enclosed; number of trays/layers; Air; C; ambient temperature; grouping as single layer on wall, floor or unperforated tray; trefoil formation;

*𝑓0 = 0.95, 52K, 52N

Air; C; ambient temperature; grouping as single layer fixed directly under a wooden ceiling; trefoil formation;

52K, 52N

Air; C; ambient temperature; grouping as single layer on wall, floor or unperforated tray; flat formation;

52K, 52N

Air; E or F; ambient temperature; laid on perforated trays; laid vertical/horizontal

52K, 52N

Air; E or F; ambient temperature; laid on ladders, supports or cleats;

52K, 52N

Air; E or F; ambient temperature; laid on ladders, supports or cleats;

52K, 52N

Air; E or F; ambient temperature; laid on ladders, supports or cleats;

*𝑓0 = 1.21, 52K

Air; G; ambient temperature;

*𝑓0 = 0.95, 52K, 52N, 52P

21

21 (IntVec)

Multi-core cables in a building void

22

22 (IntVec)

Single-core cables in a building void

*𝑓0 = 0.95, 52K, 52N, 52P

22A

22 (IntVec)

Multi-core cables in conduit in a building void

*𝑓0 = 0.865, 52K, 52N, 52P

DIgSILENT PowerFactory 15, User Manual

Corresponding IEC method and required PowerFactory settings

Air; B; ambient temperature, bunched in air, on surface, embedded or enclosed; number of trays/layers; Air; B; ambient temperature, bunched in air, on surface, embedded or enclosed; number of trays/layers; cable in duct (conduit); Air; B; ambient temperature, bunched in air, on surface, embedded or enclosed; number of trays/layers; cable in duct (conduit);

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Additional Data (doc_id)

Description

Correction factors

23

23 (IntVec)

Single-core cables in cable ducting in a building void

*𝑓0 = 0.95, 52K, 52N, 52P

23A

23 (IntVec)

Multi-core cables in cable ducting in a building void

*𝑓0 = 0.865, 52K, 52N, 52P

24

24 (IntVec)

Single-core cables in cable ducting in a building void

*𝑓0 = 0.95, 52K, 52N, 52Q

24A

24(IntVec)

Multi-core cables in cable ducting in a building void

*𝑓0 = 0.865, 52K, 52N, 52Q

Laying Method

25

842

25 (IntVec)

31

31 (IntVec)

31A

31 (IntVec)

32

32 (IntVec)

32A

32 (Intvec)

33

33 (IntVec)

33A

33 (IntVec)

34

34 (IntVec)

Multi- or singlecore cables in a ceiling void or raised floor Insulated singlecore cables in cable trunking placed horizontally Multi-core cables in cable trunking placed horizontally Insulated singlecore cables in cable trunking placed vertically Multi-core cables in cable trunking placed vertically Insulated singlecore cables in flush cable trunking in the floor Multi-core cables in flush cable trunking in the floor Insulated singlecore cables suspended cable trunking

*𝑓0 = 0.95, 52K, 52N

*𝑓0 = 0.9, 52K, 52N

52K, 52N

Corresponding IEC method and required PowerFactory settings Air; B; ambient temperature, bunched in air, on surface, embedded or enclosed; number of trays/layers; cable in duct (conduit); Air; B; ambient temperature, bunched in air, on surface, embedded or enclosed; number of trays/layers; cable in duct (conduit); Air; B; ambient temperature, bunched in air, on surface, embedded or enclosed; number of trays/layers; cable in duct (conduit); Air; B; ambient temperature, bunched in air, on surface, embedded or enclosed; number of trays/layers; cable in duct (conduit); Air; B; ambient temperature; bunched in air, on surface, embedded or enclosed; Air; B; ambient temperature; bunched in air, on surface, embedded or enclosed; laid horizontally; Air; B; ambient temperature; bunched in air, on surface, embedded or enclosed; laid horizontally;

52K, 52N

Air; B; ambient temperature; bunched in air, on surface, embedded or enclosed;

*𝑓0 = 0.9, 52K, 52N

Air; B; ambient temperature; bunched in air, on surface, embedded or enclosed;

52K, 52N

Air; B; ambient temperature; bunched in air, on surface, embedded or enclosed;

*𝑓0 = 0.9, 52K, 52N

Air; B; ambient temperature; bunched in air, on surface, embedded or enclosed;

52K, 52N

Air; B; ambient temperature; bunched in air, on surface, embedded or enclosed;

DIgSILENT PowerFactory 15, User Manual

36.5. PREDEFINED LAYING METHODS

Laying Method

Additional Data (doc_id)

34A

34 (IntVec)

41

41 (IntVec)

42

42 (IntVec)

43

43 (IntVec)

61

61 (IntVec)

62

62 (IntVec)

63

63 (IntVec)

71

71 (IntVec)

73

73 (IntVec)

73A

73 (Intvec)

74

74 (IntVec)

74A

74 (IntVec)

Description

Correction factors

Corresponding IEC method and required PowerFactory settings

Multi-core cables Air; B; ambient temperature; *𝑓0 = 0.9, suspended cable bunched in air, on surface, 52K, 52N trunking embedded or enclosed; Multi- or singlecore cables in Air; B; ambient temperaconduit in an *𝑓0 = 0.95, ture; bunched in air, on surunventilated ca- 52K, 52N, face, embedded or enclosed; ble channel, laid 52P number of trays/layers; horizontally or vertically Insulated singleAir; B; ambient temperacore cables in 52K, 52N, ture; bunched in air, on surconduit in an open 52P face, embedded or enclosed; or ventilated cable number of trays/layers; channel in the floor Insulated singleAir; B; ambient temperacore cables in an 52K, 52N, ture; bunched in air, on suropen or ventilated 52P face, embedded or enclosed; cable channel in number of trays/layers; the floor Multi- or singlecore cables in *𝑓0 = 0.8, Ground; D; ambient temperconduit or in ca- 52L, 52M, ature; soil type; cable in duct ble ducting in the 52T, 52S (conduit); cables touching; ground Sheathed multi- or single-core cables Ground; D; ambient temper52L, 52M, without armor diature; soil type; cable not in 52R rectly buried in the duct (conduit); ground Sheathed multior single-core caGround; D; ambient temper52L, 52M, bles with armor ature; soil type; cable not in 52R directly buried in duct (conduit); the ground Insulated conductors or single-core 52K Air; A; ambient temperature; cable in mouldings Single-core cables 52K Air; A; ambient temperature; in architrave Multi-core cables in *𝑓0 = 0.9, Air; A; ambient temperature; architrave 52K Single-core cables 52K Air; A; ambient temperature; in window frame Multi-core cables in *𝑓0 = 0.9, Air; A; ambient temperature; window frame 52K Table 36.5.1: NF C 15-100 (Tableau 52C)

*𝑓0 - correction factor of the corresponding installation method (multiplied by the total derating factor), by default 𝑓0 = 1 DIgSILENT PowerFactory 15, User Manual

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Parallel lines with single-core cables Factor 𝑓𝑠 = 0.8 shall be applied in the case when there is an odd number of the parallel lines (𝑛𝑙𝑛𝑢𝑚 >= 3) with single-core cables in the three-phase systems (i.e. 3x3x1). Otherwise the value of 𝑓𝑠 is 1. Parallel lines with multi-core cables Factor 𝑓𝑠 = 0.8 shall be applied in the case when there are more lines in parallel (𝑛𝑙𝑛𝑢𝑚 > 1).

36.5.2

NF C 13-200 (Tableau 52E)

Laying Method

844

Additional Data (doc_id)

Air 3A

Air (IntVec)

3A

Air 5A

Air (IntVec)

5A

11

Description Multi- or singlecore cables in a conduit on a wooden or masonry wall Multi- or singlecore insulated cables in a conduit in a masonry

Correction factors

Corresponding IEC method and required PowerFactory settings

K1, K9

Air; B; ambient temperature; bunched in air, on surface, embedded or enclosed;

K1, K9

Air; B; ambient temperature; bunched in air, on surface, embedded or enclosed;

Multi- or singlecore cables fixed on a masonry or wooden wall

K1, K2, K3

Air 11

Air (IntVec)

Air 11A

Air 11A (IntVec)

Multi- or singlecore cables fixed on a masonry or wooden wall

K1, K4

Air 12

Air (IntVec)

Multi- or singlecore cables on unperforated tray

K1, K2, K3, K7

Air 13

Air 13 E and Air 13 F (IntVec)

Multi- or singlecore cables on perforated tray, vertical or horizontal

K1, K2, K5, K7

Air 14

Air 14 E and Air 14 F (IntVec)

Multi- or singlecore cables on cleats or on a wire mesh (supports) tray

K1, K2, K6, K7

12

Air; C; ambient temperature; exposed to direct sunlight; clearance as touching; grouping as single layer on wall, floor or unperforated tray; Air; C; ambient temperature; clearance as touching; grouping as single layer fixed directly under wooden or masonry ceiling; Air; C; ambient temperature; exposed to direct sunlight; clearance as touching; grouping as single layer on wall, floor or unperforated tray; number of trays/layers; Air; E or F; ambient temperature; exposed to direct sunlight; clearance as touching; laid on perforated trays; Air; E or F; ambient temperature; exposed to direct sunlight; clearance as touching; laid on ladders, supports or cleats; number of trays/layers;

DIgSILENT PowerFactory 15, User Manual

36.5. PREDEFINED LAYING METHODS

Laying Method

Air 16

Additional Data (doc_id)

Air 16 E and Air 17 F (IntVec)

Air 17

Air (IntVec)

17

Air 31

Air (IntVec)

31

Air 32

Air (IntVec)

32

Air 41

Air (IntVec)

41

Air 43

Air (IntVec)

43

Air 45

Air (IntVec)

65

Enterré 60

Enterré (IntVec)

60

Enterré 61

Enterré (IntVec)

61

Enterré 62

Enterré (IntVec)

62

Description

Multi- or singlecore cables on ladders Multi- or singlecore cables suspended from or incorporating a support wire or harness Multi- or singlecore cables in a horizontal conduit on a wooden or masonry wall Multi- or singlecore cables in a vertical conduit on a wooden or masonry wall Multi- or singlecore cables in an closed ventilated cable channels Multi- or singlecore cables in an open or ventilated cable channels Multi- or singlecore cables in conduit in masonry Multi- or singlecore cables in ducts filled with sand Multi- or singlecore cables in conduit or in cable duct Multi- or singlecore sheathed cables laid directly in ground without mechanical protection (armor)

DIgSILENT PowerFactory 15, User Manual

Correction factors

Corresponding IEC method and required PowerFactory settings

K1, K2, K6, K7

Air; E or F; ambient temperature; exposed to direct sunlight; clearance as touching; laid on ladders, supports or cleats; number of trays/layers;

K1, K2

Air; G; ambient temperature; exposed to direct sunlight;

K1, K9

Air; B; ambient temperature; bunched in air, on surface, embedded or enclosed;

K1, K9

Air; B; ambient temperature; bunched in air, on surface, embedded or enclosed;

K1, K10

Air; B; ambient temperature;

K1, K2, K3, K7

K1, K9

Air; C; ambient temperature; exposed to direct sunlight; clearance as touching; grouping as single layer on wall, floor or unperforated tray; number of trays/layers; Air; B; ambient temperature; bunched in air, on surface, embedded or enclosed;

K12, K13, K15

Ground; D; ambient temperature; soil type;

K12, K13, K14, K16, K17

Ground; D; ambient temperature; soil type; depth of laying; number of trays/layers; cables in duct (conduit);

K12, K13, K14, K15

Ground; D; ambient temperature; soil type; depth of laying; cable not in duct (conduit);

845

CHAPTER 36. CABLE SIZING

Laying Method

Enterré 63

Additional Data (doc_id)

Enterré (IntVec)

Description

Correction factors

Corresponding IEC method and required PowerFactory settings

Multi- or singlecore sheathed Ground; D; ambient temper63 cables laid directly K12, K13, ature; soil type; cable not in in ground with me- K14, K15 duct (conduit); chanical protection (armor) Table 36.5.2: NF C 13-200 (Tableau 52E)

Parallel lines with single-core cables Factor 𝑓𝑠 = 0.8 shall be applied in the case when there is an odd number of the parallel lines (𝑛𝑙𝑛𝑢𝑚 >= 3) with single-core cables in the three-phase systems (i.e. 3x3x1). Otherwise the value of 𝑓𝑠 is 1. Parallel lines with multi-core cables Factor 𝑓𝑠 = 0.8 shall be applied in the case when there are more lines in parallel (𝑛𝑙𝑛𝑢𝑚 > 1).

Laying Method

Air 3A

Air (IntVec)

3A

Air 5A

Air (IntVec)

5A

Air 11

Air (IntVec)

11

Description Multi- or singlecore cables in a conduit on a wooden or masonry wall Multi- or singlecore insulated cables in a conduit in a masonry

Correction factors

Corresponding IEC method and required PowerFactory settings

K1, K9

Air; B; ambient temperature; bunched in air, on surface, embedded or enclosed;

K1, K9

Air; B; ambient temperature; bunched in air, on surface, embedded or enclosed;

Multi- or singlecore cables fixed on a masonry or wooden wall

K1, K2, K3

K1, K4

Air 11A

Air 11A (IntVec)

Multi- or singlecore cables fixed on a masonry or wooden wall

Air 12

Air (IntVec)

Multi- or singlecore cables on unperforated tray

K1, K2, K3, K7

Multi- or singlecore cables on perforated tray, vertical or horizontal

K1, K2, K5, K7 (K8)

Air 13

846

*Additional Data (doc_id)

12

Air 13 E 13 F (IntVec)

Air; C; ambient temperature; exposed to direct sunlight; clearance as touching; grouping as single layer on wall, floor or unperforated tray; Air; C; ambient temperature; clearance as touching; grouping as single layer fixed directly under wooden or masonry ceiling; Air; C; ambient temperature; exposed to direct sunlight; clearance as touching; grouping as single layer on wall, floor or unperforated tray; number of trays/layers; Air; E or F; ambient temperature; exposed to direct sunlight; clearance as touching; laid on perforated trays;

DIgSILENT PowerFactory 15, User Manual

36.5. PREDEFINED LAYING METHODS

*Additional Data (doc_id)

Description

Air 14

Air 14 E Air 14 F (IntVec)

Multi- or singlecore cables on cleats or on a wire mesh (supports) tray

K1, K2, K6, K7 (K8)

Air 16

Air 16 E 17F (IntVec)

Multi- or singlecore cables on ladders

K1, K2, K6, K7 (K8)

Laying Method

Air 17

Air (IntVec)

17

Air 31

Air (IntVec)

31

Air 32

Air (IntVec)

32

Air 41

Air (IntVec)

41

Air 43

Air (IntVec)

43

Air 45

Air (IntVec)

65

Enterré 60

Enterré (IntVec)

60

Multi- or singlecore cables suspended from or incorporating a support wire or harness Multi- or singlecore cables in a horizontal conduit on a wooden or masonry wall Multi- or singlecore cables in a vertical conduit on a wooden or masonry wall Multi- or singlecore cables in an closed ventilated cable channels Multi- or singlecore cables in an open or ventilated cable channels Multi- or singlecore cables in conduit in masonry Multi- or singlecore cables in ducts filled with sand

DIgSILENT PowerFactory 15, User Manual

Correction factors

Corresponding IEC method and required PowerFactory settings Air; E or F; ambient temperature; exposed to direct sunlight; clearance as touching; laid on ladders, supports or cleats; number of trays/layers; Air; E or F; ambient temperature; exposed to direct sunlight; clearance as touching; laid on ladders, supports or cleats; number of trays/layers;

K1, K2

Air; G; ambient temperature; exposed to direct sunlight;

K1, K9

Air; B; ambient temperature; bunched in air, on surface, embedded or enclosed;

K1, K9

Air; B; ambient temperature; bunched in air, on surface, embedded or enclosed;

K1, K10

Air; B; ambient temperature; cable in trench (empty/ventilated);

K1, K2, K3, K7

Air; C; ambient temperature; exposed to direct sunlight; clearance as touching; grouping as single layer on wall, floor or unperforated tray; number of trays/layers;

K1, K9

Air; B; ambient temperature; bunched in air, on surface, embedded or enclosed;

K12, K15

K13,

Ground; D; ambient temperature; soil type; cable in trench (filled with sand);

847

CHAPTER 36. CABLE SIZING

Laying Method

Enterré 61

*Additional Data (doc_id)

Description

Correction factors

Corresponding IEC method and required PowerFactory settings

Enterré (IntVec)

Multi- or singlecore cables in conduit or in cable duct

K12, K14, K17

Ground; D; ambient temperature; soil type; depth of laying; number of trays/layers; cables in duct (conduit); installed in masonry;

61

Enterré 62

Enterré (IntVec)

62

Enterré 63

Enterré (IntVec)

63

K13, K16,

Multi- or singlecore sheathed Ground; D; ambient tempercables laid K12, K13, ature; soil type; depth of laydirectly in K14, K15 ing; cable not in duct (conground without duit); mechanical protection (armor) Multi- or singlecore sheathed cables laid diGround; D; ambient temperK12, K13, rectly in ground ature; soil type; cable not in K14, K15 with mechaniduct (conduit); cal protection (armor) Table 36.5.3: NFC13200 Table 52E

Parallel lines with single-core cables Factor 𝑓 𝑠 = 0.8 shall be applied in case when there is an odd number of parallel lines (𝑛𝑙𝑛𝑢𝑚 >= 3) with single-core cables in three-phase systems (i.e. 3x3x1). Otherwise the value of fs is 1. Parallel lines with multi-core cables Factor 𝑓 𝑠 = 0.8 shall be applied in case when there are more lines in parallel (𝑛𝑙𝑛𝑢𝑚 > 1).

848

DIgSILENT PowerFactory 15, User Manual

Chapter 37

Motor Starting 37.1

Introduction

The chapter presents PowerFactory tools for performing motor starting simulations using the Motor Starting command (ComMot). A Motor Starting analysis typically includes an assessment of the following: • Voltage sag. • Ability of motor to be started against the load torque. • Time required to reach nominal speed. • Supply grid loading. • Starting methodology (Direct Online, Star-Delta, Variable Rotor Resistance, Reactor, Auto Transformer). The Motor Starting command makes use of the PowerFactory stability module by providing a preconfigured shortcut for easy-to-use motor starting analysis. Pre-selected and pre-configured plots (VIs) are automatically created and scaled with full flexibility for user-configuration. In PowerFactory , there are two “Simulation Types" that may be used to perform a motor starting simulation: 1. Dynamic Simulation, which will execute a time-domain motor starting simulation. 2. Static Simulation, which will execute a load flow calculation when the motors are disconnected from the system. Then, it will execute a short-circuit calculation, using the complete method, simultaneously with the occurrence of the motors being connected to the network. Finally, a load flow calculation will be executed after the motors have been connected to the system.

37.2

How to define a motor

To define the starting method of a motor, a Type must first be selected. This sub-section describes how to define a motor and (optionally) define a motor driven machine (mdm).

37.2.1

How to define a motor Type and starting methodology

A comprehensive library of low-voltage, medium-voltage, and high-voltage motor Types are available in the PowerFactory Global Library. Typical motors supported are: single- and double-cage asynchronous DIgSILENT PowerFactory 15, User Manual

849

CHAPTER 37. MOTOR STARTING machines and squirrel motors. To define a motor Type and starting methodology for a dynamic simulation: 1. On the asynchronous machine Basic Data page, press select ( or define a new asynchronous machine Type. Press OK twice.

) and then choose an existing

2. From the Data Manager or single line graphic, double-click the asynchronous machine to open the element dialogue. 3. Depending on whether a dynamic or static motor starting simulation is to be executed: • For a dynamic starting simulation, navigate to the RMS-Simulation page, Advanced tab. • For a static starting simulation, navigate to the Complete Short-Circuit page. 4. Check Use Motor Starting Method. 5. Use radio buttons to select a starting method (see below). Directly Online For the direct online starting method, select Directly Online. Star-Delta For star-delta starting: 1. Select Star-Delta. 2. For a dynamic motor starting simulation, on the RMS-Simulation page, Advanced tab: • Select Triggered by... either Time or Speed. • Enter a simulation time for the motor to switch from the star winding to the delta winding Switch to ’D’ after, or a speed for the motor to switch from the star winding to the delta winding Switch to ’D’ at Speed >=. Variable Rotor Resistance For variable rotor resistance starting: 1. Select Variable Rotor Resistance. 2. For a static motor starting simulation, on the Complete Short-Circuit page: • Enter the Additional Rotor Resistance. 3. For a dynamic motor starting simulation, on the RMS-Simulation page, Advanced tab: • Select Triggered by... either Time or Speed. • In the Variable Rotor Resistance table, enter additional rotor resistance, and the time (or speed) at which the rotor resistance should be added. • For additional entries, right-click and Append or Insert rows as required. Note that a minimum of two-points must be entered. Reactor For reactor starting: 1. Select Reactor. 2. For a static motor starting simulation, on the Complete Short-Circuit page: • Enter the Rated Apparent Power and Reactance. 850

DIgSILENT PowerFactory 15, User Manual

37.2. HOW TO DEFINE A MOTOR 3. For a dynamic motor starting simulation, on the RMS-Simulation page, Advanced tab: • Select Triggered by... either Time or Speed. • Enter the Rated Apparent Power, Reactance. • Enter the time at which the reactor should be removed Bypass after, or speed at which the reactor should be removed Bypass at Speed >=. Auto Transformer For auto transformer starting: 1. Select Auto Transformer. 2. For a static motor starting simulation, on the Complete Short-Circuit page: • Enter the Rated Apparent Power, Reactance, and Tap. 3. For a dynamic motor starting simulation, on the RMS-Simulation page, Advanced tab: • Select Triggered by... either Time or Speed. • Enter the Rated Apparent Power, Reactance, and Tap. • Enter the time at which the star contactor should be released Release Star Contactor after and the time at which the auto-transformer should be bypassed Bypass after, or the speed at which the star contactor should be released Release Star Contactor at Speed >= and the speed at which the auto-transformer should be bypassed Bypass at Speed >=.

37.2.2

How to define a motor driven machine

Selection of a motor driven machine model provides enhanced flexibility to define the torque-speed characteristic of the motor. A motor driven machine can be user-defined, or selected from a range of Compressors, Fans, and Pumps available in the PowerFactory Global Library. Refer to the asynchronous machine Technical Reference Asynchronous Machine and motor driven machine Technical Reference for further details Motor Driven Machine. To define a motor driven machine, in a Data Manager or on the Single Line Graphic, right-click on the asynchronous machine and: • For a new motor driven machine: 1. Select Define... → New Motor Driven (mdm) machine. 2. Select a motor driven machine element (Type 1, Type 3, or Type 5). 3. Enter the torque-speed characteristic. • For a motor driven machine from the library: 1. Select Define... → Motor Driven (mdm) machine from library. 2. Select an existing motor driven machine from the project library, or global library Database → Library → Motor Driven Machine. Note: Motor driven machines may also be defined for Synchronous motors by selecting the “Composite Type Sym frame" (or creating a user-defined frame). Refer to the mdm Technical Reference for further details: Motor Driven Machine.

DIgSILENT PowerFactory 15, User Manual

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CHAPTER 37. MOTOR STARTING

37.3

How to run a Motor Starting simulation

To run a motor starting simulation: 1. Select the motor or group of motors for the motor starting simulation. 2. Right-click a selected motor and select Calculate → Motor Starting. 3. Enter the command options (see following subsections for a description of the command options).

37.3.1

Basic Options Page

37.3.1.1

Motor(s)

The motors selected for the Motor Starting command.

37.3.1.2

Simulation Type

Select either: • Dynamic Simulation to initiate a dynamic motor starting simulation. • Static Simulation to initiate a static motor starting simulation. Note: Load Flow, Initial Conditions, Run Simulation, Simulation Events, Short-Circuit and Results Definitions objects in the active study case will be overwritten by the Motor Starting command.

37.3.1.3

Simulation Method

Either: • If User defined simulation settings is not checked: 1. Select to run either a Balanced or Unbalanced Motor Starting simulation. 2. Enter the Simulation Time in seconds. • If User defined simulation settings is checked: 1. Define the variables to be monitored. 2. Modify Load Flow Calculation command (ComLdf ) settings as required. 3. Modify Initial Conditions command (ComInc) settings as required. Note that motor starting events are automatically created, and that previously defined events are not deleted. Similarly, user-defined variable sets are merged with the Motor Starting command default variables. 4. Modify Simulation command (ComSim) settings as required.

37.3.1.4

Monitoring

Click Select ( 852

) and select the Additional Terminals to be monitored for the Motor Starting simulation. DIgSILENT PowerFactory 15, User Manual

37.3. HOW TO RUN A MOTOR STARTING SIMULATION 37.3.1.5

Check Thermal Limits of Cables and Transformers

Optionally select to Check Thermal Limits of Cables and Transformers. When this option is selected, the feeding cables and transformers of every motor will automatically be gathered, and its thermal limit will be checked. The calculation of the thermal limits is performed depending on the type of simulation selected. • Dynamic Simulation Given the rated thermal overcurrent limit of the cable at 1 second (𝐼𝑡ℎ𝑟1𝑠 ), the thermal overcurrent limit of the line at the starting time of the motor (𝐼𝑡ℎ𝑟𝑇 𝑠 ) is calculated according to equation 37.1: √︂ 𝐼𝑡ℎ𝑟𝑇 𝑠 =

𝐼𝑡ℎ𝑟1𝑠 𝑇𝑠𝑡𝑎𝑟𝑡

(37.1)

Where: 𝑇𝑠𝑡𝑎𝑟𝑡 = is the time calculated during the Motor Starting simulation. The calculated thermal energy (𝐼2𝑡 ) during the motor starting is defined as:

∫︁ 𝐼2𝑡 =

𝑇𝑠𝑡𝑎𝑟𝑡

𝐼 2 𝑑𝑡 ≈

𝑇∑︁ 𝑠𝑡𝑎𝑟𝑡

0

𝐼 2 ∆𝑡

(37.2)

0

Where: ∆𝑡 = is the integration step size of the simulation. The calculated thermal current (𝐼𝑡ℎ𝑟𝑐𝑎𝑙𝑐 ) is then calculated as follows: √︂ 𝐼𝑡ℎ𝑟𝑐𝑎𝑙𝑐 =

𝐼2𝑡 𝑇𝑠𝑡𝑎𝑟𝑡

(37.3)

Finally, the thermal loading is calculated as the relation between rated thermal current and calculated thermal current at starting time:

𝑇 ℎ𝑒𝑟𝑚𝑎𝑙𝐿𝑜𝑎𝑑𝑖𝑛𝑔 =

𝐼𝑡ℎ𝑟𝑐𝑎𝑙𝑐 𝐼𝑡ℎ𝑟𝑇 𝑠

(37.4)

• Static Simulation Given the rated thermal overcurrent limit of the cable at 1 second (𝐼𝑡ℎ𝑟1𝑠 ), the thermal overcurrent limit of the line at the starting time of the motor (𝐼𝑡ℎ𝑟𝑇 𝑠 ) is calculated according to equation 37.5 : √︂ 𝐼𝑡ℎ𝑟𝑇 𝑠 =

𝐼𝑡ℎ𝑟1𝑠 𝑇𝑠𝑡𝑎𝑟𝑡

(37.5)

The starting time is the variable 𝑡𝑠𝑡𝑎𝑟𝑡 specified in the “Protection" page of the Asynchronous and the Synchronous Machine dialogues. The calculated thermal current is the positive-sequence current calculated at the motor starting

𝐼𝑡ℎ𝑟𝑐𝑎𝑙𝑐 = 𝐼𝑠𝑡𝑎𝑟𝑡 DIgSILENT PowerFactory 15, User Manual

(37.6) 853

CHAPTER 37. MOTOR STARTING Finally, the thermal loading is calculated as the relation between rated thermal current and calculated thermal current at starting time:

𝑇 ℎ𝑒𝑟𝑚𝑎𝑙𝐿𝑜𝑎𝑑𝑖𝑛𝑔 =

37.3.2

Output Page

37.3.2.1

Dynamic Simulation

𝐼𝑡ℎ𝑟𝑐𝑎𝑙𝑐 𝐼𝑡ℎ𝑟𝑇 𝑠

(37.7)

Report Check Report to report results to the output window. By default, report results include voltage before starting, minimum voltage during starting, voltage after starting, starting current and power factor, successful start, and starting time. The user can optionally modify report Settings. Starting Tolerance for Simplified Models Define the Max. Speed Tolerance, the maximum deviation from nominal speed at which the motor is considered to be successfully started. This applies only to simplified (i.e. synchronous) motors.

37.3.2.2

Static Simulation

Report Optionally modify report Settings and Results. Figure 37.3.1 shows an example of a Static Simulation Report with the option “Check Thermal Limits of Cables and Transformers" selected.

Figure 37.3.1: Report Example

Starting Tolerance for Simplified Models Define the Max. Voltage Drop at which the motor is considered to be successfully started. This applies only to simplified models. Simplified models are: 854

DIgSILENT PowerFactory 15, User Manual

37.3. HOW TO RUN A MOTOR STARTING SIMULATION • All synchronous motors. • Asynchronous motors with type Asynchronous Machine Type (TypAsmo), and without the Type option Consider Transient Parameter (i_trans) checked. • Asynchronous motors with any Type other than Asynchronous Machine Type (TypAsmo). Detailed models are: Asynchronous motors with type Asynchronous Machine Type (TypAsmo), and which have the option Consider Transient Parameter checked on the VDE/IEC Short-Circuit page or Complete Short-Circuit page of the Type dialog. This provides a more precise result for the motor starting time. Display results for Select to display results on the Single Line Graphic: • After motor start up. • During motor start up. • Before motor start up.

37.3.3

Motor Starting simulation results

37.3.3.1

Dynamic simulation results

Following a motor starting simulation, PowerFactory will automatically create a plot (VI) for each motor showing the active power (m:Psum:bus1), reactive power (m:Qsum:bus1), current (m:I1:bus1), speed (s:speed), mechanical and electrical torques (c:xmt and c:xmem) and voltage of the motor terminal (m:u1). A second plot is created showing the voltage of monitored Terminals. Flexible data results variables available following a dynamic Motor Starting simulation are found on the motor data Motor Starting Calculation page. The Motor Starting calculation variables are as follows: • Terminal voltage before Starting, Magnitude (c:uprestart). • Motor voltage during Starting, Magnitude (c:ustart). • Motor voltage after Starting, Magnitude (c:upoststart). • Starting current, Magnitude in kA (c:Istart). • Starting current, Magnitude in p.u. (c:istart). • Starting Power Factor (c:cosphistart). • Successfully Started (c:started). • Approx. Starting Time (c:Tstart). The criterion of a successful start is as follows: • Synchronous motors: Successful start if 𝐴𝑐𝑡𝑢𝑎𝑙𝑠𝑝𝑒𝑒𝑑 >= 𝑆𝑦𝑛𝑐ℎ𝑟𝑜𝑛𝑜𝑢𝑠𝑠𝑝𝑒𝑒𝑑 −𝑇 𝑜𝑙𝑒𝑟𝑎𝑛𝑐𝑒, where 𝐴𝑐𝑡𝑢𝑎𝑙𝑠𝑝𝑒𝑒𝑑 is the value of variable “s:speed", and 𝑇 𝑜𝑙𝑒𝑟𝑎𝑛𝑐𝑒 is the value specified in the input field Max. Speed Tolerance (tolspeed). • Asynchronous motors: Successful start if 𝐴𝑐𝑡𝑢𝑎𝑙𝑠𝑝𝑒𝑒𝑑 >= 𝑁 𝑜𝑚𝑖𝑛𝑎𝑙𝑠𝑝𝑒𝑒𝑑 −𝑆𝑙𝑖𝑝, where 𝐴𝑐𝑡𝑢𝑎𝑙𝑆𝑝𝑒𝑒𝑑 is the value of variable “s:speed", and 𝑆𝑙𝑖𝑝 is the value of variable “t:aslkp" of the asynchronous motor. DIgSILENT PowerFactory 15, User Manual

855

CHAPTER 37. MOTOR STARTING 37.3.3.2

Static simulation results

Following a motor starting simulation, new calculation variables are available for asynchronous (ElmAsm) and synchronous (ElmSym) motors. For the Static Simulation, these variables are found on the Motor Starting Calculation page. Results variables are described in the preceding sub-section. The criterion of a successful start is as follows: • Simplified models: Successful start if Voltage During Starting >= Voltage Before Starting *(1 - Voltage Tolerance), where Voltage Before Starting is the voltage value at the terminal before the motor is connected to the system, Voltage During Starting is the transient positive-sequence voltage value at the terminal during the motor start, and Voltage Tolerance is the value specified in the input field Max. Voltage Drop (tolvolt). • Detailed models: The electrical and mechanical torque are calculated for the minimum voltage value during the motor start up. A detailed model is considered to be successfully started up if the mechanical torque is always smaller than the electrical torque from zero speed up the peak of the electrical torque.

37.3.4

Motor Starting Example

Consider the following dynamic motor starting example for a single 6.6kV asynchronous motor shown in Figure 37.3.2.

Figure 37.3.2: Motor Starting example Single Line Graphic

The Variable Rotor Resistance starting method has been selected, with three values of time-dependent resistance, as shown in Figure 37.3.3. 856

DIgSILENT PowerFactory 15, User Manual

37.3. HOW TO RUN A MOTOR STARTING SIMULATION

Figure 37.3.3: Motor starting methodology options

A dynamic, balanced Motor Starting simulation is executed and run to 10 seconds, with “Source Bus" selected as an Additional Terminal to be monitored, as shown in Figure 37.3.4.

Figure 37.3.4: Motor starting Basic Options

Following execution of the command, PowerFactory automatically produces plots showing motor quantities of interest (as described in section 37.3.3.1) and monitored voltage results as shown in Figure 37.3.5 and Figure 37.3.6.

DIgSILENT PowerFactory 15, User Manual

857

CHAPTER 37. MOTOR STARTING

Figure 37.3.5: Motor starting example motor results

Figure 37.3.6: Motor starting example voltage results

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DIgSILENT PowerFactory 15, User Manual

Chapter 38

Arc-Flash Hazard Analysis 38.1

Introduction

This chapter presents the tools available in PowerFactory to perform arc-flash hazard analysis, including technical background, a description of the Arc-Flash Hazard Analysis command dialogues, and an example calculation. The Arc-Flash Hazard Analysis command (ComArcflash) can be accessed on the Main Toolbar under the Protection group by selecting the Arc-Flash Hazard Analysis icon . Note: DIgSILENT accepts no responsibility for the use of the Arc-Flash Hazard Analysis command, or for the consequences of any actions taken on the basis of the results. Use the Arc-Flash Hazard Analysis command at your own risk.

Note: By default, results are entered and displayed in SI units. To change to British Imperial units, on the Main Menu, select Edit → Project Data→ Project, select the pointer to Project Settings, and on the Input page, select the Units as “English-Transmission" or “English-Industry".

38.2

Arc-Flash Hazard Analysis Background

38.2.1

General

Arc-Flash Hazard Analysis calculations are performed to determine “...the arc-flash hazard distance and the incident energy to which employees could be exposed during their work on or near electrical equipment" [IEEE1584-2002][17]. One outcome of an Arc-Flash Hazard Analysis is to determine employee Personal Protective Equipment (PPE) requirements. Arc-Flash calculations can be conducted in PowerFactory in accordance with IEEE-1584 2002[17] and NFPA 70E 2008 [19] standards. The Arc-Flash Hazard Analysis command builds on the existing shortcircuit calculation capabilities of PowerFactory , and requires the following additional data, depending on the method used: • IEEE-1584: Conductor Gap, Distance Factor, Working Distance, and Enclosure type. • NFPA 70E: Working Distance. When an Arc-Flash hazard analysis is conducted using the IEEE-1584 method, PowerFactory calculates the arcing current based on the equations presented in the standard. Internally, PowerFactory DIgSILENT PowerFactory 15, User Manual

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CHAPTER 38. ARC-FLASH HAZARD ANALYSIS calculates the arc resistance required to limit the fault current to the calculated value. When the NFPA method is selected, the bolted fault current is used for the calculation. For either method, when the user selects to use relay tripping times, a second calculation is performed at a reduced fault current (as specified by the user) and the associated (generally longer) clearing time. PowerFactory compares the results of these two cases and reports on the worst case result.

38.2.2

Data Inputs

The IEEE-1584 Standard provides guidance on the selection of Conductor Gap and Distance Factor. Figure 38.2.1 shows the recommended values from the standard.

Figure 38.2.1: Factors for Equipment and Voltage Classes [IEEE1584-2002][17]

Figure 38.2.2 shows the Terminal Element dialogue where parameters required for the Arc-Flash Hazard Analysis Calculation are entered. If Accessible Location is selected, the user may enter the required input parameters for Arc-Flash calculations. If the Terminal resides within a Substation, Equipment Data can be set to either Local Values or From Substation. When From Substation is selected, a pointer to the relevant substation is shown in the dialogue.

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38.3. ARC-FLASH HAZARD ANALYSIS CALCULATION OPTIONS

Figure 38.2.2: Arc-Flash Data Required for Terminal Objects

Additional data required for Fault Clearing Times is discussed later in the chapter.

38.3

Arc-Flash Hazard Analysis Calculation Options

This section describes the Arc-Flash Hazard Analysis calculation options.

38.3.1

Arc-Flash Hazard Analysis Basic Options Page

Calculation Method Select either: • according to IEEE-1584[17], or • according to NFPA 70E[19]. Fault Location Select either: • At User Selection, and select a single location, or a pre-defined Set of locations. • All Accessible Locations, i.e. all Terminals where Accessible Location is selected on the Protection page of the Element dialogue. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 38. ARC-FLASH HAZARD ANALYSIS Fault Clearing Times Select either: • Use Fixed Times. In which case, detailed protection models are not required by the calculation, and the following should be defined: – If Get Time from Global is selected, then define the Protection Tripping Time and Breaker Opening Time. – If Get Time from Local is selected, then define the Maximum Time, the maximum fault clearing time used by the Arc-Flash command. The clearing times used by the arc-flash command are taken from the Protection page of (ElmCoup) and (ElmSwitch) Elements, with Switch Type set to “Circuit Breaker" on the Basic Data page. • Use Relay Tripping. In which case, the tripping time is based upon the relay characteristic entered in the protection model (provided that on the relay(s) Description tab, the Status is set to “Approved"). The Arc-Flash Hazard Analysis command performs Incident Energy calculations using this tripping time, and the tripping time based on a reduced fault current, as specified on the Advanced Options page (parameter Arcing Current Variation). If Use Relay Tripping is selected, then select to: – Get Time from either: * Initial, in which case the arc-flash command determines the fault clearing time based on the longest fault clearing time of any element connected to the faulted terminal. For example, if two parallel lines are connected to a faulted terminal, and the first line has a fault clearing time of 1 s, and the second line has a fault clearing time of 2 s (where both clearing times are based on the Initial fault current) the arc-flash command will take 2 s as the fault clearing time. * Iteration, in which case the arc-flash command determines the fault clearing time from a Short-Circuit Trace calculation. For example, if two parallel lines are connected to a faulted terminal, and the first line has a fault clearing time of 1 s. Then, after the first line is cleared, the second line sees a higher fault current, and subsequently clears the fault at 1.5 s. The arc-flash command takes 1.5 s as the fault clearing time. – Define the Maximum Time, the maximum fault clearing time used by the Arc-Flash command. Short-Circuit Calculation Pointer to the Short-Circuit Calculation command. Show Output If selected, the pointer to the Output of Results can be modified. See Section 38.4 for details. Note: When there are multiple sources of fault current to a faulted Terminal with different fault clearing times, PowerFactory takes the maximum clearance time of the connecting branch for all branches.

38.3.2

Arc-Flash Hazard Analysis Advanced Options Page

Arc-Flash Calculation Options

• Define the Arcing Current Variation, that is, the percentage the bolted-fault current is reduced by for the second calculation (see 38.3.1). • Define the Energy at Flash-Protection Boundary. PPE-Ratings Select either: 862

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38.4. ARC-FLASH HAZARD ANALYSIS RESULTS • Acc. to NFPA 70E[19], in which case default values from the standard are used. • User-Defined, in which case user-defined Category values can be entered in the PPE-Categories table after inserting or appending rows. Note that values should be entered in ascending order.

38.4

Arc-Flash Hazard Analysis Results

38.4.1

Viewing Results in the Single Line Graphic

Results Boxes Terminals can be coloured according to calculated PPE category, and the calculated flash protection boundary. To set the diagram colouring mode, select the Diagram Colouring icon, and then under 3. Other, select Results, and then the desired colouring mode. Diagram Colouring To show the default set of Arc-Flash results on the Single Line Graphic (Boundary Distance, PPE Category, and Incident Energy), right-click the Terminal results box and select Format for Short Circuit Nodes → Arc-Flash. Arcing Current and Fault Clearing Time results can also be displayed.

38.4.2

Arc-Flash Reports Dialogue

The Arc-Flash Reports (ComArcreport) dialogue can be used to configure the output of tabular results from an Arc-Flash calculation. Additionally, “Database" and “Template" files can be selected in order to facilitate the preparation of Arc-Flash Hazard warning labels. The following inputs are available in the Arc-Flash Reports dialogue. Create Label Database If selected, Database and Template filenames should be specified. By default, a default Template is selected by PowerFactory. Note that the Database Excel file should not be open when Create Label Database is checked and the command is executed. Available Variables and Selected Variables Variables to be included in the Tabular report can be selected or deselected (in which case they will be on the Available Variables pane. Create Tabular Report Select whether to Create Tabular Report, and define the Min. PPE-Category and Min. Incident Energy to be included in the Tabular report. Once the tabular report is created, Min. PPE-Category and Min. Incident Energy can be modified if required. After being executed, the Tabular Report can be exported as HTML format or exported directly to Excel, by using the Select icon ( ). Note: If the incident energy exceeds the incident energy at the maximum PPE category, the result is “N/A".

38.4.3

Arc-Flash Labels

The “Create Label Database" option, handled by a DPL script, triggers an export of the selected variables to a Microsoft Excel file at the selected location. After the export of label data, a copy of the given label template will be stored at the same location as the Excel file and renamed accordingly. (i.e. if the Excel file is called “ArcFlash.xls", the copy of the template will be called “ArcFlash.doc"). If a template DIgSILENT PowerFactory 15, User Manual

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CHAPTER 38. ARC-FLASH HAZARD ANALYSIS file with this name already exists, the user will be prompted if it should be overwritten. The template copy will be opened after the export is completed. The user can use the mail merge feature of Microsoft Word to create a series of labels based on the template and the Excel data file. To link the template copy with the database: • Go to the “Mailings" tab, in the “Start Mail Merge" group, and click on “Select Recipients". • From the drop down menu, select “Use Existing List...", and then select the label database Excel file. • Still on the “Mailings" tab, in the “Preview Results" group, click on “Preview Results" to view the label(s). • To store or print the finished labels, still on the “Mailings" tab, in the “Finish" group, click on “Finish & Merge". For more information about the mail merge and how to create a template, refer to the MS-Word help. Also note that data can be copied from the Flexible Data tab of the Data Manager for post-processing and creation of labels.

38.5

Example Arc-Flash Hazard Analysis Calculation

Consider the example network shown in Figure 38.5.1, where there are two parallel lines connected to a Terminal “Terminal". For this example, the two lines have different protection characteristics, as shown in Figure 38.5.2.

Figure 38.5.1: Example Network Single Line Graphic

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38.5. EXAMPLE ARC-FLASH HAZARD ANALYSIS CALCULATION

Figure 38.5.2: Example Network Single Line Graphic

Arc-Flash calculations are conducted using each method: • With Use Fixed Times and Get Time from Global selected, and with a total fault clearing time of 0.12 s, the key results are as follows: – Incident Energy: 58 J∖cm2 . – Boundary Distance: 583 mm. – PPE Category: 3. • With Use Fixed Times and Get Time from Local selected, and with a total fault clearing time of 0.10 s, the key results are as follows: – Incident Energy: 49 J∖cm2 . – Boundary Distance: 624 mm. – PPE Category: 3. • With Use Relay Tripping and Get Time from Initial selected, the key results are as follows: – Incident Energy: 37 J∖cm2 . – Boundary Distance: 544 mm. – PPE Category: 3. • With Use Relay Tripping and Get Time from Iteration selected, the key results are as follows: – Incident Energy: 24 J∖cm2 . – Boundary Distance: 441 mm. – PPE Category: 2. Of particular interest is the difference between the results for the case where Get Time from Initial is selected, versus Get Time from Iteration. The former case gives conservative results (in this example), whilst in the latter case, the fault clearing time is faster due to recalculation of the fault current (as discussed in Section 38.3.1), and thus the calculated PPE requirement is lower. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 38. ARC-FLASH HAZARD ANALYSIS A label is produced for “Terminal" (as described in 38.4), for the method where Relay Tripping, and Get Time from Initial is selected. The resultant label is shown in Figure 38.5.3.

Figure 38.5.3: Example Arc-Flash Warning Label

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Chapter 39

Protection 39.1

Introduction

PowerFactory enables the user to define a protection scheme by integrating protective devices into the system defined by a project’s network model. The software can be used to assist with the coordination of protective devices and for generating graphical representations of protection system characteristics. Models of both generic and manufacturer specific relays are available for use with the software. The following plot types are supported by PowerFactory : • Current vs time plots (Time-overcurrent plots. Refer Section 39.4) • Distance vs time plots (Time-distance diagrams. Refer Section 39.7) • Impedance plots (R-X diagrams. Refer Section 39.6) Furthermore, PowerFactory allows for the creation of a protection single line diagram (refer Section 39.2.3) for visualisation of the location of the protection devices within the network. PowerFactory also includes a distance protection coordination assistant (refer Section 39.8) to automatically configure appropriate settings for distance protection schemes. This chapter will describe how setup a network model for protection analysis, how to use PowerFactory ’s protection analysis functions and plots and how to output results from the analysis in convenient settings reports. The following section presents a general introductory overview of protection modelling within PowerFactory. Although it is not a pre-requisite for the user to have an understanding of the internal modelling approach in order to use PowerFactory ’s basic protection functions, an understanding will help the user to appreciate the structure of the dialogues encountered when setting up a protection scheme. Users who wish to move straight into the creation of a protection scheme may wish to skip this section.

39.1.1

The modelling structure

Protection devices form a group of highly complex and non-uniform power system devices. Any program tasked with modelling these devices faces a difficult dilemma. On the one hand, the relay models should be as flexible and versatile as possible to ensure that all types of protection relays can be modelled with all of their features. On the other hand, the relay models should be as simple as possible to reduce the amount of work and knowledge needed to define power system protection devices. This dilemma is solved in PowerFactory by modelling protection devices using a tiered approach consisting of three different levels. These levels are: DIgSILENT PowerFactory 15, User Manual

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CHAPTER 39. PROTECTION • the relay frame • the relay type • the relay element Each of these levels fulfill a different role in the modelling of a protection device. Figure 39.1.1 shows the relation of these three levels graphically.

Figure 39.1.1: Modelling structure for protection devices

39.1.2

The relay frame

The relay frame specifies the general relay functionality using a diagram where functional blocks known as slots are connected by signals. Slots for timers, measurement and logic elements can be defined. It defines how many stages the relay consists of and how these stages interact. However, the relay frame contains no mathematical or logical functions, rather these are specified by the internal types referenced by the slots. Each slot is defined by the number of input and output signals. The signal lines define how the slots are interconnected. Relay frames are similar to the frames of composite models and are created in the same way. See Chapter 26:Stability and EMT Simulations, Section 26.9.2 (The Composite Frame) for more information. Figure 39.1.2 shows an example of a relay frame for a two stage overcurrent relay. The illustrated relay frame contains a measurement slot, two instantaneous overcurrent slots (each representing one stage of the overcurrent relay) and a logic slot. Connections between slots are illustrated by lines with arrowheads.

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Figure 39.1.2: Typical relay frame

39.1.3

The relay type

The relay type associated with a specific relay frame, is defined by selecting a block definition for each slot of the frame. Assigning a block definition to a slot converts the slot to a block, representing a mathematical function which describes the behaviour of a physical element. For example, the type of filter used for processing the input signals, or the type of relay operating characteristic. Because many relays support more than one type of characteristic, a set of characteristics or functions can be defined. In addition, the relay type specifies the ranges for the various relay settings, including whether the parameters are set continuously or in discrete steps. The relay type defines the library information for a specific manufacturer’s relay, which does not yet have any settings applied to it. The complete information described in the data sheet and manual is contained in the relay type. An advantage of this split concept is the possibility of re-using a relay frame for more than one relay type. Figure 39.1.3 shows the type dialogue associated with an instantaneous overcurrent slot as an example. Parameters that normally cannot be influenced by the user, like the Pick-up Time, are defined in the type as well.

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Figure 39.1.3: Type dialogue of an instantaneous overcurrent block

39.1.4

The relay element

The relay element models the actual relay in a power system. It refers to a relay type in the library, which provides the complete relay structure including the setting ranges for all parameters. The actual settings of the relay, for example, the reach or the pick-up settings, are part of the relay element settings, considering the range limitations defined by the relay type. CT and VT models are the input link between a relay element and the electrical network. For the relay output, a tripping signal is sent directly from the relay element to a circuit breaker in the network. To simulate busbar protection, differential protection, or tele-protection schemes, a relay element can operate more than one circuit breaker. Figure 39.1.4 shows the block element dialogue belonging to the type dialogue in Figure 39.1.3.

Figure 39.1.4: Element dialogue of an instantaneous overcurrent relay

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39.2. HOW TO DEFINE A PROTECTION SCHEME IN POWERFACTORY

39.2

How to define a protection scheme in PowerFactory

This section describes the procedures necessary for defining a protection scheme within PowerFactory. It begins with a brief overview of the procedure followed by detailed instructions for how to define protection devices within the PowerFactory model.

39.2.1

Overview

Before construction of a protection scheme can be completed, it is necessary to construct a model of the network to be protected. See Section 9.2 for instructions of how to build a network model in PowerFactory. A protection scheme is defined by adding relays (or fuses) and their associated instrument transformers at appropriate places within the network model. After adding the device models, the settings can be adjusted through manual entry, by using the automated coordination tools and plots, or by importing the relay settings directly from StationWare (refer to Section 20.10). The PowerFactory protection modelling features have been designed to support the use of “generic" relays or “detailed" models of relays based on manufacturer specific devices. For “generic" relays, PowerFactory includes a global library containing some predefined generic relays, fuses and instrument transformers that can be used to design schemes without requiring specific details of a particular relay manufacturer’s range of products. This can be useful during the early stages of the definition of a protection scheme. By creating a model with generic protection devices, the user can confirm the general functionality of a scheme before relay procurement decisions are finalised. For detailed definition and analysis of protection schemes, it is recommended to use detailed relay manufacturer specific models. DIgSILENT offers many such models from the user download area on the DIgSILENT website. Of course, with thousands of different relay models in existence and more being created, in some instances a model will not exist. In such cases, advanced users can define their own relay models or contact DIgSILENT support for further advice. The following section will explain how to add predefined protective devices (generic or manufacturer specific) to a network model.

39.2.2

Adding protective devices to the network model

Protection devices in PowerFactory must be placed within cubicles (refer to Section 4.7.3 for more information on cubicles). There are several methods to add or edit the protection devices in a cubicle: 1. Through the protection single line diagram. Refer to Section 39.2.3. 2. Right-clicking a switch-symbol (New devices): (a) Right-click a switch symbol in the single line graphic as illustrated in Figure 39.2.1. This will show a context sensitive menu. (b) Choose New Devices → Relay Model. . . /Fuse. . . /Current Transformer. . . /Voltage Transformer. . . . A dialogue for the chosen device will appear. 3. Right-clicking a switch symbol (Edit devices): (a) Right-click a switch symbol in the single line graphic as illustrated in Figure 39.2.1. This will show a context sensitive menu.

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CHAPTER 39. PROTECTION (b) Choose the option Edit Devices. A dialogue showing the devices currently within the cubicle will appear. (c) Click the

icon. A dialogue will appear.

(d) Choose the desired device type. (e) Click OK and the dialogue for the new device will appear. 4. Through the protected device (line, transformer, load etc): (a) Double-click the target element to protect. A dialogue showing the device basic data should appear. (b) Click the button next to the end of element where you want to place the protective device. For a line element this will say “Terminal i/j" and for a transformer this will say “HV/LV-side". A menu will appear. See Figure 39.2.2 for example. (c) Click Edit Devices. (d) Click the

icon. A dialogue will appear.

(e) Choose the desired device type. (f) Click OK and the dialogue for the new device will appear. 5. Through the substation: (a) Open a detailed graphic of the substation. Refer Section 9.2.6 for more information on substation objects. (b) Right-click the specific part of the substation where you would like to add the relay. A context sensitive menu will appear. See Figure 39.2.3 for an example substation showing possible locations where protection devices can reside. (c) Choose New Devices or Edit Devices and following the remaining steps from 2b or 3c respectively. The areas which can be right clicked in a typical detailed substation graphic are ringed in Figure 39.2.2. After completing one of the methods above, the created device also must be configured. Usually this involves selecting a type and entering settings. Further information about configuring overcurrent protection device elements is explained in Section 39.3 and distance protection devices in Section 39.5. Note: When adding a protection device by right-clicking on a switch (Method 2), ensure the element connected to the switch is not already selected. Otherwise, you will create devices at both ends of the element. If you select the switch successfully, only half of the connected element will be marked when the context sensitive menu appears.

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39.2. HOW TO DEFINE A PROTECTION SCHEME IN POWERFACTORY

Figure 39.2.1: Adding a new relay to a single line diagram

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Figure 39.2.2: Editing line protection devices

Figure 39.2.3: Adding a new protective device to a detailed substation graphic

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39.2.3

Protection single line diagrams

DIgSILENT

PowerFactory supports adding protection devices directly to the network single line diagram. Existing protection devices located within cubicles can also be added to the diagram using the Draw Existing Net Elements tool (refer to Section 9.6). An example of a complete protection single line diagram is shown in Figure 39.2.4. In this diagram the protection relays are indicated with the “R" inside a rectangle, current transformers as a brown circle with the measured circuit underneath and voltage transformers as a brown circle with a semi-circle above and a line connecting to the measured bus. Black lines between the measurement transformers and the relays show the connection of the secondary side of the instrument to the relay.

Relay with CT connection

R

R

R

Relay with VT connection

R

Figure 39.2.4: An example protection single line diagram

39.2.3.1

How to add relays to the protection single line diagram

To add a relay to the protection single line diagram: 1. Open an existing network diagram. 2. Click the

button on the drawing toolbar.

3. Click the switch where the relay should be placed. 4. Optional: click and drag to reposition the relay to an alternative location. Note: The relay icon in the protection diagram can also be resized. Select the relay and then click and drag from the corner of the device.

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CHAPTER 39. PROTECTION 39.2.3.2

How to add current transformers to the protection single line diagram

To add a current transformer to the single line diagram: 1. Open an existing network diagram. 2. Click the

button on the drawing toolbar.

3. Click the switch where the CT should be placed. 4. Click the relay to connect the secondary side of the CT. Note: Before placing current transformers in the single line diagram it is recommended to place the relays that the secondary side of the device will connect to.

39.2.3.3

How to add voltage transformers to the protection single line diagram

To add a voltage transformer to the single line diagram: 1. Open an existing network diagram. 2. Click the

button on the drawing toolbar.

3. Click the bus where the primary side of the VT should connect. 4. Click the relay to connect the secondary side of the VT. Note: Before placing voltage transformers in the single line diagram it is recommended to place the relays that the secondary side of the device will connect to.

39.2.3.4

How to connect an instrument transformer to multiple relays

In some cases it might be desirable to connect a CT or VT to multiple relays. To do so follow these steps: 1. Open an existing network diagram 2. Click the

button on the drawing toolbar.

3. Click the CT or VT that requires another connection. 4. Optional: Click at multiple points within the single line diagram to create a more complicated connection path. 5. Click the target relay for the connection.

39.2.4

Locating protection devices within the network model

Protection devices can be added to the network model by placing them in the single line diagram directly as described in Section 39.2.3. However, in cases where the devices are not drawn directly in the single line diagram, there are several methods to highlight the location of the devices in the single line diagram. This section describes these methods. 876

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39.3. SETUP OF AN OVERCURRENT PROTECTION SCHEME 39.2.4.1

Colouring the single line diagram to show protection devices

The single line diagram can be coloured to indicate the location of protective devices. To do this: 1. Click the

button on the graphics toolbar. The diagram colouring dialogue will appear.

2. Check the box for 3. Other. 3. Select Secondary Equipment from the first drop down menu. 4. Select Relays, Current and Voltage transformers from the second drop down menu. 5. Click OK to update the diagram colouring. The cubicles containing protection devices will be coloured according to the legend settings.

39.2.4.2

Locating protective devices using the object filter

To locate protection devices using the built-in object filters follow these steps: 1. Click the

icon from the main toolbar. A list of available objects will appear.

2. Click for relays, for fuses, for current transformers or of calculation relevant objects will appear within a tabular list.

for voltage transformers. A list

3. Right-click the icon of one or more objects in the list. A context sensitive menu will appear. 4. Select Mark in Graphic. The cubicle/s containing the object/s will be highlighted in the single line diagram.

39.3

Setup of an overcurrent protection scheme

Section 39.2.2, explained the initial steps required to add a protective device to the network model. When a new device is created within a network model there are a number of parameters to define in the dialogue which appears. This section will describe the basic steps required to specify these parameters for overcurrent relays and fuses. The following section, 39.4 describes the use of the main tool for analysing overcurrent protection schemes, the time-overcurrent diagram.

39.3.1

Overcurrent relay model setup - basic data page

The basic data page in the relay model (ElmRelay ) dialogue is where the basic configuration of the relay is completed. Generally it is required to complete the following steps: • Select the relay type (generic or manufacturer specific). Refer to Section 39.3.1.1. • Select the instrumentation transformers. Refer to Section 39.3.1.2 • Enter the relay settings. Refer to Section 39.3.1.3.

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CHAPTER 39. PROTECTION 39.3.1.1

Selecting the relay type

To select a generic relay type from the relay basic data page: 1. Click the

icon. A menu will appear.

2. Choose Select Global Type. . . . A data page showing the global relay library will appear. 3. Navigate into the sub-folders under “Generic" and select the desired relay type. 4. Click OK to assign the relay type. Note the basic data page of the relay will now show many different slots which are based on the configuration of the relay type. See Figure 39.3.1 for an example of a basic overcurrent relay dialogue. To select a manufacturer specific relay type from the relay basic data page: 1. Download the desired relay device model from the user download area on the DIgSILENT website. 2. Import this relay model into your database. By default newly imported relays are imported into the database folder “Relay Library" within your user area. However, you might like to import the relay into your local project library as an alternative. 3. Click the

icon. A menu will appear.

4. Choose Select Project Type. . . . A data page showing the local type library will appear. 5. Locate the relay either within your local library, or within the “Relay Libary" in your user area. 6. Click OK to assign the relay type. Note the basic data page of the relay will now show many different slots. These are the functional protection blocks such as time-overcurrent, measurement, differential, impedance and so on that contain the relay settings. The number and type of slot within the relay is determined by the relay type that you select.

39.3.1.2

Selecting the relay instrument transformers

If there were some instrument transformers within the cubicle when the relay was created, then these will automatically be assigned to the appropriate slots within the relay. However, if it is desired to select an alternative instrument transformer then follow these steps: 1. Right-click the cell containing the instrument transformer. A menu will appear. 2. Choose Select Element/Type. . . . A data browser will appear showing the contents of the relay cubicle. 3. Select an alternative instrument transformer here, or navigate to another cubicle within your network model. 4. Click OK to choose the instrument transformer. If the cubicle where the relay was created does not contain any current transformers, then a Create CT will appear at the bottom of the dialogue. If the relay also has at least one VT slot, a Create VT button will also appear. By clicking on these buttons it is possible to create a VT or CT and have them automatically assigned to vacant slots within the relay. For instructions for configuring a CT refer to Section 39.3.3 and for configuring a VT refer to Section 39.3.4.

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39.3. SETUP OF AN OVERCURRENT PROTECTION SCHEME 39.3.1.3

Entering the relay settings

To edit relay settings: 1. Locate the desired slot that you would like to modify. You may need to scroll down to locate some slots in complicated relay models. 2. Double-click the target slot. The dialogue for the clicked element will appear. 3. Enter or modify the settings.

39.3.1.4

Other fields on the relay basic data page

There are several other fields on the relay basic data page: Application This field is for documentation and searching purposes only. Device Number This field is also for documentation and searching purposes only. Location By default these fields give information about the relay location within the network model based upon the cubicle that it is stored within. However, it is possible to select an alternative Reference cubicle. If an alternative reference cubicle is selected, then the relay will control the switch within this cubicle. Furthermore, changing the reference location will also affect the automatic assignment of instrument transformers and the cubicle where any instrument transformers created using the Create VT or Create CT buttons will be placed.

39.3.2

Overcurrent relay model setup - max/min fault currents tab

This tab can be used to enter the minimum and/or maximum fault currents occurring at the location of the relay. These values are used to scale the Time-Overcurrent plot according to the given fault currents. They can be entered either manually or calculated with the Short-Circuit-Command. Note: The currents entered on this page will not affect the relay model. They are for plotting purposes only.

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Figure 39.3.1: Relay model dialogue with selected type

39.3.3

Configuring the current transformer

A new current transformer (CT) can be created as described in section 39.2.2 (Adding protective devices to the network model). Alternatively a CT can be created by using the Create CT button in the relay model dialogue. The dialogue as depicted in Figure 39.3.2 will then appear.

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39.3. SETUP OF AN OVERCURRENT PROTECTION SCHEME

Figure 39.3.2: The Current Transformer dialogue

The process of configuring the CT is: 1. Select/Create the CT type. Refer to Section 39.3.3.1 for information about the CT type. 2. Optional: If you would like to setup the CT to measure a location other than its parent cubicle or as an auxiliary CT, you can choose this through the Cubicle. Refer to Section 39.3.3.2 for further instructions. 3. Optional: Alter the Orientation. Positive current is measured when the flow is away from the node towards the branch and the Orientation is set to Branch. 4. Set the Primary ratio through the drop down menu next to Tap. The available ratios are determined by the selected CT type. If no type is selected the only ratio available will be 1A. 5. Set the Secondary ratio through the drop down menu next to Tap. The available ratios are determined by the selected CT type. 6. Optional: Select the number of phases from the drop down menu next to No. Phases. 7. Optional: Choose a Y or D connection for the secondary side winding. This field is only available for a 2- or 3-phase CT. 8. Optional: If the CT is 1 or 2-phase, the measured phases must be selected. These can be: • a, b or c phase current; • 𝑁 = 3 · 𝐼0 ; or • 𝐼0 = 𝐼0 9. Optional: If the CT is 3-phase, select the Phase Rotation. This defines how the phases of the secondary side map to the phases of the primary side. For example, if you wanted the A and B Phases to be flipped on the secondary side of the transformer, then you would choose a Phase Rotation of “b-a-c". If it is desired to model CT saturation, saturation information about the CT can be entered on the “Additional Data" page of the CT element. This information is used only when the “detailed model" tick box is selected, otherwise it is ignored by the calculation engine. DIgSILENT PowerFactory 15, User Manual

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Configuring the current transformer type

The current transformer type dialogue, as depicted in Figure 39.3.3, defines the single phases of a CT. The information about the connection of phases (Y or D) is defined in the CT element as discussed in Section 39.3.3.

Figure 39.3.3: The Current Transformer Type dialogue

To add additional Primary or Secondary Taps: 1. Right-click one of the cells in the tabular list of available taps. A menu will appear. 2. Choose Insert Row/s, Append Row/s or Append n Rows to add one or more rows to the table. 3. Enter the ratio of the tap. Note the tabular list must be in ascending order. Optionally, you might like to add some additional information about the CT on the Additional Data page. Information entered on this page is not calculation relevant and is provided for documentation purposes only. The following accuracy parameters can be selected: • The accuracy class • The accuracy limit factor • either – The apparent power (acc. to IEC) – The burden impedance (ANSI-C) – The voltage at the acc. limit (ANSI-C)

39.3.3.2

Configuring a CT as an auxiliary unit or changing the measurement location

By default the CT measures the current within its parent cubicle. The Location fields Busbar and Branch show information about the measurement location automatically. However, it is possible to configure the CT to measure current in a different location. To do this: 882

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icon next to Cubicle. A data browser will appear.

2. Select either another cubicle, a switch or another CT where you would like to measure current. If you select another CT, then this CT becomes an auxiliary CT with the final ratio from the primary circuit to the CT secondary side the product of the ratios of the two CTs - this is indicated in the field Complete Ratio. If you select another cubicle or switch then the CT will measure current at location of the selected switch or cubicle.

39.3.4

Configuring the voltage transformer

A voltage transformer (VT) can be created as described in section 39.2.2. Alternatively a VT can be created by using the Create VT button in the relay element dialogue. The dialogue as depicted in Figure 39.3.4 will then pop up.

Figure 39.3.4: The Voltage Transformer dialogue

The process of configuring the VT is then: 1. Select the VT type. Refer to Section 39.3.4.1 for information about the VT type. 2. Optional: If you would like to setup the VT to measure a location other than its parent cubicle or as an auxiliary VT, you can choose this through the Location selection icon. Refer to Section 39.3.4.4 for further instructions. 3. Set the Primary ratio through the drop down menu next to Tap. The available ratios are determined by the selected VT type. If no type is selected, the available ratios will be 1, 100, 110, 120 and 130. 4. Optional: Choose a YN, D or V (two phase) connection for the primary winding. If the “V" option is selected then the VT is connected as shown in Figure 39.3.6. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 39. PROTECTION 5. Optional: Set the secondary winding type. If no type is selected, the available ratios will be 1, 100, 110, 120 and 130. More information about the secondary type can be found in Section 39.3.4.2. 6. Set the Secondary ratio through the drop down menu next to Tap. The available ratios are determined by the selected VT type. 7. Optional: Choose a YN, D or O (open delta) connection for the primary winding. If “O" is selected, the VT secondary winding measures zero sequence voltage only with the winding configured as shown in Figure 39.3.5. 8. Optional: Click Additional Secondary Windings to open a dialogue where extra secondary windings can be added. See Section 39.3.4.3 for more information about configuring additional secondary windings. When a VT is created it is stored in the cubicle that was right-clicked or the cubicle the relay is stored in.

Figure 39.3.5: The open delta (O) winding connection

Figure 39.3.6: The V winding connection

39.3.4.1

The voltage transformer type

The voltage transformer type, as depicted in Figure 39.3.7 defines the type of voltage transformer and the ratio of the primary winding.

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Figure 39.3.7: The voltage transformer type dialogue

The voltage transformer can be configured as: Ideal Voltage Transformer In this case no saturation or transformer leakage impedance values are considered and the voltage transformer has a perfect transformation of primary measured values into secondary quantities. Voltage Transformer In this case saturation and transformer leakage effects are modelled according to data entered on the Transformer Data page. Capacitive Voltage Transformer In this case, the VT is modelled as a CVT according to the parameters entered on the Transformer Data and Additional CVT Data page. To configure additional Primary Taps: 1. Right-click one of the cells in the tabular list of available taps. A menu will appear. 2. Choose Insert Row/s, Append Row/s or Append n Rows to add one or more rows to the table. 3. Enter the ratio of the tap. Note the tabular list must be in ascending order.

39.3.4.2

Configuring the secondary winding type

The secondary winding is defined by the secondary winding type, and is similar to the primary VT type where multiple Secondary Tap ratios can be defined. The basic data page of the secondary winding type is shown in Figure 39.3.8. If a secondary winding is not selected, it has the standard tap settings of 1, 100, 110, 120 and 130V available. The burden and power factor on this page are not calculation relevant and for information purposes only. Therefore, the secondary winding type is always treated as an ideal transformer.

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Figure 39.3.8: The VT secondary winding type dialogue

39.3.4.3

Additional VT secondary winding types

In some cases a VT has multiple secondary windings. For example, some VTs might have a regular winding and then also an ’open delta’ winding for measuring the zero sequence voltage. It is possible to configure a PowerFactory VT in the same way. To define an additional secondary winding type: 1. Click the VT element Additional Secondary Windings button. 2. Click the button. A dialogue for the Secondary Voltage Transformer will appear as shown in Figure 39.3.9. 3. Click the

button.

4. Choose Select Project Type. . . . The type is a secondary winding type as described in Section 39.3.4.2. 5. Choose the Tap. 6. Select the Connection.

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Figure 39.3.9: The VT secondary winding dialogue

39.3.4.4

Configuring the VT as an auxiliary VT or changing the measurement location

By default the VT measures the voltage within its parent cubicle. The Location fields Busbar and Branch show information about the measurement location automatically. However, it is possible to configure the VT to measure in a different location. To do this: 1. Click the

icon next to Location. A data browser will appear.

2. Select either another cubicle, a bus or another VT where you would like to measure voltage. If you select another VT, then this VT becomes an auxiliary VT with the final ratio from the primary circuit to the VT secondary side the product of the ratios of the two VTs - this is indicated in the field Complete Ratio. If you select another cubicle or busbar then the VT will measure voltage at location of the selected switch or cubicle.

39.3.5

How to add a fuse to the network model

In PowerFactory the fuse element operates to some extent like an inverse time over-current relay with a 1/1 CT. The fuse will “melt" when the current in the fuse element exceeds the current specified by the fuse’s melt characteristic. To add a fuse to the network model: 1. Either: (a) Right-click a target cubicle and select the option New Devices → Fuse . . . . This is an internal (or implicit fuse) located within the cubicle. Or: (b) Add an explicit fuse model to the network by clicking the you would connect a line or transformer. 2. On the fuse dialogue (Figure 39.3.10), click the

and connecting the device as

button and either:

(a) Select Global Type. A dialogue will appear showing you a library of built-in fuses where you can select an appropriate one; or (b) Select Project Type. A dialogue will appear showing you the local project library where you can choose a fuse type that you have created yourself or downloaded from the DIgSILENT website. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 39. PROTECTION 3. Adjust other options on the basic data page. The options are as follows: Closed If this is checked, the fuse will be in the closed (non melted) state for the calculation. Open all phases automatically If this option is enabled, then should the fuse be determined to melt, PowerFactory will automatically open all three phases on the switch during a time domain simulation or short circuit sweep. This field has no effect on the load-flow or shortcircuit calculations. No. of Phases This field specifies whether the fuse consists of three separate fuses (3 phase), two fuses (2 phase) or a single fuse (1 phase). Note, when the one or two phase option is selected and the fuse is modelled explicitly in the network model, the actual phase connectivity of the fuse is defined within the cubicles that connect to the fuse. When the fuse is modelled implicitly, a selection box will appear that allows you to select which phase/s the fuse connects to. Fuse type This field is used for information and reporting purposes only. Device Number This field is used for information and reporting purposes only. Compute Time Using Many fuses are defined using a minimum melt curve and a total clear curve as illustrated in Figure 39.3.11 - the idea is that for a given current, the fuse would generally melt at some time between these two times. In PowerFactory it is possible to choose whether the trip/melt time calculations are based on the minimum melt time or the total clear time.

Figure 39.3.10: The fuse model basic data dialogue

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Figure 39.3.11: Fuse melt characteristics

39.3.5.1

Fuse model setup - other pages

On the VDE/IEC Short-Circuit and Complete Short-Circuit pages there is the option to configure the fuse Break Time. This variable is used in the short circuit calculation of “Ib" when the Used Break Time variable is set to local, or min. of local. Refer to Chapter 22 for more information on the calculation of short circuits in PowerFactory. On the Optimal Power Flow page, there is the option Exclude from Optimization which if checked means that the fuse will be ignored by the OPF and open tie optimization algorithms. See Chapter 35 for further information. On the Reliability page, the fuse can be configured for Fault separation and power restoration. These options are explained in detail in Chapter 31.

39.3.6

Basic relay blocks for overcurrent relays

Section F.1 explained that all relay models contain slots which are placeholders for block (protection function) definitions. There are many types of protection blocks in PowerFactory and each type has a different function. Furthermore, there are various options and parameters within each of these blocks that enable mimicking in detail the functionality offered by many relays. The complete relay model is completed by interconnecting these different slots containing block definitions in various ways. Hence it is possible to produce relay models with a large variety of operating characteristics. Advanced users are able to define their own types of protection device. The creation of user defined protection devices is covered in the Section 39.11. The blocks contained within a relay are listed in the slot definition section of the relay model dialogue. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 39. PROTECTION In general the user will need to define parameters within these relay blocks. The settings dialogue can be reached by double clicking on the block of interest in the net elements column. If the user is interested in viewing a graphical representation of the interconnection of slots for a particassociated with the relay in the data manager. ular relay then the user should find the following icon By right clicking on this icon and selecting show graphic, a graphical representation of the relay frame will appear in a new window. The following sections provide a brief overview of some of the basic protection blocks that can be used to develop a relay model in PowerFactory. Further information about these blocks can be found in the protection block technical references which are available for download from the user support area of the DIgSILENT website.

39.3.6.1

The measurement block

The measurement block takes the real and imaginary components of the secondary voltages and currents from the VTs and CTs, and processes these into the quantities used by other protection blocks in the relay model. Quantities calculated by the measurement block include absolute values of each current and voltage phase and the positive and negative sequence components of voltage and current. Depending on how the measurement block type is configured, it also allows for the selection of different nominal currents and voltages. For example, this feature can be utilised to support relays that have both 1A and 5A versions. If a relay does not need a nominal voltage, for instance an overcurrent relay without directional elements, or if there is only one nominal value to choose from, the nominal voltage and/or current selection field is disabled.

Figure 39.3.12: Measurement block

For EMT simulations, the measurement block type can also be configured for different types of signal processing. This determines what type of algorithm is used for translating the input current and voltage waveforms into phasor quantities for use by the protection blocks. Various DFT and FFT functions along with harmonic filtering are available. Further information about the measurement block can be found in the technical reference on the block available from the support area of the DIgSILENT website.

39.3.6.2

The directional block

A detailed discussion of the principles of directional protection is outside the scope of this user manual. The reader is encouraged to refer to a protection text for more information on the general principles. A very brief high level overview is presented in the following paragraphs. In PowerFactory , there are two directional blocks the “RelDir" and the “RelDisDir". The “RelDir" block is the basic direction block and is typically used by over-current relay models to determine the direction of the current flow. It provides a forward or reverse direction determination signal which can be fed into subsequent overcurrent blocks. The block can also send a trip signal. 890

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39.3. SETUP OF AN OVERCURRENT PROTECTION SCHEME In its normal operating configuration, the block is determining the direction by comparing the angle between a “polarization" voltage and an “operating" current phasor. Various polarization methods are supported by the block including common ones such as self and cross polarisation. The block also has a so-called Maximum Torque Angle (MTA). This is the angle by which the polarized voltage is rotated. Consequently, the forward direction is determined by the MTA ±Angle Operating Sector (often 180°). This principle is illustrated in Figure 39.3.13.

Figure 39.3.13: Directional relay principle diagram

The polarization quantity 𝐴𝑝𝑜𝑙 is rotated over the angle 𝑀𝑇 (MTA). The rotated polarization quantity 𝐴′𝑝𝑜𝑙 ±AOS defines a half plane which forms the forward operating plane. The block will produce a tripping signal if the operating quantity is detected in the selected direction, and if it exceeds the threshold operating current, illustrated by the semi-circle Figure 39.3.13. The second type of directional block in PowerFactory is the “RelDisDir", this is normally used with distance protection relays and is discussed in Section 39.5.3.8. More details about the polarization methods and the tripping conditions can be found in protection technical references for these blocks available from the support area of the DIgSILENT website.

39.3.6.3

The instantaneous overcurrent block

The instantaneous overcurrent block is a protection block that trips based on current exceeding a set threshold (pickup current setting). The block also supports the inclusion of an optional delay time and directional features. Hence this block can be used to represent instantaneous, definite time and directional overcurrent relay functionality. The available setting ranges for the pickup and the time delay are defined within the type. The relay characteristic is shown in Figure 39.3.14. The total tripping time is the sum of the delay time and the pickup time also configured within the relay type.

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Figure 39.3.14: Instantaneous overcurrent tripping area

Figure 39.3.15 shows a screenshot of the PowerFactory block.

Figure 39.3.15: Instantaneous overcurrent block

The block will not reset until the current drops under the reset level, which is specified by the relay type in percent of the pickup current: Ireset=IpsetKr/100%. See Figure 39.3.16 for a typical timing diagram.

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Figure 39.3.16: Instantaneous overcurrent timing diagram

39.3.6.4

The time overcurrent block

The time-overcurrent block is a protection block that trips based on current exceeding a threshold defined by an I-t characteristic. Most relays support the selection of several different I-t characteristics. These characteristics can be shifted for higher or lower delay times by altering the time settings or shifted for higher or lower currents by altering the pickup current. The ranges for these two settings and the characteristics of the I-t curve are defined within the block type. Typical curves are shown in Figure 39.3.17.

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Figure 39.3.17: I-t curves for different time dials

An example of the time overcurrent block is shown in Figure 39.3.18.

Figure 39.3.18: Time overcurrent block

The pickup current defines the nominal value Ip which is used to calculate the tripping time. The I-t curve definition states a minimum and a maximum per unit current. Lower currents will not trip the relay (infinite tripping time), higher currents will not decrease the tripping time any further. These limits are shown in Figure 39.3.19. 894

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Figure 39.3.19: I-t curve limits

The pickup current may be defined by the relay type to be a per unit value, or a relay current. The nominal current defined by the measurement block (refer to Section 39.3.6.1) is used to calculate Ip. In the case of a per unit value, the relay current value already equals Ip. Altering the pickup current will thus not change the I-t curve, but will scale the measured current to different per unit values. The following example may illustrate this: • Suppose the minimum current defined by the I-t curve is imin=1.1 I/Ip. • Suppose the measurement unit defines Inom=5.0 rel.A. • Suppose pickup current Ipset=1.5 p.u. – relay will not trip for 𝐼 < 1.10 · 1.5 · 5.0𝑟𝑒𝑙.𝐴 = 8.25𝑟𝑒𝑙.𝐴 • Suppose pickup current Ipset=10.0 rel.A – relay will not trip for 𝐼 < 1.1 · 10.0𝑟𝑒𝑙.𝐴 = 11.0𝑟𝑒𝑙.𝐴

39.3.6.5

The logic block

The logic block in PowerFactory is responsible for two functions in the relay. Firstly, it combines the internal trip signals from the other functional blocks, either with logical AND or OR functions and produces an overall trip status and time for the relay in a single output. Secondly, it controls one or more switches in the power system model that will be opened by the relay in the time determined by the logical combination of the various tripping signals. If the relay is located in a cubicle and no switch is explicitly specified within the logic block, the default behaviour is for the logic block to open the switch within that cubicle. See Figure 39.3.20 for an example of the logic block settings dialogue.

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Figure 39.3.20: Logic block

39.4

The time-overcurrent plot

The time-overcurrent plot (VisOcplot) can be used for graphical analysis of an overcurrent protection scheme to show multiple relay and fuse characteristics on one diagram. Additionally, thermal damage curves for lines and transformers can be added to the plot along with motor starting curves. These plots can be used to determine relay tripping times and hence assist with protection coordination and the determination of relay settings and fuses’ characteristics. For simplified reporting of protection schemes, the time-overcurrent plot also supports visualisation of the network diagram next to the plot like that illustrated in Figure 39.4.1. This diagram also shows the relevant protection relays and instrumentation transformers with a colour scheme that matches the colour settings of the main diagram to enable easy identification of protection devices, their characteristics and their position in the network being analysed.

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39.4. THE TIME-OVERCURRENT PLOT

10000

100

1

0.01 275.00 kV 1 11.00 kV

10

100

100 1000 Source\Cub_1\TX HV O/C protection Bus A\Cub_1\B O/C protection Transformer

1000

10000

10000 100000 Bus A\Cub_2\TX EF prot Fuse Cable

Figure 39.4.1: Time-overcurrent plot showing the auto-generated graphic for the protection path

39.4.1

How to create a time-overcurrent plot

There are four different methods to create a time-overcurrent plot (VisOcplot). You can create this plot by right clicking the cubicle, the power system object, the protection device or the protection path. The first three methods do not show the protection single line diagram to the left of the plot, while the fourth method shows it. These methods are explained in further detail in the following sections. 1. From the cubicle (a) Right-click a cubicle containing overcurrent relays or fuses. The context sensitive menu will appear. (b) Select the option Create Time-Overcurrent Plot. PowerFactory will create a diagram showing the time-overcurrent plot for all protection devices and fuses within the cubicle. See Section 39.4.7 for how to configure the presentation of the plot. 2. From the power system object (line, cable, transformer) (a) Select one or more objects such as transformers or lines. The context sensitive menu will appear. (b) Select the option Show → Time-Overcurrent Plot. PowerFactory will create a diagram showing the time-overcurrent plot with the defined cable/line or transformer overload characteristic. 3. From the protection device (a) Open a tabular view of the protection device either from the list of calculation relevant objects or in the data manager. (b) Right click the

icon. A context sensitive menu will appear.

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CHAPTER 39. PROTECTION (c) Select Show → Time-Overcurrent Plot. 4. From the protection path (a) Navigate to the protection path in the data manager. (b) Right-click the

icon. A context sensitive menu will appear.

(c) Select Show → Time-Overcurrent Plot. Refer to section 39.7 (The time-distance plot) for more information on defining paths. In this case the time-overcurrent plot will also show an auto-generated schematic of the path to the left of the diagram. This plot can also be manually adjusted. Refer to Section 39.4.7. In methods 1-3, it is also possible to select the option Add to Time-Overcurrent Plot instead of Show → Time-Overcurrent Plot. This will open a list of previously defined over current plots from which any one can be selected to add the selected device to. Note: To show the relay locations and thus to visualize cubicles containing relays, you can set the colour representation of the single-line diagram to Relay Locations. If one of these locations is then right-clicked, the option Show → Time-Overcurrent Plot is available.

39.4.2

Understanding the time-overcurrent plot

The time-overcurrent plot shows the following characteristics: • Time-current characteristics of relays; • Time-current characteristics of fuses, including optionally the minimum and maximum clearing time; • Damage curves of transformers, lines and cables; • Motor starting curves; and • The currents calculated by a short-circuit or load-flow analysis and the resulting tripping times of the relays. • If defined from a path, then the simplified single line graphic showing the main power system objects, the protection devices and instrumentation transformers is displayed on the left of the diagram. See Figure 39.4.1 for an example.

39.4.3

Showing the calculation results on the time-overcurrent plot

The time-overcurrent plot shows the results of the short-circuit or load-flow analysis automatically as a vertical ’x-value’ line through the graph. Because the current ’seen’ by each device could be different (due to parallel paths, meshed networks etc), a current line is drawn for each device that measures a unique current. If the intersection of the calculated current with the time-overcurrent characteristic causes the shown characteristic to trip, then the intersection is labelled with the tripping time. These lines automatically update when a new load-flow or short-circuit calculation is completed.

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39.4.4

Displaying the grading margins

To show a ’grading margin’ line, which shows the difference between the tripping times of each protection device: 1. Right-click the time-overcurrent plot. A context sensitive menu will appear. 2. Select the option Show → Grading Margins. A dialogue box will appear. 3. Enter the desired position of the vertical line in the ’Value’ field. Note this can later be adjusted by dragging with the mouse. 4. Optional: Adjust the curve Colour, Width and Style to your preferences. 5. Optional: Choose the ’type’ of the current from the radio selection control. 6. Optional: Select ’User-defined’ and enter a custom label for the curve.

10

I = 12.032

DIgSILENT

7. Press OK to show the grading margins on the plot. An example with the grading margins shown using the default blue coloured curve is shown in Figure 39.4.2

I =268.581 3*I0 I =469.992 =479.667

1.220

0.000

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0.437 0.783 0.610

0.173 0.000 0.290

0.320

0.1 275.00 kV 1 11.00 kV

10 100 1000 Source\Cub_1\TX HV O/C protection Bus A\Cub_1\B O/C protection Transformer

100

0.000

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10000 100000 Bus A\Cub_2\TX EF prot Fuse Cable

Figure 39.4.2: Time-overcurrent plot with grading margins displayed in blue Note: The displayed grading margins shown by this method are the calculated grading margins based on the relay settings and the calculated current. ’Predicted’ grading margins can also be shown when dragging the sub-characteristics to alter the settings. Refer to Section 39.4.9.2.

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39.4.5

Adding a user defined permanent current line to the time-overcurrent plot

There are two ways to create a permanent vertical line on the time-overcurrent plot: 1. From any existing calculated short-circuit or load-flow calculated line: (a) Right-click the line. A context sensitive menu will appear. (b) Choose the option Set user defined. The line will now remain on the diagram when the calculation is reset or another calculation is completed. (c) Optional: Double-click the user defined line to edit its colour, width, style and alter the displayed label. (d) Optional: It is possible to drag the line using the mouse to alter its position on the diagram. 2. A new line not based on an existing calculation: (a) Right-click the time-overcurrent plot avoiding clicking on any existing curve or characteristic. (b) Choose the option Set Constant → x-Value. A dialogue will appear that allows you to configure the properties of the line. (c) Optional: Adjust the line properties such as width, colour, style and set a user defined label. (d) Press OK to add the line to the diagram.

39.4.6

Configuring the auto generated protection diagram

The auto-generated protection diagram that is created when a time-overcurrent diagram is generated from the protection path (see option 4 in Section 39.4.1) can also be manually adjusted by the user. To edit this graphic: 1. Right-click the protection diagram within the time-overcurrent plot; 2. Select the option Edit graphic in new Tab. A single line graphic showing the diagram will appear in a new tab. The diagram can be edited like a regular PowerFactory single line diagram and it will automatically update in the time-overcurrent plot following any changes.

39.4.7

Overcurrent plot options

To access the time-overcurrent plot settings, either: 1. Right-click the time-overcurrent plot and select Options; or 2. Double-click the time-overcurrent plot and click Options underneath the Cancel button in the displayed dialog.

39.4.7.1

Basic options page

The basic options page of the time-overcurrent options dialogue shows the following: Current Unit The current unit may be set to either primary or secondary (relay) amperes. Show Relays This option is used to display only certain types of relay characteristics. For example, you might want to display only earth-fault relays on the diagram and ignore phase fault characteristics. This could be done be selecting the ’Earth Relays’ option. 900

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39.4. THE TIME-OVERCURRENT PLOT Characteristic This option defines whether the displayed curves also show the curves including the additonal circuit breaker delays. The default option All shows both the minimum clearing time (not including the breaker delay) and the total clearing time (including the breaker delay). It is possible also to display just one of these curves. An example is highlighted in Figure 39.4.2. Note that the breaker delay time is specified in the basic data of the switch type TypSwitch. Recloser Operation The different recloser stages can be shown simultaneously or switched off in the diagram. Display automatically This option is used to select how the calculated load-flow or short-circuit currents will be displayed. Either the current lines, the grading margins, both or none may be selected. Consider Breaker Opening Time This option determines whether the relay characteristics will also include the breaker (switch) operating time. Voltage Reference Axis More than one current axis may be shown, based on different voltage levels. All voltage levels found in the path when a time overcurrent plot is constructed are shown by default. A user defined voltage level may be added. Optionally, only the user defined voltage level is shown. Cut Curves at This option determines the maximum extent of the displayed characteristics. For the default option ————-, the displayed curves continue past the calculated short-circuit or loadflow current to the extent of the defined characteristic. If the option Tripping current is selected, only the part of the curve less than the tripping current is displayed. The third option, Max. ShortCircuit/Rated Breaking Current means the curves will be displayed to the extent of the maximum current defined within the Max/Min Fault Currents page within the protection device.

DIgSILENT

Show Grading Margins while Drag&Drop When dragging curves, the grading margins of the curve will be shown according to the margin entered. Refer to Section 39.4.9.2 for more information on grading margins when dragging the time-overcurrent characteristics. I =11749.806 pri.A

100

[s]

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Total clearing time including circuit breaker delay.

1 0.690 s 0.610 s Minimum clearing time without circuit breaker delay.

0.1 11.00 kV 100 275.00 kV

1000 10 Bus A\Cub_1\B O/C protection

10000 100

[pri.A]

100000

1000

Figure 39.4.3: time-overcurrent plot showing an overcurrent characteristic including also the breaker delay time. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 39. PROTECTION 39.4.7.2

Advanced options page

Drag & Drop Step Sizes These are used to set the step change in the relay settings when a timeovercurrent plot is dragged with a continuous time dial or pickup current. Time Range for Damage Curves This option defines the maximum and minimum time limits for the transformer and line damage curves. ’Colour for Out of Service’ Units The characteristics for units that are out of service are invisible by default. However, a visible colour may be selected. Brush Style for Fuses This defines the fill style for fuse curves when they have a minimum and maximum melting time defined. Number of points per curve The number of plotted points per curve can be increased to show additional detail, or reduced to speed up the drawing of the diagram. Thermal Image, Pre-fault Current In some time-overcurrent relay characteristics, the tripping time is dependent on the pre-fault current. This box allows the user to enter a custom value for the pre-fault current, or to use the automatically calculated load-flow current.

39.4.8

Altering protection device characteristic settings from the time-overcurrent plot

The time-overcurrent plots can be used to alter the relay characteristics graphically. This section describes various procedures used to alter such characteristics.

39.4.9

How to split the relay/fuse characteristic

Often a complete relay characteristic is determined from a combination of two or more sub-characteristics. For example, an overcurrent relay often has a time-overcurrent characteristic designed to operate for low fault currents and overloads and a definite time characteristic that is typically set for high fault currents. To alter relay characteristics graphically, every protection device must first be ’split’ so that all characteristics are visible on the time-overcurrent plot. Figure 39.4.4 shows an example of such an overcurrent relay before it is split (left plot) and after it is split (right plot).

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DIgSILENT

39.4. THE TIME-OVERCURRENT PLOT

10000

[s]

1000

100

10

1

0.1 11.00 kV 100 275.00 kV

1000 10 Bus A\Cub_1\B O/C protection

10000 100

[pri.A]

100000

[pri.A]

100000

1000

DIgSILENT

(a) Unsplit 10000

[s]

1000

100

10

1

0.1 11.00 kV 100 275.00 kV

1000 10 Bus A\Cub_1\B O/C protection

10000 100

1000

(b) Split

Figure 39.4.4: Overcurrent relay characteristics in the time-overcurrent plot DIgSILENT PowerFactory 15, User Manual

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CHAPTER 39. PROTECTION There are two methods to split a relay to show the sub-characteristics: 1. Method 1: (a) Right-click the characteristic. The context sensitive menu will appear. (b) Select the option Split. 2. Method 2: (a) Double-click the time-overcurrent plot avoiding any shown characteristics. (b) On the lower table section of the displayed dialogue check the Split Relay box next to the relays and fuses that need to be split. (c) Click OK to close the dialogue. Note: Fuses can also be split! When a fuse is split, the fuse characteristic can be dragged with the mouse to automatically change the fuse type to another fuse within the same library level.

39.4.9.1

Altering the sub-characteristics

The first step is to Split the relay characteristic. See Section 39.4.9. After this there are two different methods to alter the relay sub-characteristics: 1. By left clicking and dragging the characteristic. (a) Drag to the left to reduce the current setting or to the right to increase the current setting. (b) Drag to the top to increase the time setting or to the bottom to decrease the time setting. 2. By double-clicking a characteristic. (a) Double click the target characteristic. A dialogue for that characteristic will appear. (b) Enter time and current numerical settings directly in the available fields. (c) Optional: For time-overcurrent characteristics, the curve type (very inverse, standard inverse, extremely inverse) can also be selected. Note: Relay sub-characteristics cannot be dragged to positions outside the range defined within the relay type, nor can they be dragged diagonally to simultaneously alter the time and current setting.

39.4.9.2

Showing grading margins during characteristic adjustment

The time-overcurrent plot option dialogue (39.4.7), has an option for showing the grading margins. When this option is enabled, the grading margins will appear whenever a time-overcurrent sub-characteristic is dragged. These are represented as grey characteristics above and below the main sub-characteristic. The upper limit is defined by the characteristic operating time plus the grading margin and the lower limit of the envelope is defined by the characteristic operating time minus the grading margin. An example is illustrated in Figure 39.4.5. The original characteristic is labelled “1", the new position as “2", and the grading margins are labelled “a".

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39.4. THE TIME-OVERCURRENT PLOT

Figure 39.4.5: Grading margins when Moving a characteristic

39.4.10

Equipment damage curves

Equipment damage curves are used to aid the positioning of relay and fuse time-current characteristics to ensure that thermal damage to equipment is minimized in the event of an overload or short-circuit. The following types of damage curves exist: • Conductor damage curve • Transformer damage curve • Motor starting curve

39.4.10.1

How to add equipment damage curves to the time-overcurrent plot

There are two methods to add damage curves to an time-overcurrent plot. 1. Method 1: (a) Right-click a transformer or line object. A context sensitive menu will appear. (b) Select (Show → Time-overcurrent plot). 2. Method 2: (a) Right-click an existing time-overcurrent plot, avoiding any existing characteristics. A context sensitive menu will appear. (b) Select (Add → Transformer Damage Curve / Conductor/Cable Damage curve / Motor starting curve). A dialogue with options for configuring the damage curve will appear. See Sections 39.4.10.2, 39.4.10.3 and 39.4.10.4.

39.4.10.2

Transformer damage curves

The transformer damage curve dialogue is illustrated in figure 39.4.6, the user is able to add a damage curve in accordance with ANSI/IEEE C57.109. This standard differentiates between the damage DIgSILENT PowerFactory 15, User Manual

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CHAPTER 39. PROTECTION curve of a transformer which is expected to be subjected to frequent faults and one that is subjected to infrequent faults. In the former case, mechanical damage at high short circuit levels can be of significant concern. For category II and III transformers in particular, accounting for mechanical damage, significantly alters the damage characteristic of the transformer. An example of a time-overcurrent plot with two relay characteristics and a category II transformer damage curve for a transformer subjected to frequent faults is shown in Figure 39.4.7. The mechanical damage characteristic is ringed in the figure. If the user wishes to define an alternative damage curve this can be achieved by selecting User Defined curve → New project type, in the dialogue.

Figure 39.4.6: Transformer damage curve

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39.4. THE TIME-OVERCURRENT PLOT

Figure 39.4.7: Transformer damage curve

The transformer damage curve consists of four parts. Rated Current Curve The rated current curve represents the nominal operation limits of the transformer.

𝐼(𝑡) = 𝐼𝑟𝑎𝑡 =

𝑆𝑟𝑎𝑡 𝑈𝑟𝑒𝑓

(39.1)

Where: 𝐼𝑟𝑎𝑡

rated current of the line or the damage curve input value [A]

𝑆𝑟𝑎𝑡

inrush current to nominal current ratio [kVA]

𝑈𝑟𝑎𝑡

inrush duration [kV ]

Thermal and Mechanical Damage Curve The thermal and mechanical damage curve represents the maximum amount of (short-circuit) current the transformer can withstand for a given amount of time without taking damage. The transformer is classified into one of four possible groups, depending on its rated apparent power and the insulation type (see Table 39.4.1). Dry-type transformers can only be category I or II.

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CHAPTER 39. PROTECTION Classification

Three-Phase

Single-Phase

Category I Category II Category III Category IV

𝑆𝑟𝑎𝑡 ≤ 0.5𝑀 𝑉 𝐴 𝑆𝑟𝑎𝑡 ≤ 5.0𝑀 𝑉 𝐴 𝑆𝑟𝑎𝑡 ≤ 30.0𝑀 𝑉 𝐴 𝑆𝑟𝑎𝑡 > 30.0𝑀 𝑉 𝐴

𝑆𝑟𝑎𝑡 ≤ 0.5𝑀 𝑉 𝐴 𝑆𝑟𝑎𝑡 ≤ 1.667𝑀 𝑉 𝐴 𝑆𝑟𝑎𝑡 ≤ 10.0𝑀 𝑉 𝐴 𝑆𝑟𝑎𝑡 > 10.0𝑀 𝑉 𝐴

Table 39.4.1: Categories for Transformers

The thermal damage part of the curve is identical for all categories of the respective insulation type and is shown in Table 39.4.2. (taken from IEEE Standards Board, IEEE Guide for Liquid-Immersed Transformer Through-Fault-Current Duration, New York: The Institute of Electrical and Electronics Engineers, Inc., 1993. and IEEE Guide for Dry-Type Transformer Through-Fault Current Duration, New York: The Institute of Electrical and Electronics Engineers, Inc., 2002. ) Liquid-Immersed 𝐼/𝐼𝑟𝑎𝑡 𝑡[𝑠] 25 11.3 6.3 4.75 3 2

2 10 30 60 300 1800

Dry-Type 𝐼/𝐼𝑟𝑎𝑡 𝑡[𝑠] 25 3.5

2 102

Table 39.4.2: Thermal Withstand Capabilities

ANSI Mechanical Damage Curve The mechanical part of the ANSI damage curve is only available for transformers of category II and higher. For transformers of categories II and III this part is optional and depends on expected number of fault currents flowing through the transformer over the transformers lifetime. Typically the mechanical part should be considered if the transformer is expected to carry fault current more than 10 (category II) or 5 (category III) times during its lifecycle. For category IV transformers the mechanical part of the curve is always considered. See IEEE Standards Board, IEEE Recommended Practice for Protection and Coordination of Industrial and Commercial Power Systems, New York: The Institute of Electrical and Electronic Engineers, Inc., 1999, Page 426. The mechanical part of the damage curve is a shifted part of the thermal damage curve. The three points necessary to draw the mechanical damage curve can be calculated as follows:

1 ; 𝑡1 = 2, 0𝑠 𝑢𝑘

(39.2)

𝑐𝑓 𝐾 𝐼1 2 · 𝑡1 2, 0𝑠 ; 𝑡2 = 2 = = 2 𝑢𝑘 𝑐𝑓 2 𝐼2 𝐼2

(39.3)

𝐼1 ) = 𝐼𝑟𝑎𝑡 ·

𝐼2 ) = 𝐼𝑟𝑎𝑡 ·

𝐼3 = 𝐼2 ; 𝑡3 = 𝑖𝑛𝑡𝑒𝑟𝑠𝑒𝑐𝑡𝑖𝑜𝑛 𝑤𝑖𝑡ℎ 𝑡ℎ𝑒𝑟𝑚𝑎𝑙 𝑐𝑢𝑟𝑣𝑒 Where: 𝐼𝑟𝑎𝑡

rated current of the transformer [A]

𝑢𝑘

short-circuit voltage of the transformer [%]

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39.4. THE TIME-OVERCURRENT PLOT 𝐼 𝐼𝑟𝑎𝑡

· 𝑡 = 𝐾 = 𝑐𝑜𝑛𝑠𝑡.

𝑘

heating constant with

𝑐𝑓

fault current factor [-] −𝑐𝑓 = 0.7 for category II and 𝑐𝑓 = 0.5 for categories III and IV

ANSI Curve Shift The damage curve is based on a three phase short-circuit on the LV-side of the transformer. In case of unbalanced faults (Ph-Ph, Ph-E, Ph-Ph-E) the phase current on the HV side may be distributed over multiple phases, depending on the vector group of the transformer. The standard (IEEE Standards Board, IEEE Recommended Practice for Protection and Coordination of Industrial and Commercial Power Systems, New York: The Institute of Electrical and Electronic Engineers, Inc., 1999.) therefore suggests to multiply the rated current of the transformer by a shifting factor, thus enabling the engineer to archive proper protection of a transformer for unbalanced faults. While the shift is only applicable for “Dyn" vector-groups (according to the cited standard) and single-phase to ground faults, the same principle of current reduction on the HV side also applies to other vector groups. The resulting shifting factors and the corresponding fault type can be taken from Table 39.4.3. Vector Group(s)

Shift Factor

Fault Type

Dd Dyn/Dzn Yyn/Zyn/Zzn

0,87 0,58 0,67

Ph-Ph Ph-E Ph-E

Table 39.4.3: ANSI Curve Shift Factors

IEC Mechanical Damage Curve The mechanical part of the IEC damage curve is only available for the element specific damage curve and consists of one point only [10]:

𝐼(2, 0𝑠) = 𝐼𝑟𝑎𝑡 ·

1 𝑢𝑘

(39.4)

Where: 𝐼𝑟𝑎𝑡

rated current of the transformer [A]

𝑢𝑘

short-circuit to nominal current ratio [%]

Cold load curve The cold load curve represents the maximum amount of current a transformer can withstand for a shorttime (typically several minutes) before taking damage. The curve is specific for each transformer and the supplied loads and has to be provided by the user as a series of (I/t) pairs. Inrush peak current curve The inrush curve represents the amount of current which flows into the transformer when the transformer is energised. The curve is represented by a straight line between the following two points:

[1]

[1]

𝐼(𝑇𝑖𝑛𝑟𝑢𝑠ℎ ) = 𝐼𝑟𝑎𝑡 ·

𝐼𝑖𝑛𝑟𝑢𝑠ℎ 𝐼𝑛𝑜𝑚

(39.5)

[2]

[2]

𝐼(𝑇𝑖𝑛𝑟𝑢𝑠ℎ ) = 𝐼𝑟𝑎𝑡 · DIgSILENT PowerFactory 15, User Manual

𝐼𝑖𝑛𝑟𝑢𝑠ℎ 𝐼𝑛𝑜𝑚

(39.6) 909

CHAPTER 39. PROTECTION Where: 𝐼𝑟𝑎𝑡 𝐼𝑖𝑛𝑟𝑢𝑠ℎ 𝐼𝑛𝑜𝑚

𝑇𝑖𝑛𝑟𝑢𝑠

rated current of the transformer [A] inrush current to nominal current ratio [-] inrush duration [s]

Note: If only one of the two points is given, only this point is drawn. Three Winding Transformers The transformer damage curve can be used for 3-winding transformers. On the protection page of the NetElement, a drop-down box is available which allows the user to select which set of values (HV-MV (default), HV-LV, MV-LV) should be used to calculate the curve. The equations remain identical, as there are normally only two windings within a coordination path.

39.4.10.3

Conductor/cable damage curves

The conductor damage curve consists of four parts; a rated current curve, a short-time withstand curve, a long time overload curve and an inrush curve. These components are discussed in the following text. Rated Current Curve The rated current curve represents the nominal operation limits of the conductor.

(39.7)

𝐼(𝑡) = 𝐼𝑟𝑎𝑡 Where: 𝐼𝑟𝑎𝑡

rated current of the line [A]

Short-Time Withstand Curve The short-time withstand curve represents the maximum amount of (short-circuit) current the conductor can withstand for short time periods (typically 1s) without taking damage. There are two separate equations for this curve, both are drawn for 0.1s ≤ t ≤ 10s Using the rated short-time withstand current:

√︂ 𝐼(𝑡) = 𝐼𝑡ℎ𝑟 ·

𝑇𝑡ℎ𝑟 𝑡

(39.8)

Where: 𝐼𝑡ℎ𝑟

rated short-time current of the line [A]

𝑇𝑡ℎ𝑟

rated short-time duration of the [s]

Using material data (only available for the generic type):

𝐼(𝑡) =

910

𝐹𝑎𝑐 · 𝑘 · 𝐴 √ 𝑡

(39.9)

DIgSILENT PowerFactory 15, User Manual

39.4. THE TIME-OVERCURRENT PLOT Where: 𝐹𝑎

lateral conductivity [-]

𝐴

conductor cross-sectional area [𝑚𝑚2 /𝑘𝑐𝑚𝑖𝑙]

𝑘

𝐴 𝑠 𝐴 𝑠 conductor/insulation parameter [ 𝑚𝑚 2 / 𝑚𝑚2 𝑘𝑐𝑚𝑖𝑙]

√

√

The conductor/insulation parameter can be provided by the user or calculated according to the standards equations as follows: IEC/VDE equations [18]:

√︂ 𝑘 = 𝑐1 ·

ln(1 +

𝜃𝑓 − 𝜃𝑖 ) 𝑐2 + 𝜃𝑖

(39.10)

ANSI/IEEE equations [3]:

√︂ 𝑐1 · log

𝑘=

𝜃𝑓 + 𝑐2 𝜃𝑖 + 𝑐2

(39.11)

Where: 𝑐1

material constant [-]

𝑐2

material constant [-]

𝜃𝑓

max. short-circuit temperature [∘ C]

𝜃𝑖

initial temperature [∘ C]

Note: Both equations for the conductor/insulation parameter are slightly adapted (from the original form in the standards) to fit into the same form of equation. The values for the material constants can be taken from the table below. Standard Conductor Material 𝑐1 𝑐2

IEC/VDE Copper 226 234.5

Aluminium 148 228

ANSI/IEEE Copper 0.0297 234

Aluminium 0.0125 228

Table 39.4.4: Material Constants for Short-Term Withstand Calculation

The initial temperature and final temperature 𝜃𝑖 and 𝜃𝑓 mainly depend upon the insulation of the conductor. The initial temperature is usually the maximum allowable continuous current temperature, whilst the final temperature is the maximum allowable short circuit temperature. Typical values for 𝜃𝑖 and 𝜃𝑓 are given in table 39.4.5.

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CHAPTER 39. PROTECTION Cable insulation and type

Initial temperature (∘ C)

Final temperature (∘ C)

1-6kV: belted 10-15kV: belted 10-15kV: screened 20-30kV: screened PVC: 1 and 3kV

80 65 70 65

160 160 160 160

Up to 300mm2 Over 300mm2 XLPE and EPR

70 70 90

160 140 250

Paper

Table 39.4.5: Typical cable initial temperature and final temperature values (data from the BICC Electric Cables Handbook 3rd edition)

The option user defined may also be selected in the calculate K field of the dialogue, allowing the user to enter a value for K manually. The dialogue for doing this is illustrated in figure 39.4.8.

Figure 39.4.8: Conductor/Cable damage curve

Alternatively, rated short-circuit current and time may be entered if Rated Short-Time Current is entered as the input method. If the user wishes to define an alternative conductor/cable damage curve this can be achieved by selecting User Defined curve → New project type. Skin effect ratio or ac/dc ratio is a constant as defined in the NEC electrical code. The value is used when carrying out calculations to IEEE/ANSI standards and is not typically referred to by IEC/VDE 912

DIgSILENT PowerFactory 15, User Manual

39.4. THE TIME-OVERCURRENT PLOT standards. However, the user is given the option to specify this value when using either set of standards. Long time overload curve The overload page allows the user to define the overload characteristic of the conductor. If an overload characteristic is required, it is necessary to ensure that the draw overload curve checkbox is selected as illustrated in figure 39.4.9.

Figure 39.4.9: Overload curve settings

The user then has the option to define the overload curve according to ANSI/IEEE standards by selecting the relevant checkbox. The equation used is as follows:

𝐼𝐸 = 𝐼𝑁

⎯ (︁ )︁2 ⎸ 𝑡 ⎸ 𝑇𝐸 −𝑇0 − 𝐼0 · 𝑒− 𝑘 ⎷ 𝑇𝑁 −𝑇0 𝐼𝑁 1−

𝑡 𝑒− 𝑘

·

𝑇𝑀 + 𝑇𝑁 𝑇𝑀 + 𝑇𝐸

(39.12)

Where, 𝐼𝐸 = Max overload temperature 𝐼𝑁 = Normal current rating 𝐼0 = Preload current 𝑇𝐸 = Max overload temperature 𝑇𝑁 = Max operating temperature 𝑇0 = Ambient temperature 𝑇𝑀 = Zero resistance temperature value, (234 for copper, 228 for aluminium) 𝑘 = A constant dependant on cable size and installation type.

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CHAPTER 39. PROTECTION Note that the value for TM is derived from the material assigned in the short circuit page which is only visible when the field calculate k is set to ANSI/IEEE or IEC/VDE. If the checkbox is left unchecked the equation used is as follows:

𝐼𝐸 = 𝐼𝑁

⎯ (︁ )︁2 ⎸ 𝑡 ⎸ 1 − 𝐼0 · 𝑒− 𝑘 ⎷ 𝐼𝑁 𝑡

1 − 𝑒− 𝑘

(39.13)

Where the variables are the same as in the previous equation. A constant designated as tau is requested in the dialogue. This is identical to the constant k except k has units of hours, while tau has units of seconds. Inrush Curve The inrush curve represents the amount of current that will flow into the conductor when the conductor is energised. The curve consists of one point only.

𝐼(𝑇𝑖𝑛𝑟𝑢𝑠ℎ ) = 𝐼𝑟𝑎𝑡 ·

𝐼𝑖𝑛𝑟𝑢𝑠ℎ 𝐼𝑛𝑜𝑚

(39.14)

Where: 𝐼𝑟𝑎𝑡

rated current of the line or the damage curve input value [A]

𝐼𝑖𝑛𝑟𝑢𝑠ℎ 𝐼𝑛𝑜𝑚

inrush current to nominal current ratio [-]

𝑇𝑖𝑛𝑟𝑢𝑠ℎ

inrush duration [s]

39.4.10.4

Motor starting curves

A motor starting curve is illustrated in figure 39.4.10. It consists of two seperate components, a starting curve and a damage curve. This section describes the equations and references underpinning the two curves.

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39.4. THE TIME-OVERCURRENT PLOT

Figure 39.4.10: Motor start curve edit dialogue

The characteristic currents and durations given in the edit dialogue result in a step wise motor start current plot, as depicted in Figure 39.4.11.

Figure 39.4.11: The motor start curve

Motor starting curve equations DIgSILENT PowerFactory 15, User Manual

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CHAPTER 39. PROTECTION This section describes the underlying equations and references the respective standards. Note: The equations in this section are given with respect to the rated current of the equipment. For the correct drawing in the overcurrent plot, the currents will be rated to the reference voltage of the plot. 𝐼 = 𝐼𝑟𝑎𝑡 ·

𝑈𝑟𝑎𝑡 𝑈𝑟𝑒𝑓

(39.15)

The motor starting curve consists of three parts; a rated current curve, the motor starting curve and the motor inrush curve. Rated Current Curve The rated current curve represents the nominal operation limits of the motor and is drawn for 𝑇𝑠𝑡𝑎𝑟𝑡 < t.

𝐼(𝑡) = 𝐼𝑟𝑎𝑡 =

𝑆𝑟𝑎𝑡 𝑈𝑟𝑎𝑡

(39.16)

Where: 𝐼𝑟𝑎𝑡

rated current time of the motor [A]

𝑆𝑟𝑎𝑡

rated apparent power (electrical) of the motor [kVA]

𝑈𝑟𝑎𝑡

rated voltage of the motor [kV ]

𝑇𝑠𝑡𝑎𝑡

starting time of the motor [s]

Motor Starting Curve The motor starting curve represents the maximum amount of current that will flow into the motor while it accelerates. The curve is drawn for 𝑇𝑖𝑛𝑟𝑢𝑠ℎ < t ≤ 𝑇𝑠𝑡𝑎𝑟𝑡 :

𝐼(𝑡) = 𝐼𝑟𝑎𝑡 =

𝐼𝑙𝑟 𝐼𝑛𝑜𝑚

(39.17)

Where: 𝐼𝑟𝑎𝑡

rated current of the motor [A]

𝐼𝑙𝑟 𝐼𝑛𝑜𝑚

ratio of locked rotor current to nominal current of the motor [-]

𝑇𝑠𝑡𝑎𝑟𝑡

starting time of the motor [s]

𝑇𝑖𝑛𝑟𝑢𝑠ℎ

inrush duration [s]

Motor Inrush Curve The motor inrush curve represents the amount of current that will flow into the motor when it is energised. The curve is drawn from 0,01 s ≤ t ≤ 𝑇𝑖𝑛𝑟𝑢𝑠ℎ :

𝐼(𝑡) = 𝐼𝑟𝑎𝑡 = 916

𝐼𝑖𝑛𝑟𝑢𝑠ℎ 𝐼𝑛𝑜𝑚

(39.18)

DIgSILENT PowerFactory 15, User Manual

39.5. SETUP AND ANALYSIS OF A DISTANCE PROTECTION SCHEME Where: 𝐼𝑟𝑎𝑡

rated current of the motor [A]

𝐼𝑡𝑟 𝐼𝑛𝑜𝑚

ratio of inrush current to nominal current of the motor [-]

𝑇𝑖𝑛𝑟𝑢𝑠ℎ

inrush duration [s]

Motor Damage Curve The motor damage curve represents the maximum amount of current the motor can withstand for a given time without taking damage. There are two curves available, one representing the damage characteristic of the cold motor, one representing the damage characteristic of the hot motor. The hot curve must be lower than the cold curve. The curve would actually follow an inverse current-time characteristic but is reduced to a vertical line to indicate the damage region without cluttering the plot. The motor damage curve is drawn from 𝑇ℎ𝑜𝑡 ≤ t ≤ 𝑇𝑐𝑜𝑙𝑑 :

𝐼(𝑡) = 𝐼𝑟𝑎𝑡 · 𝐼𝑙𝑟

(39.19)

Where: 𝐼𝑟𝑎𝑡 𝐼𝑙𝑟

rated current of the motor [A] ratio of locked rotor current to rated current of the motor [-]

𝑇ℎ𝑜𝑡

stall time for the hot motor [s]

𝑇𝑐𝑜𝑙𝑑

stall time for the cold motor [s]

Synchronous Motors The motor starting curve can be created for synchronous motors. Since synchronous motors are started in asynchronous operation, the curve is identical to the asynchronous motor starting curve. The parameter mapping for the synchronous machine is as follows: Motor Curve Rated Power Rated Voltage Locked Rotor Current (Ilr/In)

Starting

Parameter Srat Urat aiazn

Asynchronous Motor

Synchronous Motor

Parameter t:sgn t:ugn t:aiazn

Parameter t:sgn t:ugn 1 / (t:xdsss)

Table 39.4.6: Synchronous Motor Parameter Mapping Note: By default the subtransient reactance (t:xdss) is used. If the flag “Use saturated values" in the machine type is set, the saturated subtransient reactance (t:xdsss) is used.

39.5

Setup and analysis of a distance protection scheme

Section 39.2.2, explains the procedure to setup a protection device in PowerFactory. When a new device is created within a network model there are a number of parameters to define in the dialogue DIgSILENT PowerFactory 15, User Manual

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CHAPTER 39. PROTECTION which appears. This section will describe the basic steps that should be completed in order to specify these parameters for distance protection relays. In many cases the setup is similar to overcurrent relay and consequently only the main differences are highlighted in this section. The following sections, 39.6 and 39.7 will cover the main graphical tools used for distance protection analysis in PowerFactory.

39.5.1

Distance relay model setup - basic data page

The basic data page in the relay model (ElmRelay ) dialogue is where the basic configuration of the relay is completed. The procedure is the same as that used for setting up the over-current relay. Refer to Section 39.3.1.

39.5.2

Primary or secondary Ohm selection for distance relay parameters

It is always possible to enter the reach setting/s of the distance mho (refer Section 39.5.3.3) and distance polygon (refer Section 39.5.3.4) blocks in terms of primary Ohms or secondary Ohms. However, for the purpose of the respective block types, and specifying the valid settings range, one of these quantities must be configured as the default mode. Normally this is secondary Ohms, however some relays may allow this to be primary Ohms and hence in PowerFactory it is possible to alter the default option. To do this: 1. Go to the Advanced data page of the relay type. 2. Choose either Secondary Ohm or Primary Ohm. 3. Press OK to close the relay type. There is another feature that is enabled if the Primary Ohm option is selected. This is the overriding of the CT and VT ratio determined from the selected VT and CT automatically with custom settings. To do this: 1. Enable the Primary Ohm option for impedance ranges as described above. 2. Select the Current/Voltage Transformer page of the relay element. 3. Click Set CT/VT ratio. 4. Enter the updated parameters of the CTs and VTs. This feature could be used for instance to quickly see the affect of altering the CT or VT ratio without having to modify the PowerFactory CT and VT objects.

39.5.3

Basic relay blocks used for distance protection

The following sections provide a brief overview of some of the basic protection blocks that can be found within distance relays in PowerFactory . Some of the protection blocks such as the measurement block, logic block, directional, and overcurrent blocks that were discussed in Section 39.3.6 are also used within distance relays. Consequently, this section only discusses those blocks that are unique to distance relays. By necessity, this manual only provides a brief high level overview of the blocks. Further technical information can be found in the protection block technical references which are available for download from the user support area of the DIgSILENT website.

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39.5. SETUP AND ANALYSIS OF A DISTANCE PROTECTION SCHEME 39.5.3.1

The polarizing block

The purpose of the “Polarizing" block is to provide “polarized" current and voltage signals to the distance protection zones (either Mho or Polygonal). The block takes as input the following signals: • Real and imaginary components of the three phase currents and voltages; • Real and imaginary components of the zero sequence currents; and • Optional: Real and imaginary components of the mutual zero sequence currents; It produces as output: • Real and imaginary components of the three phase-phase operating currents; • Real and imaginary components of the three phase-ground operating currents; • Real and imaginary components of the polarised phase-phase voltages; • Real and imaginary components of the polarised phase-ground voltages; • Real and imaginary components of the operating phase-phase voltages; and • Real and imaginary components of the operating phase-ground voltages; The calculation of the above components depends on the configuration of the block and the polarization method selected. The currently supported polarization methods are: • Voltage, Self • Voltage, Cross (Quadrature) • Voltage, Cross (Quad L-L) • Positive Sequence • Self, ground compensated Further to this, polarizing blocks allow for settings of earth fault (𝑘0) and mutual earth fault (𝑘0𝑚) compensation parameters to be applied if these features are available in the relay model. Equations for the output quantities for each of these methods are available in the polarizing block technical reference available from the support area of the DIgSILENT website. An example of a polarizing block dialogue can be seen in Figure 39.5.1. The user can click the Assume k0 button to automatically set the zero sequence compensation factor of the polarizing block to match the calculated factor for the protected zone.

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Figure 39.5.1: Polarizing block

39.5.3.2

The starting block

The starting block is used exclusively in distance relays as a means to detect fault conditions. It can be configured to send a starting signal to protection blocks that accept such a signal. This includes Mho, Polygonal and timer blocks. The fault detection method can be based on overcurrent or impedance. Also, both phase fault and earth fault detection is supported by the block. An overcurrent starting block is shown in Figure 39.5.2.

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Figure 39.5.2: Starting block

Further information about the starting block is available in the technical reference available from the support area of the DIgSILENT website.

39.5.3.3

The distance mho block

Distance protection using mho characteristics is the traditional method of impedance based protection and was initially developed in electro-mechanical relays. Today, such characteristics are also supported by numerical protection relays primarily for compatibility with these older units but also because most protection engineers are inherently familiar with mho based protection. PowerFactory supports the following types of mho characteristics: • Impedance • Impedance (digital) • Impedance Offset • Mho • Mho Offset Mta • Mho Offset X • Mho Offset Generic • Mho Offset 2 X DIgSILENT PowerFactory 15, User Manual

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CHAPTER 39. PROTECTION • Asea RAKZB Mho Offset Details of the implementation of these characteristics in PowerFactory is explained within the technical reference available from the support area of the DIgSILENT website. From the user perspective, the type of characteristic used by the block is dependent on the type, and the user does not normally need to be concerned with its selection from the RelDismho dialogue, an example of which is shown in Figure 39.5.3.

Figure 39.5.3: Distance mho block

The user is required simply to enter the settings for the replica impedance, either in secondary or primary Ohms, and the relay angle. The block also shows the impedance characteristics of the branch that it is protecting and the effective reach of the relay in the Impedances section at the bottom of the dialogue. Note: The displayed impedance shown in blue text at the bottom of the mho block indicates the impedance of the primary protection zone. This could be a single PowerFactory line element or multiple line elements. PowerFactory automatically completes a topological search until it finds the next terminal with type “busbar", or a terminal inside a substation, or another protection device. If the “protected zone" consists of multiple parallel paths, the resulting displayed impedance is the series combination of the branches with the largest impedance of all possible branches in this search.

The distance mho block does not have a time dial internally, instead it is connected to an external timer block (refer Section 39.5.3.5) that controls the tripping time of the zone. However, the timer block associated with the particular mho zone can be conveniently accessed by clicking the Timer button. If the Timer button of a zone is greyed out, this means there is no timer block directly connected to the zone. This could be the case if the zone is designed for instantaneous tripping. 922

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39.5. SETUP AND ANALYSIS OF A DISTANCE PROTECTION SCHEME 39.5.3.4

The distance polygon block

Most modern numerical distance protection relays tend to support a so-called polygonal (also called a quadrilateral) characteristic. The benefit of such characteristics is that they allow the definition of independent resistive and reactive reaches. In particular, the ability to specify a large resistive reach is a benefit for protecting against resistive faults. Many modern relays also support other sophisticated features such as tilting reactive reaches and double directional elements to constrain the impedance characteristic to a more specific area. In fact, there is not really such a thing as a standard polygonal characteristic with each manufacturer generally using a slightly different, although often similar philosophy. Consequently, the PowerFactory polygonal block has been designed to support a range of different characteristics including: • Quadrilateral • Quadrilateral Offset • Polygonal (90°) • Polygonal (+R, +X) • Polygonal (Beta) • Siemens (R, X) • Quadrilateral (Z) • ABB (R, X) • ASEA RAZFE • Quad (Beta) • Quad Offset (Siemens 7SL32) • EPAC Quadrilateral • GE Quadrilateral (Z) Implementation details and mathematical descriptions for each of these blocks can be found in the technical reference for the polygonal block on the download area of the DIgSILENT website. As for the mho block, the user does not usually need to be concerned with the selection of the correct characteristic as this is specified by the type and would have been defined by the developer of the relay model. An example of the dialogue for the polygonal (beta) characteristic in PowerFactory is shown in Figure 39.5.4. In this case, the block is required to set the direction, the X reach, the R resistance, the X angle, the -R resistance and the Rt ratio. Like the mho block, the timer for the zone can be easily accessed through the Timer button. The Impedance section at the bottom of the dialogue shows the reach of the zone in absolute values, as well as relative to the element directly connected to the cubicle where the relay is defined. The R and X values of this element are also shown as a reference for the setup of the zone. Note: One major difference between a polygonal block and a mho block is that the polygonal block always requires a seperate directional block. There is a convenient Directional Unit button that gives access to the relevant directional unit directly from the polygonal dialogue.

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Figure 39.5.4: Distance polygon block (Polygonal (Beta))

39.5.3.5

The timer block

In distance relay models, the timer block is used to either control the tripping time of distance polygon blocks or to implement other time delays in the relay that cannot be implemented within a specific block. The block has relatively simplistic functionality for steady state simulations, but can be configured also as an output hold or a reset delay in time domain simulations. The block settings can be implemented as a time delay in seconds, or as a cycle delay. The dialogue of the timer element is shown in Figure 39.5.5. If the timer block is used to control a distance polygon, the delay can be started with a signal from the starting block.

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Figure 39.5.5: Timer block

Further technical information about the timer block can be found in the technical reference on the download area of the DIgSILENT website.

39.5.3.6

The load encroachment block

Many modern numerical distance protection relays include a so-called load encroachment feature. It is also known as a load blinder or load blocking zone. In PowerFactory four types of load encroachment characteristics are supported: • Schweitzer • Siemens • ABB • GE Most types of load encroachment can be supported by using a block with one of these characteristics. Exact implementation details for each of these blocks can be found in the technical reference for the load encroachment block on the download area of the DIgSILENT website. The user does normally not need to concern themselves with selecting the appropriate characteristic because this will have already been selected by the relay model developer. An example of a load encroachment dialogue is shown in Figure 39.5.6. In this block the user is only required to set reach and angle.

Figure 39.5.6: The GE load encroachment dialogue box

39.5.3.7

The power swing and out of step block

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CHAPTER 39. PROTECTION In PowerFactory the power swing block can be configured to trigger power swing blocking of distance zones and to trip the relay when detecting out of step conditions. One or both of theses functions can be enabled in this block. A power swing blocking condition is detected by starting a timer when the impedance trajectory crosses an outer polygonal characteristic. If a declared time (usually two - three cycles) expires before the trajectory crosses a second inner polygonal characteristic zone, then a power swing is declared and the relay issues a blocking command to distance elements in the relay. The obvious potential downside to this feature is that there is the potential to block tripping of distance zones for real faults. Fortunately, the impedance trajectory for most real faults would cross the outer and inner zones of the power swing characteristic nearly instantaneously and thus the timer would not expire and the zones would remain unblocked.

DIgSILENT

The second function of the power swing block is the detection of unstable power swings and the issuing of a trip command - this is known as out of step or loss of synchronism protection. Figure 39.5.7 shows a typical power swing blocking characteristic in red, a stable power swing impedance trajectory in green and an unstable power swing trajectory in blue. The difference between these two characteristics is that the stable swing enters and exits the impedance characteristic on the same side, whereas the unstable swing exits on the opposite side. Logic can be used to detect these different conditions and thereby issue a trip when the unstable swing is detected.

88.0 [pri.Ohm] 77.0 66.0 55.0 44.0 33.0 22.0 11.0

-143. -132. -121. -110. -99.0 -88.0 -77.0 -66.0 -55.0 -44.0 -33.0 -22.0 -11.0

11.0

22.0

33.0

44.0

55.0

66.0

77.0

88.0

[pri.Ohm]

-11.0 -22.0 -33.0 -44.0 -55.0 -66.0 -77.0 -88.0 HT\Cub_1\Power swing element

Power swing element\Polarizing Z1 Unstable Swing Stable Swing

Figure 39.5.7: Stable (green) and unstable (blue) power swings

The power swing area can be configured using internal polygonal characteristics of which the ABB and Siemens types are supported. Or alternatively, it can also be configured with external impedance elements that provide inner zone and outer zone tripping signals to the power swing block. The dialogue of the power swing element is shown in Figure 39.5.8. Note: Out of step protection can also be configured with mho elements instead of polygonal elements. 926

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39.5. SETUP AND ANALYSIS OF A DISTANCE PROTECTION SCHEME

Figure 39.5.8: Power swing element basic data page

The basic options of the power swing block are as follows: PS. No. of Phases. Typically a power swing requires the impedance trajectories of all three phases to pass through the outer and inner zones to declare an out of step condition. However, in some relays this parameter is configurable. Blocking configuration This parameter has three options: • Selecting All Zones means that a power swing blocking signal will be sent to all distance zones. • Selecting Z1 means that a power swing blocking signal will be sent to only Z1 elements. • Selecting Z1 & Z2 will send a power swing blocking signal to Z1 and Z2 distance elements only. • Selecting >= Z2 will send a blocking signal to all zones except zone 1. Out of Step Checking this box enables the out of step tripping function, unchecking it disables it. OOS No. of Crossings This field configures how many crossings of the impedance characteristic must occur before an out of step trip is issued. For example, the blue trajectory in Figure 39.5.8 is counted as one crossing. Further information for this block can be found in the technical reference on the download area of the DIgSILENT website. DIgSILENT PowerFactory 15, User Manual

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The distance directional block

The distance directional block is used by the polygonal blocks for determining the direction of the fault and also constraining the characteristic. In PowerFactory several types of distance directional blocks are supported: • Earth • Phase-Phase • 3-Phase • Multifunctional • Multifunctional (digital) • Siemens (Multi) • ABB (Multi) The user is encouraged to refer to the technical reference on the DIgSILENT support website for specific implementation details for each of these types.

39.6

The impedance plot (R-X diagram)

The impedance or R-X plot shows the impedance characteristics of distance protection relays in the R-X plane. Furthermore, the plot also shows the impedance characteristic of the network near the protection relays displayed on the diagram. The plot is also “interactive" and can be used to alter the settings of the distance zones directly, thus making it a useful tool for checking or determining optimal settings for distance relays.

39.6.1

How to create an R-X diagram

There are three different methods to create an R-X diagram in PowerFactory. You can create this plot by right clicking the cubicle, the protection device or the protection path. These methods are explained in further detail in the following sections. 1. From the cubicle: (a) Right-click a cubicle where a distance relay is installed. A context sensitive menu will appear. (b) Select the option Create R-X Plot. PowerFactory will create an R-X diagram on a new page showing the active characteristics for all relays in the selected cubicle. 2. From the relay element in the data manager (or other tabular list): (a) Right-click the relay icon. A context sensitive menu will appear. (b) Select the option Show → R-X Plot. PowerFactory will create an R-X diagram on a new page showing the active impedance characteristics of this relay. 3. From the protection path: (a) Right-click an element which belongs to a protection path. A context sensitive menu will appear. (b) Select Path. . . → R-X Plot from the context-sensitive menu. PowerFactory will create an R-X diagram on a new page showing the active characteristics for all relays in the selected path. 928

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39.6. THE IMPEDANCE PLOT (R-X DIAGRAM) In the first two methods, it is also possible to select the option Add to R-X Plot instead of Show → R-X Plot. This will open a list of previously defined R-X Plots from which any one can be selected to add the selected device characteristics to.

39.6.2

Understanding the R-X diagram

An example R-X diagram with two relays is shown in Figure 39.6.1. Shown on the plot is: • The active zone impedance characteristics for each relay. • The impedance characteristic of the network near the relay location - shown as a dashed line. • The location of other distance relays nearby - shown as solid coloured lines perpendicular to the network characteristic. • The calculated impedances for each fault loop from the polarizing blocks in each relay (shown as lightning bolts on the plot and also as values within the coloured legends). • The detected fault type as determined by the starting elements (shown in the coloured legend). Note, this is not enabled by default, see Section 39.6.3.5 for instructions how to enable this. • The tripping time of each zone (shown in the coloured legend). Note this is not enabled by default, see Section 39.6.3.5 for instructions how to enable this. • The overall tripping time of each relay (shown in the coloured legend).

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Figure 39.6.1: A R-X plot with short-circuit results and two relays

Note the information shown on the plot can be configured by altering the settings of the R-X plot. Refer to Section 39.6.3).

39.6.3

Configuring the R-X plot

There are several ways to alter the appearance of the R-X diagram. Many configuration parameters can be adjusted by right-clicking the plot and using the context sensitive menu. Alternatively, double-clicking the plot avoiding the selection of any characteristics showing on the plot will show the plot dialogue as displayed in Figure 39.6.2. The following sections explain the various ways to alter the display of the plot.

39.6.3.1

Adjusting the grid lines in the R-X diagram

To change the grid settings in the R-X diagram: 1. Right-click the R-X diagram. A context sensitive menu will appear. 2. Select Grid. The grid options dialogue will appear. 930

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39.6. THE IMPEDANCE PLOT (R-X DIAGRAM)

Figure 39.6.2: R-X plot dialogue 3. Select the Layout page. 4. To enable grid lines on the major plot divisions, check Main. 5. To enable grid lines on the minor plot divisions, check Help.

39.6.3.2

Changing the position of the R-X plot origin

Section 39.6.3.4 explains how the limits and size of the R-X diagram can be altered in detail. However, it is also possible to reposition the origin of the plot graphically. To do this: 1. Right-click the R-X diagram exactly where you would like the new origin (0,0) point of the plot to be. A context sensitive menu will appear. 2. Select Set origin. PowerFactory will reposition the origin of the plot to the place that you rightclicked.

39.6.3.3

Centering the origin of the R-X plot

To center the origin (0,0) of the plot in the center of the page: 1. Right-click the R-X diagram. A context sensitive menu will appear. 2. Select Center origin. PowerFactory will reposition the origin of the plot to the center of the page. DIgSILENT PowerFactory 15, User Manual

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R-X plot basic data page

The tabular area at the top of the dialogue shows the currently displayed relays, and the colours, line styles and line widths that are used to represent them on the plot. Each of these can be adjusted by double-clicking and selecting an alternate option. Refer to Section 17.5 for more information on configuring plots in PowerFactory. The Axis area at the bottom of the dialogue shows the settings that are currently used to scale the axes on the plot. These settings and their affect on the plot is explained further in the following section. Scale This number affects the interval between the tick marks on the x and y axis, in the units specified in the Unit field. If the Distance (see below) field remains constant, then increasing this number increases the size of the diagram and effectively zooms out on the displayed characteristics. Distance This number affects the distance in mm between each tick mark. Remember that in PowerFactory it is usual for plots and diagrams to be formatted in a standard page size (often A4). Consequently, this number has the opposite effect of the scale - when the scale field is constant increasing the distance effectively zooms into the displayed characteristics. x-Min. This field determines the left minimum point of the diagram. However, it also implicitly considers the scale. Consequently, the true minimum is determined by the product of the Scale and x-Min. For example, if the scale is 4 and x-Min is set to 2, then the minimum x axis value (resistance) displayed would be -8. y-Min. The concept for y-Min is the same as x-Min with the minimum value determined by the product of the scale and the specified minimum value. Note: The user can ask PowerFactory to adjust the scale of the R-X diagram automatically based on the set Distance. Click Characteristics to adjust the scale automatically to fit all the displayed characteristics, or click Impedances to adjust the scale to fit all displayed network impedances.

39.6.3.5

R-X plot options

The R-X plot advanced settings can be accessed by right-clicking the plot and selecting Options from the context-sensitive menu, or by pressing the Options button in the edit dialogue of the plot. The options dialogue has the following settings: Unit This option affects whether the characteristics on the plot are displayed in primary or secondary (relay) Ohm. It is also possible to select % of line which will display all characteristics in terms of a % impedance of their primary protected branch. This latter option is quite useful for visualising inspecting that the zone settings are as expected. Relays Units This option is used to display only certain types of relay characteristics. For example, it is possible to display only earth fault distance characteristics by selecting the option Ph-E. Zones This setting affects what zones are displayed. For example, to only show zone 1 characteristics, “1" should be selected. Starting This checkbox configures whether starting elements will be displayed on the diagram. Overreach zones This checkbox configures whether overreach elements will be displayed on the diagram. Power Swing This checkbox configures whether power swing elements will be displayed on the diagram. Load Encroachment This checkbox configures whether load encroachment elements will be displayed on the diagram. 932

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39.6. THE IMPEDANCE PLOT (R-X DIAGRAM) Complete shape This checkbox enables the display of the complete polygonal characteristic, when part of it would normally be invisible (and not a valid pickup region) due to the effect of the distance directional element. Enabling it also allows the selection of the line style for the displayed part of the characteristic that is not normally visible. Display This option is used to select how the calculated load-flow or short-circuit current/equivalent impedance will be displayed. The options are a short-circuit Arrow, a Cross or to Hide it completely. Colour out of service units By default out of service characteristics are invisible . However, Out of service characteristics can be shown in a different colour making them visible on the plot. Default Length for Blinder Units This options specifies the length of blinder units on the plot in secondary Ohms.

Figure 39.6.3: R-X-Plot Settings

Branch impedances page This page specifies how the branch impedance elements are displayed on the diagram: Number of Relay Locations Only the branches are shown up to the specified number of relay locations. If zero, no branches are shown at all. Branches, max. Depth Maximum number of branches shown from each relay location. If zero, no branches are shown at all. Ignore Transformers Transformer impedances are ignored when activated. Method There are two methods for determining the branch impedance. The first, Input Data, uses the entered impedance data of the branches specified in their respective types. The second method, Calculated Impedance, effectively completes a short circuit sweep similar to that described in Section 39.7.0.3 except that impedances are calculated rather than tripping times. One scenario where this method is more accurate is when modelling the protection of a section of network with multiple infeeds. Greater accuracy is achieved at the expense of calculation time. Show Branch Options Here the line style and width can be selected.

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CHAPTER 39. PROTECTION Legend page This page determines the configuration of the coloured legend visible after a short circuit or load-flow calculations for each relay on the R-X diagram. The following options are available: Show Calculated Impedances Determines whether the impedances calculated for each fault loop by the polarizing block will be displayed in the legend. Detected Fault Type Determines whether the fault type calculated by the starting element will be displayed in the legend. Tripping Time of Relay Determines if the overall tripping time of the relay will be displayed in the legend. Tripped Zones Determines if the tripping time of each zone that trips will be displayed in the legend.

39.6.4

Modifying the relay settings and branch elements from the R-X plot

From the R-X plot, the settings of the characteristics shown can be inspected and altered if required. To do this: 1. Double click the desired characteristic. The dialogue for the characteristic will appear. 2. Inspect and/or edit settings as required. 3. Click OK to update the characteristic display on the R-X diagram. Also, it is possible to directly edit or inspect the branch elements shown on the diagram. To do so: 1. Double click the desired branch. The dialogue for the branch will appear. Note that if you hover your mouse over the element and leave it steady for a few moments the name of element will appear in the balloon help. 2. Inspect or edit the branch parameters as required. 3. Click OK to return to the R-X diagram.

39.7

The time-distance plot

The time-distance plot VisPlottz shows the tripping times of the relays as a function of the short-circuit location. It is directly connected to a path definition so it can only be created if a path is already defined. A path in a single line diagram is defined by selecting a chain of two or more busbars or terminals and inter-connecting objects. The pop-up menu which opens when the selection is right-clicked will show a Path . . . option. This menu option has the following sub-options: New this option will create a new path definition Edit this option is enabled when an existing path is right-clicked. It opens a dialogue to alter the colour and direction of the path Add To this option will add the selected objects to a path definition. The end or start of the selected path must include the end or start of an existing path. 934

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39.7. THE TIME-DISTANCE PLOT Remove Partly This will remove the selected objects from a path definition, as long as the remaining path is not broken in pieces Remove This will remove the firstly found path definition of which at least one of the selected objects is a member There are a number of ways to create a time-distance diagram but it is should be noted that in each case a path must first be defined and furthermore, highlighted in the single line diagram. The elements which belong to a particular path can be highlighted by setting the colour representation of the single-line diagram to Protection tab → Other → Groupings→ Paths. To create the diagram either: • Right-click an element which is already added to a path definition. From the context sensitive menu the option Show → Time-Distance Diagram can be selected. PowerFactory will then create a new object VisPlottz showing the time-distance plot for all distance relays in the path. • Right-click a path element and select Path. . . → Time-Distance Diagram from the context sensitive menu. As above, this will create a new object VisPlottz. • Path object SetPath can be chosen in the data manager under Database ∖Projectname ∖Paths. Select the “Paths" folder and right-click the path object on the right side of the data manager. Then select Show → Time-Distance Diagram from the context sensitive menu.

39.7.0.1

Forward and reverse plots

Figure 39.7.1: A forward time-distance plot

Figure 39.7.1 illustrates a forward direction time-distance plot. The diagram shows all relay tripping times in the forward direction of the path. It is also possible to display diagrams which show in the reverse direction. There are three different options for displaying the diagrams. These are: DIgSILENT PowerFactory 15, User Manual

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39.7.0.2

The path axis

Figure 39.7.2: A path axis

The path axis in Figure 39.7.2 shows the complete path with busbar and relay locations. Busbars/Terminals are marked with a tick and the name. The coloured boxes represent relays and the left or right alignment represents their direction.

39.7.0.3

Methods of calculating tripping times

There are several methods to calculate the tripping times shown in the plot. To change the method, select the Method option in the context sensitive menu or double-click the plot to access the timedistance plot dialogue and edit the Methods option on the Relays page. The methods differ in exactness and speed. The set of possible units for the x-Axis depends on the method used. The methods are: Short-circuit sweep method The short-circuit sweep method is the most accurate method for charting the variation in relay tripping time with fault position. A routine is followed whereby short circuits are assumed to occur at numerous positions between the first and the last busbar in the path. At each short-circuit location the relay tripping times are established. The user can control the distance between simulations to ensure adequate resolution. Furthermore there is a control strategy employed within the routine to ensure that step changes in operation time are not missed. The disadvantage of this method is it’s low speed. Whenever the rebuild button of the graphics window is pressed the sweep is recalculated. The possible units for the short-circuit location are position in km, reactance in primary ohms or reactance in relay ohms. Kilometrical method This method is the fastest but can in certain circumstances be less accurate than the short-circuit sweep method. Tripping time is determined at each position where the impedance characteristic of the path intersects the relay characteristics. The impedances used for calculation are the impedances of the device. If there is more than one intersection at the same impedance the smallest tripping time is used. Although extremely useful for fast calculations in simple network scenarios, care must be taken to ensure that the results achieved are accurate. For instance, this method will not account for the starting characteristic of a distance relay and a plot may therefore be produced that does not reflect the true time current plot. The possible units for the short-circuit location are position in km or reactance, resistance and impedance, each in primary or relay ohm.

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39.7. THE TIME-DISTANCE PLOT

Figure 39.7.3: The Time-Distance plot edit dialogue

The kilometrical method is applicable only for the following paths: • Where there are no parallel branches in the path. • Where the path is fed from only one side or there is no junction on the path.

39.7.0.4

Short-circuit calculation settings

If the method for the calculation of the time-distance plot is set to Short-Circuit sweep, the short-circuit sweep command object ComShcsweep is used. The command can be accessed by the option ShcCalc... in the context menu of the plot or by the Shc-Calc... button in the Time Distance Plot edit dialogue. Some of the settings in the command are predefined by the time-distance plot. These settings are greyed out when the sweep command is accessed through the plot. The short-circuit command for the calculation is set in the sweep command. To change the short-circuit method, i.e. from IEC60909 to Complete, open the sweep command and edit the short-circuit dialogue. Note: The easiest way to recalculate the short-circuit sweep for the time-distance plot is by simply pressing the button . This is only needed when using the Short-Circuit Sweep method.

39.7.0.5

The distance axis units

There are number of possible distance axis units available depending on the method used. See the methods description for details. The short-circuit sweep method needs a relay to measure the

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CHAPTER 39. PROTECTION impedance which is named the reference relay. If there is no reference relay selected, the distance is measured from the beginning of the path. The options available for the distance axis units are: Length Distance axis is shown in km depending on the line/cable length from the reference relay. Impedance (pri.Ohm) Distance axis shows the primary system impedance from the reference relay to the remote end of the path. Reactance (pri.Ohm) Distance axis shows the primary system reactance from the reference relay to the remote end of the path. Impedance (sec.Ohm) Distance axis shows the secondary impedance from the reference relay to the remote end of the path. Reactance (sec.Ohm) Here the secondary reactance from the reference relay is measured on the secondary side.

39.7.0.6

The reference relay

The distance axis positions or impedances are calculated relative to the beginning of the path. If a reference relay is set the positions/impedances are relative to the reference relay. The sweep method always needs a reference relay. If no reference relay is set, the first relay in the diagram’s direction is taken to be the reference relay. The busbar connected to the reference relay is marked with an arrow. The reference relay is set using either the graphic or by editing the Time Distance Diagram dialogue. Changing the reference relay graphically is done by clicking with the right mouse button on the relay symbol and selecting Set reference relay in the context menu. If there is more than one relay connected to the selected busbar, PowerFactory offer a list of relays which can be used. In the dialogue of the Time Distance Relay the Reference Relay frame is located at the bottom.

39.7.0.7

Capture relays

The Capture Relays button enables the user to easily add relays in the selected path to the timedistance diagram. In order to delete a relay from the diagram, the respective line in the relay list has to be deleted.

39.7.0.8

Double-click positions

The following positions can be double-clicked for a default action: Axis Edit scale Curve Edit step of relay Relay box Edit relay(s) Path axis Edit Line Any other Open the STime ¸ DistanceTˇ edit dialogue

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39.8. DISTANCE PROTECTION COORDINATION ASSISTANT 39.7.0.9

The context sensitive menu

If the diagram is right-clicked at any position, the context sensitive menu will pop up similar to the menu described in Chapter 17: Reporting and Visualizing Results, Section 17.5.2 (Plots) for the virtual instruments. There are some additional functions available in addition to the basic VI-methods for the time-distance plot. Grid Shows the dialogue to modify the grid-lines. Edit Path Opens the dialogue of the displayed path definition (SetPath). Method Sets the method used for calculation of tripping times. x-Unit Sets the unit for the distance axis, km impedances,... Diagrams Select whether diagrams show forward, reverse or both. Consider Breaker Opening Time Report This option prints out a report for the position of the relays, their tripping time as well as all calculated impedances in the output window. Shc-Calc... Show Short-Circuit Sweep command dialogue.

39.8

Distance protection coordination assistant

PowerFactory includes a protection coordination assistant that can assist with automatically determining correct settings for distance (impedance based) protection relays. This section explains how to use this tool.

39.8.1

Distance protection coordination assistant - technical background

This section provides a brief overview of distance protection coordination. The user may wish to skip this section and move directly to the sections about configuring the tool if they are already familiar with the basic principles of distance protection coordination. A distance protection scheme works by continuously measuring the voltage and current on a protected circuit. These values can then be used to calculate an equivalent impedance. This impedance can then be compared to a “reach" setting and the basic idea is that the relay should trip if the measured impedance is less than the reach setting. On an unfaulted circuit the voltage will be high (normally tens to hundreds of thousands of volts) and the current much lower (normally tens to hundreds of Amps). Therefore, according to Ohms law, the normal load impedance is typically hundreds of Ohms. Consider now a three phase bolted fault on a transmission circuit. The voltage falls to zero at the point of the fault and the current increases in proportion to the source voltage and the impedance between the source and the fault. At the near end of the circuit where the protection relay and measuring CTs and VTs are located, the voltage will drop and the current will increase. The ratio of the voltage at the source to the fault current will be the impedance of the line to the point of the fault. Using this principle, relays can be set to protect a certain ’zone’ of a line and accurately discriminate between nearby faults and more distant faults. In practical distance protection relays so-called “polarising" voltage and current quantities are used to measure the impedance and determine whether a fault is “in zone" or “out of zone". In modern numerical DIgSILENT PowerFactory 15, User Manual

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CHAPTER 39. PROTECTION distance protection relays, often the polarised voltage quantities include a memory component that allows the relay to operate correctly for faults close to the relaying point. Further detail on this and other aspects of distance protection can be found in many reference texts and the interested user should refer to these for further information. For the purpose of coordination, a basic distance protection scheme often consists of three zones of protection: • Zone 1 that covers 80 % of the protected circuit and is usually set to instantaneous trip. • Zone 2 that covers 100 % of the protected circuit and a portion of the next adjacent circuit. Zone 2 protection must be time delayed so that discrimination can be achieved with the zone 1 protection on the adjacent circuit. A typical time delay is 400 ms. • Zone 3 protection provides backup protection for the adjacent circuit and is often set to the impedance of the protected circuit + 100 % of the adjacent circuit. It has a longer time delay than zone 2, typically 800 ms. Sometimes this zone is set to look in a reverse direction to provide backup for bus protection systems.

L3-4_ R1=1.5 Ohm X1=15.0 Ohm Z1=15.1 Ohm

SG ~

Ld-02 G02

SG ~

B02-2

4.

Ld-03 G03

L2-3_ R1=0.5 Ohm X1=5.0 Ohm Z1=5.0 Ohm

3.

Ld-01 G01

SG ~

L1-2_ R1=1.0 Ohm X1=10.0 Ohm 1. Z1=10.0 Ohm 2.

5.

B03-2

6.

B01-1

DIgSILENT

In PowerFactory , the coordination assistant automatically determines protection settings for each protection location in a user defined path. The functionality of the coordination tool is best described with reference to an example network. Consider the simplified transmission network shown in Figure 39.8.1. This network contains four busbars, three transmission lines along with associated generation and load. The locations where distance protection devices are located are indicated with a blue circle, and the direction in which they are “looking" is indicated with blue arrows. Line impedances are shown above the centre of each line.

Figure 39.8.1: Example simplified transmission system for the protection coordination example

The coordination assistant will determine the settings for three zones and an overreach zone for each 940

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39.8. DISTANCE PROTECTION COORDINATION ASSISTANT location within the protection path. In this example, there are six locations where settings will be determined, so in total the tool will determine 24 reach settings. When determining the settings for each zone of protection, there are two main options which affect how PowerFactory calculates the zone settings, Zone factors and Apply factors to. There are three methods that can be selected in Zone factors, Independent, Cumulative and Referred to Line 1. The calculation can be based on the line impedance or on the line reactance. In the latter case, the resistance settings are also determined by PowerFactory according to the entered resistive reach factors. The following sections discuss the calculations for each of three zone factor methods.

39.8.1.1

Independent method

The zone impedances are determined as follows: 𝑍𝑠1 = 𝑍𝑚1 × 𝑍𝑓 1

(39.20)

𝑍𝑠2 = 𝑍𝑚1 + 𝑍𝑚2 × 𝑍𝑓 2

(39.21)

𝑍𝑠3 = 𝑍𝑚1 + 𝑍𝑚2 + 𝑍𝑚3 × 𝑍𝑓 3

(39.22)

where 𝑍𝑠𝑛 is the impedance setting for the zone, 𝑍𝑚𝑛 is the impedance of the respective line and 𝑍𝑓 𝑛 is the entered zone factor. Note that all impedances are complex. In the case that the first stage has parallel lines (as in a double circuit) then the calculation of the reactive component is as follows: 𝑋𝑠1 = 𝑋𝑚1 × 𝑍𝑓 1

(39.23)

𝑍𝑓 2 2 = 𝑋𝑚1 + 𝑋𝑚2 × 𝑍𝑓 2

𝑋𝑠2 = 𝑋𝑚1 + 𝑋𝑚2 ×

(39.24)

𝑋𝑠3

(39.25)

The calculation of the resistive component is the same as the case where there is no parallel line in the first stage.

39.8.1.2

Cumulative method

This method comes from [20]. The zone impedances are determined as follows: 𝑍𝑠1 = 𝑍𝑚1 × 𝑍𝑓

(39.26)

𝑍𝑠2 = 𝑍𝑠1 + 𝑍𝑚2 × (𝑍𝑓 )

2

(39.27)

𝑍𝑠3 = 𝑍𝑠2 + 𝑍𝑚3 × (𝑍𝑓 )

3

(39.28)

where 𝑍𝑠𝑛 is the impedance setting for the zone, 𝑍𝑚𝑛 is the impedance of the respective line and 𝑍𝑓 is the entered zone factor. Note that all impedances are complex. In the case that the first stage has parallel lines (as in a double circuit) then the calculation of the reactive components are as follows: 𝑋𝑠1 = 𝑋𝑚1 × 𝑍𝑓 𝑍𝑓 2 = 1.1 × (𝑋𝑚1 + 𝑋𝑚2 )

(39.29)

𝑋𝑠2 = 𝑋𝑠1 + 𝑋𝑚2 ×

(39.30)

𝑋𝑠3

(39.31)

The calculation of the resistive component is the same as the case where there is no parallel line in the first stage. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 39. PROTECTION 39.8.1.3

Referred to line 1 method

In this method, all the calculated zone impedances are based the impedance of the first protected line and the entered zone factors. The zone impedance settings are calculated as follows: 𝑍𝑠1 = 𝑍𝑚1 × 𝑍𝑓 1

(39.32)

𝑍𝑠2 = 𝑍𝑚1 × 𝑍𝑓 2

(39.33)

𝑍𝑠3 = 𝑍𝑚1 × 𝑍𝑓 3

(39.34)

In general for this method, the zone factors entered should be ascending. PowerFactory will print a warning to the output window when it detects this is not the case. For this method, there is no distinction between the single and double circuit cases.

39.8.1.4

Overreach setting

The calculation of the overreach setting is identical for all three calculation methods: 𝑍𝑂𝑅 = 𝑍𝑚1 × 𝑍𝑓 𝑂𝑅

(39.35)

where 𝑍𝑓 𝑂𝑅 is the overreach factor.

39.8.1.5

Resistive reach

If the reactance method is selected, then the user can select that the resistance values are calculated according to either prospective fault resistance or prospective load resistance. For the prospective fault resistance method, the Phase-Phase resistance is calculated as follows: 𝑅𝑃 𝐻𝑃 𝐻 = 𝑅𝐿 + 𝑘𝑃 𝐻 × 𝑅𝑓

(39.36)

where 𝑅𝐿 is the calculated resistance for the zone, 𝑘𝑃 𝐻 is the Phase-Phase correction factor and 𝑅𝑓 is the prospective Fault Resistance. The Phase-Earth impedance is calculated as follows: 𝑅𝑃 𝐻𝐸 = 𝑅𝐿 + 𝑘𝐸 × 𝑅𝑓

(39.37)

where 𝑘𝐸 is the Phase-Earth correction factor. For the prospective load resistance method, first the load impedance is calculated: (︂ )︂ 𝑈𝑛𝑜𝑚 𝑅𝐿𝑑 = 𝑘𝐿 × √ 3 × 𝐼𝑛𝑜𝑚

(39.38)

Phase-Phase resistance is calculated as follows: 𝑅𝑃 𝐻𝑃 𝐻 = 𝑅𝐿𝑑 + 𝑘𝑃 𝐻

(39.39)

The Phase-Earth resistance is calculated as follows: 𝑅𝑃 𝐻𝑃 𝐻 = 𝑅𝐸 + 𝑘𝐸

39.8.2

(39.40)

Worked example of the distance protection coordination assistant

Using the example in Figure 39.8.1, and the formulas developed in Section 39.8.1, the results from the protection coordination tool can be calculated. As an example, the results for location one which is the required settings for a relay that would protect L1-2 are shown in Table 39.8.1. 942

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39.8. DISTANCE PROTECTION COORDINATION ASSISTANT Stage

X (Ω)

Rp (Ω)

Re (Ω)

Z (Ω)

𝜑

1 2 3 Overreach

8.500 14.000 25.500 12.000

0.850 1.400 2.550 1.200

0.850 1.400 2.550 1.200

8.542 14.070 25.627 12.060

84.289 84.289 84.289 84.289

Table 39.8.1: Calculated zone settings for location 1 in Figure 39.8.1 using the Impedance option of the Independent method

If using the cumulative method, the results would be as shown in Table 39.8.2. Stage

X (Ω)

Rp (Ω)

Re (Ω)

Z (Ω)

𝜑

1 2 3 Overreach

8.500 12.113 21.324 12.000

0.850 1.211 2.132 1.200

0.850 1.211 2.132 1.200

8.542 12.173 21.431 12.060

84.289 84.289 84.289 84.289

Table 39.8.2: Calculated zone settings for location 1 in Figure 39.8.1 using the Impedance option of the Cumulative method

If using the Referred to Line 1 method, the results would be according to Table 39.8.3. Stage

X (Ω)

Rp (Ω)

Re (Ω)

Z (Ω)

𝜑

1 2 3 Overreach

8.500 8.000 7.000 12.000

0.850 0.800 0.700 1.200

0.850 0.800 0.700 1.200

8.542 8.040 7.035 12.060

84.289 84.289 84.289 84.289

Table 39.8.3: Calculated zone settings for location 1 in Figure 39.8.1 using the Impedance option of the Referred to Line 1 method

Consider now the case where the first stage consists of parallel lines as shown in Figure 39.8.2. In this case, the formulas used for calculating the stage settings are different as discussed in Section 39.8.1. Consequently, for the Independent method using the Impedance method the results from the coordination assistant are as shown in Table 39.8.4.

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CHAPTER 39. PROTECTION

L3-4 R1=2.00 Ohm X1=20.00 Ohm Z1=20.10 Ohm 6.

L2-3 R1=0.50 Ohm X1=5.00 Ohm 3. Z1=5.02 Ohm 4.

Ld-3 G3

SG ~

B03

SG ~

B02

G1 Ld-1

B01

SG ~

L1-2-2 R1=1.00 Ohm X1=10.00 Ohm Z1=10.05 Ohm

5.

Ld-2 G2

L1-2-1 R1=1.00 Ohm X1=10.00 Ohm 1. Z1=10.05 Ohm 2.

Figure 39.8.2: Path with a double circuit between the first two busbars

Stage

X (Ω)

Rp (Ω)

Re (Ω)

Z (Ω)

𝜑

1 2 3 Overreach

8.500 12.000 14.000 12.000

0.850 1.400 2.550 1.200

0.850 1.400 2.550 1.200

8.542 12.081 14.230 12.060

84.289 83.346 79.677 84.289

Table 39.8.4: Calculated zone settings for location 1 in Figure 39.8.2 using the Impedance option of the Independent method

The results for the cumulative method are shown in Table 39.8.5. Stage

X (Ω)

Rp (Ω)

Re (Ω)

Z (Ω)

𝜑

1 2 3 Overreach

8.500 10.625 16.500 12.000

0.850 1.211 2.132 1.200

0.850 1.211 2.132 1.200

8.542 10.694 16.637 12.060

84.289 83.496 82.636 84.289

Table 39.8.5: Calculated zone settings for location 1 in Figure 39.8.2 using the Impedance option of the Cumulative method

If the Apply Factors to option is set to Reactance, and the fault resistance method used with Fault Resistance of 5, Factor for Ph-Ph of 0.5 and Factor for Ph-E of 1, then the results using the independent method are as shown in Table 39.8.6.

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39.8. DISTANCE PROTECTION COORDINATION ASSISTANT Stage

X (Ω)

Rp (Ω)

Re (Ω)

Z (Ω)

𝜑

1 2 3 Overreach

8.500 14.000 25.500 12.000

3.500 4.000 5.500 1.200

6.000 6.500 8.000 1.200

9.192 14.560 26.086 12.060

67.620 74.055 77.829 84.289

Table 39.8.6: Calculated zone settings for location 1 in Figure 39.8.1 using the Reactance option of the Independent method

39.8.3

Prerequisites for using the distance protection coordination tool

Before starting the distance protection coordination assistant, ensure the following: 1. A network model of the area has been completed in PowerFactory . 2. Define path(s) for the protection area(s) to be coordinated. See Section 13.8 for more information about paths. 3. Optional: If it is desired to calculate the settings for existing relays, ensure that protection devices including instrumentation transformers are added to the model.

39.8.4

How to run the distance protection coordination calculation

To run the distance protection coordination follow these steps: 1. Click the

icon on the main toolbar.

2. Select Protection. 3. Click the

icon. A dialogue for the Protection Coordination Assistant will appear.

icon and choose Select Path(s). A dialogue showing the available protection paths 4. Click the will appear. 5. Select one or more paths and click OK. 6. Optional: Choose one of the options for Protection Topology. See Section 39.8.5 for an explanation of the options. 7. Optional: Adjust options for the coordination on the Distance Protection and Advanced Options pages. 8. Click OK to run the coordination. PowerFactory will write a short status to the output window notifying for how many protection locations coordination was determined. 9. To analyse results of the coordination see Section 39.8.6.

39.8.5

Distance protection coordination options

This section explains the options in the distance protection coordination tool.

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CHAPTER 39. PROTECTION 39.8.5.1

Basic options of the protection coordination assistant

Protection Topology If According to network topology is selected the assistant will automatically determine settings for every cubicle in the protection path. If According to installed Protection devices is selected the assistant will only calculate settings for those cubicles that contain at least one relay. Results This selection control determines the result object that records the results of the protection coordination. By default this is stored within the active study case. However, it is possible to select a result object in an alternative location.

39.8.5.2

Distance Protection page

Zone Factors See Section 39.8.1 for an explanation of how this option affects the settings determination. Apply Factors to Selecting Impedance means that the reach settings will be determined based on the line impedance and resistive reach settings will also be determined automatically. Selecting Reactance means that the reach settings will be based on the line reactance. In addition, the settings for the resistive reach calculation must be entered. See Section 39.8.1 for an explanation for how these factors affect the results of the analysis. Zone Factors See Section 39.8.1 for an explanation of the effect of the zone factors.

39.8.5.3

Advanced Options page

Zone 3 This option affects the line that PowerFactory uses for calculating the impedance of the third stage. The effect of this option can be clarified by referring to Figure 39.8.3. If the first option is chosen Prefer smallest impedance at the end of line 2 then Line-3X will be used for the calculation of the zone 3 stage. Conversely, if the option Prefer largest impedance at the end of line 1 then Line-2X would be used for the zone 3 stage calculation.

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39.8. DISTANCE PROTECTION COORDINATION ASSISTANT

6.

L1-2_ R1=1.00 Ohm X1=10.00 Oh.. 1. Z1=10.05 Oh.. 2.

DIgSILENT

Line-3X R1=1.20 Ohm X1=12.00 Ohm Z1=12.06 Ohm L3-4_ R1=1.50 Ohm X1=15.00 Ohm Z1=15.07 Ohm

5.

L2-3_ R1=0.50 Oh.. X1=5.00 Oh.. Z1=5.02 Oh..

3.

4.

Ld-03 G03

B03-2

SG ~

Ld-02 G02

SG ~

Ld-01 G01

B02-2

B01-1

SG ~

Line-2X R1=0.60 Ohm X1=6.00 Ohm Z1=6.03 Ohm

Figure 39.8.3: Distance protection coordination network with additional parallel lines between bus 2 and 3 and between bus 3 and 4.

39.8.6

How to output results from the protection coordination assistant

This section explains how the results from the distance protection coordination assistant can be analysed. The graphical method of analyis using the time-distance diagram and the tabular method using the built-in report are discussed. Furthermore, there is an option to write the coordination results back to the protection relays located within the analysed path. To output results from the protection coordination assistant follow these steps: 1. Execute the protection coordination tool. See Section 39.8.4 for instructions how to do this. the icon from the protection toolbar. A dialogue for choosing the output options will 2. Click appear. 3. Check the boxes for the reports that you would like PowerFactory to produce. The types of reports are: Create Report This option produces a tabular report similar to the results displayed within Table 39.8.1. See Section 39.8.6.1 for further information on this report. Create Time-Distance-diagram This option presents a plot showing graphically the results of the protection coordination. More information about this diagram is presented in Section 39.7. Write back to Protection Devices This option automatically updates protection devices within the protection locations with settings calculated by the coordination assistant. This option should be used with caution as any existing settings will be overwritten. Consequently, it is recommended to create a Variation before enabling this option. 4. The other options in this dialogue are: DIgSILENT PowerFactory 15, User Manual

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CHAPTER 39. PROTECTION Result File Here the results that the output is based on can be selected. If it is desired to output results from a different calculation, perhaps completed in an another study case, then this is where you can select the alternative results. Output for Select All Objects to show the results for all the paths that were used by the coordination assistant. Alternatively, it is possible to output the results from a user selected set of paths by choosing the option User-Selection and appending the desired paths to the tabular list displayed.

39.8.6.1

Table reports for the protection coordination

Enabling the option Create Report when outputting the coordination results as described in Section 39.8.6, automatically generates a table report showing the results from the previously executed protection coordination. For each location in the protection path, the following results are produced: Reactance This column shows the primary Ohm reactance for each stage. Phase Resistance This column shows the primary Ohm Phase-Phase resistance for each stage. Earth Resistance This column shows the primary Ohm Phase-Earth resistance for each stage. Impedance This column shows the Phase-Phase impedance in primary Ohms for each stage. Angle This column shows the angle of the Phase-Phase impedance for each stage. Time This column shows the proposed time setting for each stage. If multiple paths were selected as part of the protection coordination, the tabular report will include a drop-down list Coordination Area that allows you to select which results are displayed in the report. icon and select either Export as HTML for HTML To output these results to Excel or to HTML click the output in your default web browser, or Export to Excel to export the results to an Excel workbook. Note: If you recalculate the protection coordination results, this report is not automatically updated you must use the option Refresh from the icon menu to update the report.

39.8.6.2

Time distance diagrams from the protection coordination

Enabling the option Create Report when outputting the coordination results as described in Section 39.8.6, automatically generates a time distance diagram showing the results from the previously completed protection coordination. One diagram will be produced for each path. An example time distance diagram for a coordination completed using the independent method is shown in Figure 39.8.4. Note that the plot display can be configured by double-clicking the diagram. For further information about time distance diagrams refer to Section 39.7.

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DIgSILENT

39.9. ACCESSING RESULTS

1.00 Stage one (location 1) setting of 8.54 Ohms

[s]

Stage three (location 1) setting of 25.63 Ohms

Stage two (location 1) setting of 14.07 Ohms

0.80

0.60

Overreach (location 1) setting of 12.06 Ohms

0.40

0.20

0.00 -0.0000

6.0299

B01-1

12.060 B02-2

B01-1

B02-2

30.150 0.00

[pri.Ohm]

24.120

18.090

24.120

[pri.Ohm]

B03-2

B01-1

B03-2 18.090

30.150

B01-1 12.060

6.0299

-0.0000

0.20

0.40

0.60

0.80 [s] 1.00 x-Axis:

Impedance B03-2 - L2-3_

B01-1 - L1-2_ B03-2 - L3-4_

B02-2 - L1-2_ B01-1 - L3-4_

B02-2 - L2-3_

Figure 39.8.4: Time distance diagram showing the result from the protection coordination using the independent method on the network shown in Figure 39.8.1

39.8.6.3

Writing results back to protection devices

If the option Write back to Protection Devices is checked, then PowerFactory will write the results from the protection coordination back to the protection devices that are located within the path. There are some important things to note about this process: • The calculation will overwrite all settings for all protection blocks for every relay in all cubicles considered by the protection coordination tool, regardless of whether they are in service or not. For example, a SEL311B relay contains three Phase Mho elements and three Phase Quadrilateral elements. If this relay was located within a cubicle considered by the coordination then all six blocks would get updated settings. • The tool does not update the angle in the mho protection blocks. Instead, it uses the existing angle in the block to adjust the impedance reach of the relay. For example if the calculated X reach is 10 Ω and the block angle is 70 ° then the impedance written to the block would be 𝑋/ sin (70) = 10.64 Ω. • Due to the potentially large number of settings changes, it is recommended to create a Variation prior to applying the settings. Subsequently, it is easy to revert to the old settings by disabling the Variation. Refer to Section 15.2 for more information about PowerFactory Variations.

39.9

Accessing results

After all protection devices have been configured and graded, it is often desirable to create reports for future reference. Aside from exporting the time-overcurrent, R-X or time-distance plots as graphical DIgSILENT PowerFactory 15, User Manual

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CHAPTER 39. PROTECTION files (see Chapter 17: Reporting and Visualizing Results, Section 17.5.10: Tools for Virtual Instruments), there are several other methods to report the relay settings.

39.9.1

Tabular protection setting report

A report command specifically for protection can be accessed by either clicking on the Output of Protection Settings icon on the Protection toolbar or alternatively via the “Output" entry in the main menu. The Output of protection settings command dialogue (ComProtreport) has three pages: • Basic Options • Common Options • Specific Options Basic Options The Basic Options page is illustrated in Figure 39.9.1:

Figure 39.9.1: Basic options page of ComProtreport dialogue

In this page the user chooses which equipment to generate reports for. First the user chooses general classes of equipment from the options below: 950

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39.9. ACCESSING RESULTS • Instrument Transformers • Overcurrent Protection • Distance Protection • Voltage Protection • Frequency Protection any combination of the above options may be selected. Each option which is selected will result in the generation of a separate tabular report. I.e. if all five options are selected, five tabular reports will be generated. In the lower section of the page the user can choose to consider all protection devices in the active grid or only a specific user defined subset. The following objects may be selected as a user defined subset: SetSelect, SetFilt, ElmNet, ElmArea, ElmZone, ElmFeeder, ElmSubstat and ElmTrfstat. Additionally a single protection device (ElmRelay, RelFuse) can also be selected. Common Options The Common Options page is illustrated in Figure 39.9.2:

Figure 39.9.2: Common options page of the ComProtreport dialogue

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CHAPTER 39. PROTECTION The decimal precision section can be used to define the number of decimal places to which results are given in the tabular reports. The precision for each unit can be defined individually. The layout options section is used to configure the layout for each report. Depending on whether they are selected, "Device, Location and Branch" will be the first three columns of the report. If the show instrument transformers option is selected, additional columns will be added to the overcurrent, distance, voltage and frequency protection reports showing details of the instrument transformers. If the Report settable blocks only option is selected, blocks which have no user configurable settings will not be displayed in the report. If the Arrange stages vertically option is selected, additional rows will be added to the report for each protection stage, rather than including additional stages as additional columns. If the Show ANSI code option is selected, each stage column will include the relevant ANSI code as defined by IEEE (ANSI) C37-2. Specific Options The Specific Options page is illustrated in Figure 39.9.3:

Figure 39.9.3: Specific options page of the ComProtreport dialogue

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39.9. ACCESSING RESULTS settings should be displayed in primary units, secondary units, or per unit. Any combination of the 3 options is possible. This page is also used to limit the report for each type of protection to a specified number of phase and earth fault protection stages. One the ComProtreport dialogue has been configured it can be executed. The Tabular Report An example of a tabular report generated when the ComProtreport dialogue is executed is illustrated in Figure 39.9.4:

Figure 39.9.4: ComProtreport Tabular report

Relay models (and sometimes stages depending on the setting detailed above) are listed vertically while settings are listed horizontally. The downward pointing triangular icon at the top of the page can be used to export the report either as HTML format or in excel spreadsheet format. It is also possible to interact with the data within the report. For instance, if you double click on a particular stage (or right click and select edit it is possible to edit the settings dialogue for that stage. Data within this table may also be copied and pasted if required, with or without column headers.

39.9.2

Results in single line graphic

The names of the relays or the tripping times may be made visible in the single line graphic by selecting the following options in the main menu. • Output - Results for Edge Elements - Relays • Output - Results for Edge Elements - Relay Tripping Times DIgSILENT PowerFactory 15, User Manual

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CHAPTER 39. PROTECTION The first option (Relays), which is always available, will show the names of the relays in all cubicles. The second option will show the tripping times of the relays after a load-flow or short-circuit calculation has been carried out. If a relay does not trip, then a tripping time of 9999.99 s is shown. It is also possible to colour the single line graphic depending on the tripping time of the protective devices installed. This feature can be activated by clicking the diagram colouring button from the local graphics window icon bar, then selecting: the protection tab → 3. Others→ Results→ Fault clearing time.

39.10

Short circuit trace

The Short circuit trace is a tool based on the complete short circuit calculation method that allows the user to examine the performance of a protection scheme in response to a fault or combination of faults; where the response is examined in time steps and where at each time step, the switching outcomes of the previous time step and the subsequent effect on the flow of fault current, is taken into consideration. Consider a network as illustrated in Figure 39.10.1:

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39.10. SHORT CIRCUIT TRACE

Figure 39.10.1: Short circuit trace example

Suppose that for a particular fault at bus 4, the relay controlling circuit breaker 1 trips significantly faster than the relays controlling circuit breakers 2 and 3. Once circuit breaker 1 trips, the fault is not cleared but the fault current is reduced, since the contribution from the external grid is removed. To clear the fault completely, circuit breaker 2 or circuit breaker 3 must trip. Due to the dynamic variation in the fault current, the tripping times of the two circuit breakers are not immediately obvious. Ideally a dynamic simulation method should be used to accurately calculate the respective tripping times of the two circuit breakers. However, a dynamic simulation is not always practicable and where the user is willing to accept a reduced level of accuracy in exchange for a faster, simpler calculation result, then the Short circuit trace should be considered. Consider again the network illustrated in Figure 39.10.1 with a fault occurring at bus 4, all relays are overcurrent relays with the relay controlling circuit breaker 1 having a significantly faster tripping time than the other 2 relays. The Short Circuit Trace calculation proceeds as follows.

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CHAPTER 39. PROTECTION • Time Step 1 (𝑡 = 0): The fault occurs at bus 4. Fault current flows from both synchronous generators according to the complete short circuit method of calculation. The relay controlling circuit breaker 3 sees the fault current from both sources. The relays controlling circuit breakers 1 and 2 see only the fault current from the sources present in their particular branch of the network. The tripping time of each of the relays can be evaluated based on the respective magnitudes of the current components seen by the relays and with reference to each of the relay’s tripping characteristics. • Time Step 2 (𝑡 = 0 + 𝑡1): According to the tripping times calculated at Time Step 1 it is established that the relay controlling circuit breaker 1 will trip first in time 𝑡1. Therefore at stage 2 circuit breaker 1 is opened and a the complete short circuit method calculation is once again carried out for a fault at bus 4. This time, the current seen by circuit breaker 3 only includes contribution from the generator and not from the external grid. The tripping times of the relays are reevaluated based on the new current distribution. The effects of the Time Step 1 current distributions are ignored. For the purposes of this example it is assumed that circuit breaker 2 is established to be the next quickest to operate. • Time Step 3 (𝑡 = 0 + 𝑡2): According to the tripping times calculated at Time Step 2 it is established that the relay controlling breaker 2 is the next to trip and trips in time 𝑡2. Since the fault is now isolated from all connected sources, fault current no longer flows and the short circuit trace calculation is complete. From the above, a sequence of operation for the protection scheme is established and specific protection operating times are calculated, taking account of the variation in network topology that occurs during the ongoing response of a protection scheme to a fault situation. The following subsection describes the handling of the Short Circuit Trace function.

39.10.1

Short Circuit Trace Handling

A command specifically for the Short Circuit Trace feature can be accessed by clicking on the Start Short-Circuit Trace icon on the Protection toolbar. The Short-Circuit Trace command dialogue (ComShctrace) has one only one page called Basic Options Basic Options The Basic Options page is illustrated in Figure 39.10.2:

Figure 39.10.2: Basic options page of the ComShctrace dialogue

A link to the short circuit command (ComShc) to be used for the calculation is automatically generated. 956

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39.11. BUILDING A BASIC OVERCURRENT RELAY MODEL This command is described in detail in the Chapter 22. Please note that for the Short Circuit Trace function, some options are fixed. For instance, only the complete short circuit method may be selected. The Short-Circuits part of the page is used to define the short circuit events to be applied at the beginning of the calculation. The following kinds of events may be specified. • Intercircuit Fault Events (EvtShcll) • Outage Events (EvtOutage) • Short-Circuit Events (EvtShc) • Switch Events (EvtSwitch) Once the simulation is ready to begin press the execute button. At this point the simulation is initialised and the short circuit events specified in the Basic Options page are applied to the network. The user can advance through the simulation time step by time step or to the end of the simulation by clicking on the relevant icons on the Protection toolbar. Further there is an additional icon to stop the simulation at any time. The icons are illustrated in Figure 39.10.3.

Figure 39.10.3: Short Circuit trace icons

39.11

Building a basic overcurrent relay model

Some advanced users may need to build their own relay models. This section will outline the procedure for building a basic overcurrent relay model. 1. Create a new block definition for the relay frame • Select file → New→ Block Diagram / Frame... • A dialogue as illustrated in figure 39.11.1 will appear.

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Figure 39.11.1: BlkDef basic data dialogue – – – –

Give the relay frame an appropriate name. Select Level to Level 2: Level 1 + sort parameter user defined. Select classification to linear. Click ok. This creates a block definition object within the User Defined Models section of the project library.

2. Construct the relay frame. • Select the slot icon from the drawing toolbox located on the right side of the screen and place 6 slots within the block definitions arranged as illustrated in figure 39.11.2 below.

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39.11. BUILDING A BASIC OVERCURRENT RELAY MODEL

Figure 39.11.2: Arrangement of slots 3. Configure the BlkSlot dialogue for slot A. • Slot A will be configured to be a CT slot. Double click on the slot symbol and the BlkSlot dialogue will appear. • Enter an appropriate name for the slot eg. CT 3ph. • Enter the class name as StaCt*. • Ensure that only the box linear is checked in the classification field. • Enter the following output signals under the variables field: I2r_A; I2i_A, I2r_B; I2i_B, I2r_C; I2i_C. These signals will represent real and imaginary secondary currents for phases A, B and C. • The way in which the signal list above is defined influences the way the signals are represented in the relay frame. Signals can be grouped together and represented by a common terminal by separating the signals to be grouped with a semicolon. Where a group of signals or a single signal is to be given it’s own terminal representation in the relay frame then the signal or group of signals should be distinguishing from any other signals by separation with a comma. • The configured dialogue is illustrated in figure 39.11.3. • Once configured, click ok. The CT slot should now be marked with three terminals, one for each phase.

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Figure 39.11.3: CT BlkSlot dialogue 4. Configure the BlkSlot dialogue for slot B. • Slot B will be configured to be a Measurement slot. Double click on the slot symbol and the BlkSlot dialogue will appear. • Enter an appropriate name for the slot eg. Measurement. • Enter the class name as RelMeasure*. • In the classification field, ensure that only the boxes linear and Automatic, model will be created are checked • Enter the following output signals under the variables field: I_A, I_B, I_C. These represent RMS values of current for each phase. • Enter the following input signals under the variables field: wIr_A; wIi_A, wIr_B; wIi_B, wIr_C; wIi_C. These are real and imaginary current signals supplied by the CT block. • The configured dialogue is illustrated in figure 39.11.4. • Once configured click ok.

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Figure 39.11.4: Measurement BlkSlot dialogue 5. Configure the BlkSlot dialogues for slots C, D and E. • Slots C,D and E will be configured to be time overcurrent blocks with each one representing a different phase. Double click on the slot C symbol and the BlkSlot dialogue will appear. • Enter an appropriate name for the slot eg. TOC phase A. • Enter the class name as RelToc*. • In the classification field, ensure that only the boxes linear and Automatic, model will be createdŠ are checked • Enter the following output signals under the variables field: yout. • Enter the following input signals under the variables field: Iabs. This represents the RMS current signal for phase A supplied by the measurement block. • The configured dialogue is illustrated in figure 39.11.5. • Once configured click ok. • Repeat the steps above for slot D and E. Name these slots TOC phase B and TOC phase C.

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Figure 39.11.5: TOC BlkSlot dialogue 6. Configure the BlkSlot dialogue for slot F. • Slot F will be configured to be a Logic slot. Double click on the slot symbol and the BlkSlot dialogue will appear. • Enter an appropriate name for the slot eg. Logic. • Enter the class name as RelLogic*. • In the classification field, ensure that only the boxes linear and Automatic, model will be created are checked • Enter the following output signals under the variables field: yout. • Enter the following input signals under the variables field: y1, y2, y3. • The configured dialogue is illustrated in figure 39.11.6. • Once configured click ok.

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Figure 39.11.6: Logic BlkSlot dialogue All block dialogues should now be configured. 7. Connect the blocks together using signals. • Select the signal icon from the drawing toolbox located on the right side of the screen. • Connect blocks by clicking on the output terminal of the first block then by clicking on the input terminal of the receiving block. If a route for the signal is required which is not direct, intermediate clicks may be used. • If a signal is intended to be passed outside of the model then a signal should be terminated on the box which surrounds the frame. In this instance the output from the logic block will be passed outside of the model. • Connect the blocks in the frame as illustrated in figure 39.11.7.

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Figure 39.11.7: Signal route definition 8. Rebuild the block definition • Press the rebuild button on the local graphics window icon bar. Rebuilding the model will capture all the internal signals (signals defined between slots) and external signals (signals passed outside of the model) within the BlkDef model dialogue. This concludes definition of the relay frame. The next step is to define a relay type. 9. Create a relay type object • Within the data manager go to the Equipment Type library folder in the project library and select the new object icon. • In the dialogue which appears select Special Type → Relay Type (TypRelay) as illustrated in figure 39.11.8.

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Figure 39.11.8: Creating a new relay type • In the TypRelay dialogue that appears give the relay type an appropriate name. • In the relay definition field select the relay frame constructed earlier from the User Defined Models section of the project library. • Select the category as overcurrent relay. 10. Define the CT type • The CT type can be selected by double clicking in the type column associated with the CT row. • The desired CT should be selected from the data manager. 11. Define the measurement type • The measurement type can be selected by double clicking in the type column associated with the measurement row. For this example select the following options: • Select Type to 3ph RMS currents • Select nominal current to discrete with a value of 5. • Select measuring time to 0.001 • Ensure no check boxes are selected. 12. Define the TOC types • The TOC types can be selected by double clicking in the type column associated with the rows of each of the three TOC slots. For this example select the following options for each TOC type: • Select IEC symbol I>t and Ansi symbol 51. • Select type to phase A, B or C current depending on the slot. • Select directional to none. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 39. PROTECTION • Select current range to range type: stepped, minimum: 0.5, maximum: 2 and step size: 0.25. • Check the characteristic includes pickup time box and set pickup time: 0.01s, Reset time: 0.04s and Reset Characteristic Configuration: Disabled. • Select an existing relay characteristic from another relay or create a new relay characteristic by creating a TypChatoc object. • On the Total clear curve tab ensure no boxes are checked. • On the blocking page, select consider blocking to disabled. • Select release blocking time range to range type: stepped, minimum: 0 maximum: 10000 and step size: 0.01. 13. Define the Logic types • The Logic type can be selected by double clicking in the type column associated with the logic row. • Select Breaker event to open. • Select number of inputs to 4. • Select number of block inputs to 4. • Select a logical OR operation. This concludes definition of the relay type. To use the relay type a relay must be created within the network. The relay type can then be selected, and the relay element parameters defined.

39.12

Appendix - other commonly used relay blocks

This section covers some of the other protection block not so far covered in the discussion throughout the chapter so far.

39.12.1

The frequency measurement block

The frequency measurement unit is used to calculate the electrical frequency for the given Measured Voltage. The Nominal Voltage is needed for per unit calculations. The Frequency Measurement Time defines the time used for calculating the frequency gradient.

Figure 39.12.1: Frequency measurement block

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39.12.2

The frequency block

The frequency block either trips on an absolute under-frequency (in Hz), or on a frequency gradient (in Hz/s). Which condition is used depends on the selected type. The type also defines the reset time, during which the defined frequency conditions must be present again for the relay to reset. The time delay set in the relay element defines the time during which the defined frequency condition must be violated for the relay to trip. See Figure 39.12.2.

Figure 39.12.2: Frequency block

39.12.3

The under-/overvoltage block

The under-/overvoltage relay type may define the block to trip on either • One of the three phase line to line voltages • One particular line to line voltage • The ground voltage 𝑈0 . • The positive sequence voltage 𝑈1 • The negative sequence voltage 𝑈2 The relay element allows only for setting of the pickup voltage and the time delay. See Figure 39.12.3.

Figure 39.12.3: Under-/Overvoltage block

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Chapter 40

Network Reduction 40.1

Introduction

This chapter explains how to use the PowerFactory Network Reduction tool. A typical application of Network Reduction is when a network that is part of or adjacent to a much larger network must be analyzed, but cannot be studied independently of the larger network. In such cases, one option is to model both networks in detail for calculation purposes. However, there might be situations when it is not desirable to do studies with the complete model. For example, when the calculation times would increase significantly or when the data of the neighbouring network is confidential and cannot be published. In these cases, it is common practice to provide a simplified representation of the neighbouring network that contains only the interface nodes (connection points). These can then be connected by equivalent impedances and voltage sources, so that the short circuit and load-flow response within the kept (non reduced) system is the same as when the detailed model is used. PowerFactory Šs Network Reduction algorithm produces an equivalent representation of the reduced part of the network and calculates its parameters. This equivalent representation is valid for both load flow and short-circuit calculations, including asymmetrical faults such as single-phase faults. The chapter is separated into five parts. Firstly, the technical background of the PowerFactory Network Reduction algorithm is explained. Section 40.3 discusses the steps needed to run a Network Reduction and Section 40.4 explains in detail each of the options of the PowerFactory Network Reduction tool. The penultimate part, Section 40.5, presents a simple example and the final section provides some tips and tricks to consider when working with the Network Reduction tool.

40.2

Technical Background

Some additional technical background on the Network Reduction tool is provided in the following sections.

40.2.1

Network Reduction for Load Flow

Network reduction for load flow is an algorithm based on sensitivity matrices. The basic idea is that the sensitivities of the equivalent grid, measured at the connection points in the kept grid, must be equal to the sensitivities of the grid that has been reduced. This means that for a given (virtual) set of ∆P and ∆Q injections in the branches, from the kept grid to the grid to be reduced, the resulting ∆u and ∆𝜙 DIgSILENT PowerFactory 15, User Manual

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CHAPTER 40. NETWORK REDUCTION (voltage magnitude and voltage phase angle variations) in the boundary nodes must be the same for the equivalent grid as those that would have been obtained for the original grid (within a user defined tolerance).

40.2.2

Network Reduction for Short-Circuit

Network reduction for short-circuit is an algorithm based on nodal impedance / nodal admittance matrices. The basic idea is that the impedance matrix of the equivalent grid, measured at the connection points in the kept grid, must be equal to the impedance matrix of the grid to be reduced (for the rows and columns that correspond to the boundary nodes). This means that for a given (virtual) additional ∆I injection (variation of current phasor) in the boundary branches, from the kept grid to the grid to be reduced, the resulting ∆u (variations of voltage phasor) in the boundary nodes must be the same for the equivalent grid, as those that would have been obtained for the original grid (within a user defined tolerance). This must be valid for positive sequence, negative sequence, and zero sequence cases, if these are to be considered in the calculation (unbalanced short-circuit equivalent).

40.3

How to Complete a Network Reduction

This section explains the process for running a Network Reduction. There are several steps that you must complete to successfully reduce a network: 1. Create a boundary and define the interior and exterior regions. 2. Create a backup of the project intended for reduction (optional). 3. Activate the additional tools toolbar and configure the Network Reduction Tool options. 4. Run the Network Reduction Tool. You must define a boundary before you can proceed further with the Network Reduction. This process is described in detail in Chapter 13 Grouping Objects, Section 13.3 (Boundaries). However, to summarize, the boundary divides the network into two regions, the area to be reduced which is referred to as the interior region and the area to be kept which is referred to as the exterior region. The following section describes the process of backing up the project, running the Network Reduction tool using the default options and describes the expected output of a successful network reduction. For more information about the options available within the Network Reduction tool, see Section 40.4: Network Reduction Command.

40.3.1

How to Backup the Project (optional)

By default, the Network Reduction tool keeps all the original network data and the modifications needed to reduce the network are stored within a new expansion stage that is part of a new variation. It will only destroy the original data if the associated option within the command is configured for this (see Section 40.4.2: Outputs). However, if you want extra security to guarantee against data loss, in case for instance you accidently select the option to modify the original network, then you should make a backup copy of the project before completing the Network Reduction. There are three possible ways to do this: • make a copy of the whole project and paste/store it with a name different to that of the original project; or 970

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40.3. HOW TO COMPLETE A NETWORK REDUCTION • export the project as a *.dz- or *.pfd file (for information about exporting data please refer to Section 8.1.5: Exporting and Importing of Projects); or • activate the project and create a Version of the project. For information about Versions please refer to Section 18.2 (Project Versions).

40.3.2

How to run the Network Reduction tool

This sub-section describes the procedure you must follow to run the Network Reduction using the default options. Proceed as follows: 1. Activate the base Study Case for the project you wish to reduce. 2. Define a boundary that splits the grid into the part to be reduced (interior region), and the part to be kept (exterior region). See Section 13.3 (Boundaries) for the procedure. 3. Open the boundary object and use the Check Split button in the ElmBoundary dialogue to check that the boundary correctly splits the network into two regions. See Section 13.3 (Boundaries) for more information about boundaries. 4. Select the Change Toolbox button

from the main toolbar. This is illustrated in Figure 40.3.1.

5. Press the Network Reduction icon from the Additional Tools bar (Figure 40.3.1). This opens the dialogue for Network Reduction Command (ComRed). 6. Select the boundary you previously defined using the selection control

.

7. Optional: If you wish to modify the settings of the command, do so in this dialogue. The settings and options are explained in Section 40.4 (Network Reduction Command). However, the default options are recommended, unless you have a specific reason for changing them. 8. Press the Execute button to start the reduction procedure.

Figure 40.3.1: The Network Reduction Button in the Additional Tools Icon Bar

40.3.3

Expected Output of the Network Reduction

This sub-section describes the expected output of the network reduction tool after successfully executing it. The output varies depending on whether the reduced project was created in V13.2 or earlier

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CHAPTER 40. NETWORK REDUCTION and contains system stages, or if it was created in V14.0 or higher. Both output scenarios are explained in the following sections. Also, the additional objects that the Network Reduction tool creates are explained. Changes to the network model for projects created in V14.0 or higher The default behaviour of the Network Reduction command is to create a Variation containing a single Expansion Stage called ’Reduction Stage’. For more information see Chapter 15: Network Variations and Expansion Stages. The Variation will be named automatically according to the reduction options selected in the Basic Options page of the Network Reduction command. For example, for the default options the Variation will be named Equ-LF [EW] - Shc[sym] @ Boundary. Figure 40.3.2 shows an example of a network data model after a successful Network Reduction.

Figure 40.3.2: Project Data tree showing the network model after a successful Network Reduction using the default options.

The Network Reduction tool also creates a new Study Case with a name that matches the new Variation name. To return to your original network, all you need to do is activate the original study case that you used to initiate the Network Reduction. Note: The Variation and Study Case created by the Network Reduction tool are automatically activated when the tool is run. To return to your original model you need to reactivate the ’base’ Study Case.

Changes to the network model for projects created in V13.2 or lower For projects imported from V13.2, if they contain System Stage(s) (superseded by Variations in V14.0), then the Network Reduction does not create a Variation in the project. Instead, a system stage is created within each active grid. Therefore, if there are ’n’ active grids when the Network Reduction process is initiated, there will be ’n’ System Stages created. The naming convention for the System Stage(s) is the same as the naming convention for the Variations described above. The new System Stage(s) will be automatically activated in the created study case. If one or more single line graphic diagrams were in the System Stage(s) within the original grid, these 972

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40.4. NETWORK REDUCTION COMMAND graphics will also be kept in the new System Stage(s) within the combined (partly kept and partly reduced) grid. The first time that the new study case is activated (automatically, at the end of Network Reduction procedure), the graphics will be displayed. The elements contained in the part of the grid which was reduced (if any of them were previously shown), will appear grey in colour, as ’ghost’ elements. Deactivating and re-activating the project will make them disappear permanently (they are graphic elements only, and have no corresponding elements in the database in the new System Stage(s)). New objects added by the Network Reduction command Depending on the network configuration and the options chosen within the Network Reduction command, during the Network Reduction process some new objects might be created. There are two possible new object types: • AC Voltage Source (ElmVac)

; and

• Common Impedance (ElmZpu) By default, there will be one voltage source created for every boundary node and one common impedance between every pair of boundary nodes (unless the calculated mutual impedance is greater than the user-defined threshold described in Section 40.4.3). These objects are stored in the database but are not automatically drawn on the single line graphic. If you need to see these objects on the single line diagram, you must add them manually using the PowerFactory tool Draw Existing Net Elements, which is explained in Section 9.6 (Drawing Diagrams with Existing Network Elements).

40.4

Network Reduction Command

In this section, the Network Reduction command options are explained.

40.4.1

Basic Options

This section describes the options on the Basic Options page of the Network Reduction command as shown in Figure 40.4.1.

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Figure 40.4.1: Network Reduction Command (ComRed) Basic Options

Boundary This selection control refers to the boundary that defines the part of the grid that shall be reduced by the reduction tool. Note, the project Boundaries folder might contain many boundaries, but you must select only one boundary from this folder. This selected boundary must separate the original grid into two parts, the part that shall be reduced (interior region) and the part that shall be kept (exterior region). For more information about boundaries, please refer to Section 13.3 (Boundaries). Load Flow Calculate load flow equivalent If this option is enabled, the load flow equivalent model will be created by the reduction tool. This option is enabled by default. Equivalent Model for Power Injection The load flow equivalent is composed of mutual impedances between boundary nodes and power injections (and shunt impedances) at boundary nodes. The power injection can be represented by different models. For the load flow equivalent there are three options (models) available: • Load Equivalent: a load demand. • Ward Equivalent: an AC voltage source which is configured as a Ward Equivalent. • Extended Ward Equivalent: an AC voltage source which is configured as an Extended Ward Equivalent. Short-Circuit Calculate short-circuit equivalent If this option is enabled, the short-circuit equivalent model will be created by the Network Reduction tool. Currently, only the complete short-circuit calculation method is supported. Asymmetrical Representation This option is used to specify whether an unbalanced shortcircuit equivalent will be created. If this option is disabled, only a balanced short-circuit equivalent will be created, valid for the calculation of 3-phase short-circuits. If this option is enabled, an 974

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40.4. NETWORK REDUCTION COMMAND unbalanced short-circuit equivalent is created, valid for the calculation of single-phase and other unsymmetrical short-circuits. This means the network representation must include zero sequence and negative sequence parameters, otherwise the unbalanced calculation cannot be done.

40.4.2

Outputs

The section describes the options available on the Outputs page of the Network Reduction command as shown in Figure 40.4.2. These options define how the Network Reduction command modifies the network model.

Figure 40.4.2: Network Reduction Command - Outputs

Calculation of Parameters Only The equivalent parameters are calculated and reported to the output window. If this option is selected then the Network Reduction command does not modify the network model. Create a new Variation for Reduced Network (Default) The equivalent parameters are calculated and a Variation will be automatically created to store the reduced network model. If the project already includes System Stage(s) (from PowerFactory version 13.2 or earlier versions) then System Stage(s) will be created instead of a Variation. Reduce Network without Creating a New Variation The Network Reduction command will directly modify the main network model if this options is selected. Therefore, this option will destroy data by deleting the ’interior’ region of the selected boundary, and replacing it with its reduced model, so this option should be used with care. To avoid losing the original grid data, backup the project as described in Section 40.3.1 (How to Backup the Project (optional)).

40.4.3

Advanced Options

This section describes the Advanced Options for the Network Reduction command as shown in Figure 40.4.3.

Figure 40.4.3: Network Reduction Command - Advanced Options

Mutual Impedance (Ignore above) As part of the Network Reduction process equivalent branches (represented using Common Impedance elements) will be created between the boundary nodes, DIgSILENT PowerFactory 15, User Manual

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CHAPTER 40. NETWORK REDUCTION to maintain the power-flow relationship between them. If such branches have a calculated impedance larger than this parameter they will be ignored (not added to the network model). By default, the number of these branches created will be N*(N-1)/2, where N is the number of boundary nodes. A boundary node is defined for each boundary cubicle. Therefore, the number of created branches can be very high. Normally many of these equivalent branches have a very large impedance value, so their associated power flows are negligible and the branch can be ignored. The default value for this parameter is 1000 p.u (based on 100 MVA). Calculate Equivalent Parameters at All Frequencies This option enables the calculation of frequency-related parameters. By default, the short-circuit equivalent parameters are calculated at all frequencies relevant to short-circuit analysis (equivalent frequencies for calculating the d.c. component of the short-circuit current): • 𝑓 = 𝑓𝑛 • 𝑓 /𝑓𝑛 = 0.4 • 𝑓 /𝑓𝑛 = 0.27 • 𝑓 /𝑓𝑛 = 0.15 • 𝑓 /𝑓𝑛 = 0.092 • 𝑓 /𝑓𝑛 = 0.055 𝑓𝑛 is the nominal frequency of the grid (usually 50 Hz or 60 Hz). If only transient and sub-transient short-circuit currents are important in the reduced network, the calculation of frequency-related parameters can be skipped by unchecking this option.

40.5

Network Reduction Example

This section presents a Network Reduction example using a small transmission network feeding a distribution system from bus 5 and bus 6 as shown in Figure 40.5.1. The distribution system is represented by Load A and Load B and the corresponding two transformers. As a user you would like to study the distribution system in detail but are not concerned with the detailed power flow within the transmission system. Therefore, the Network Reduction tool can be used to create a equivalent model for the transmission system. The interior region (the area that shall be reduced) is shown shaded in grey, whereas the non-shaded area is the exterior region that shall be kept. The procedure for completing the Network Reduction according to these parameters is as follows (you can repeat this example yourself using the nine bus system within the PowerFactory Examples - the network used in the example is slightly modified from this):

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40.5. NETWORK REDUCTION EXAMPLE

Figure 40.5.1: Example System with Original Network

1. Select cubicles that will be used to define the boundary. These are highlighted in Figure 40.5.2. (Use the freeze mode to make selection of the cubicles easier.)

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Figure 40.5.2: Cubicles used for the boundary definition. 2. Right-click one of the selected cubicles and choose the option Define → Boundary ... The boundary dialogue appears. 3. Alter the boundary cubicle orientations so that the Interior region is correctly defined. The cubicle orientation for the T4 and T5 cubicles should be set to Busbar. This means that the boundary interior is defined by looking back at the bus from these cubicles. The orientation for the Line 1 and Line 6 cubicles remains on Branch (looking into the branch). 4. Open the Network Reduction command dialogue and select the boundary defined in steps 1-3 using the selection control. 5. Press Execute. The Network Reduction tool will reduce the system. 6. Optional: draw in the three new common impedance elements and three equivalent ward voltage source objects using the Draw Existing Net Elements tool. The result of the Network Reduction is shown in Figure 40.5.3. A load flow calculation or a short-circuit calculation in the reduced network gives the same results for the distribution network as for the original (non-reduced) network.

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40.6. TIPS FOR USING THE NETWORK REDUCTION TOOL

Figure 40.5.3: Example System with Reduced Network

40.6

Tips for using the Network Reduction Tool

This section presents some tips for using the Network Reduction tool and some solutions to common problems encountered by users.

40.6.1

Station Controller Busbar is Reduced

Sometimes a interior region might be defined such that it contains the reference bus of a station controller. The generators belonging to this station controller are in the exterior region. During the reduction process the reference bus will be reduced (removed) from the model, yet the station controller and generators will remain part of the new system. In such a situation, attempting to run a load-flow after the reduction will fail with an error message similar to that shown in Figure 40.6.1.

Figure 40.6.1: Error message showing a station controller error

There are two possible solutions to this problem: DIgSILENT PowerFactory 15, User Manual

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CHAPTER 40. NETWORK REDUCTION • Modify the boundary definition slightly such that the station controller bus is excluded from the exterior region; or • Set the station controller out of service and the generators to local PV mode.

40.6.2

Network Reduction doesn’t Reduce Isolated Areas

By default, the boundary definition search stops when encountering an open breaker. This means that isolated areas can sometimes be excluded from the interior region and therefore are not reduced by the Network Reduction tool. The solution to this problem is to disable the boundary flag Topological search: Stop at open breakers. This option is enabled by default in all boundary definitions. It is recommended to disable it before attempting a Network Reduction. A related problem occurs with the project setting (Edit → Project→ Project Settings→ Advanced Calculation Parameters) Automatic Out of Service Detection. It is recommended that this option is disabled before attempting a Network Reduction. However, it is disabled by default, so if you have not made changes to the default project settings you should not need to make any changes to this setting.

40.6.3

The Reference Machine is not Reduced

The Network Reduction tool will not reduce a reference machine defined within the interior region. It also leaves all network components that are topologically one bus removed from the reference machine (and of non-zero impedance). For example, if the reference machine is a typical synchronous machine connected to the HV system through a step up transformer, then the reduction tool will leave the synchronous machine, the LV bus, the step up transformer and the HV bus within the reduced network. It is recommended that the reference machine is found within the exterior region before attempting a Network Reduction. The reference machine can be identified by checking the output window following a successful load-flow calculation as illustrated in Figure 40.6.2.

Figure 40.6.2: Output window showing the load-flow command output and the indication of the reference machine

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Chapter 41

State Estimation 41.1

Introduction

The State Estimator (SE) function of PowerFactory provides consistent load flow results for an entire power system, based on real time measurements, manually entered data and the network model. Before any further analysis, such as contingency analysis, security checks etc. can be carried out, the present state of a power system must be estimated from available measurements. The measurement types that are processed by the PowerFactory State Estimator are: • Active Power Branch Flow • Reactive Power Branch Flow • Branch Current (Magnitude) • Bus Bar Voltage (Magnitude) • Breaker Status • Transformer Tap Position Unfortunately, these measurements are usually noisy and some data might even be totally wrong. On the other hand, there are usually more data available than absolutely necessary and it is possible to profit by redundant measurements for improving the accuracy of the estimated network state. The states that can be estimated by the State Estimator on the base of the given measurements vary for different elements in the network: • Loads – Active Power, and/or – Reactive Power, or – Scaling Factor, as an alternative • Synchronous Machines – Active Power, and/or – Reactive Power • Asynchronous Machines – Active Power DIgSILENT PowerFactory 15, User Manual

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41.2

Objective Function

The objective of a state estimator is to assess the generator and load injections, and the tap positions in a way that the resulting load flow result matches as close as possible with the measured branch flows and bus bar voltages. Mathematically, this can be expressed with a weighted square sum of all deviations between calculated (calVal) and measured (meaVal) branch flows and bus bar voltages:

𝑓 (⃗𝑥) =

𝑛 ∑︁

𝑤𝑖 · |𝑐𝑎𝑙𝑉 𝑎𝑙𝑖 (⃗𝑥) − 𝑚𝑒𝑎𝑉 𝑎𝑙𝑖 |2

(41.1)

𝑖=1

The state vector ⃗𝑥 contains all voltage magnitudes, voltage angles and also all variables to be estimated, such as active and reactive power injections at all bus bars. Because more accurate measurements should have a higher influence to the final results than less accurate measurements, every measurement error is weighted with a weighting factor wi to the standard deviation of the corresponding measurement device (+transmission channels, etc.). In this setting, the goal of a state estimator is to minimize the above given function f under the side constraints that all load flow equations are fulfilled.

41.3

Components of the PowerFactory State Estimator

The State Estimator function in PowerFactory consists of several independent components, namely: 1. Preprocessing 2. Plausibility Check 3. Observability Analysis 4. State Estimation (Non-Linear Optimization) Figure 41.3.1 illustrates the algorithmic interaction of the different components. The first Preprocessing phase adjusts all breaker and tap positions according to their measured signals.

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41.3. COMPONENTS OF THE POWERFACTORY STATE ESTIMATOR

Figure 41.3.1: Variation of the PowerFactory state estimator algorithm

The Plausibility Check is sought to detect and separate out, in a second phase, all measurements with some apparent error. PowerFactory provides various test criteria for that phase of the algorithm. In a third phase, the network is checked for its Observability. Roughly speaking, a region of the network is called observable, if the measurements in the system provide enough (non-redundant) information to estimate the state of that part of the network. Finally, the State Estimation itself evaluates the state of the entire power system by solving the above mentioned non-linear optimization problem. PowerFactory provides various ways for copying with nonobservable areas of the network. In order to improve the quality of the result, observability analysis and state estimation can be run in a loop. In this mode, at the end of each state estimation, the measurement devices undergo a so-called "Bad Data Detection": the error of every measurement device can be estimated by evaluating the difference between calculated and measured quantity. Extremely distorted measurements (i.e. the estimated error is much larger than the standard deviation of the measurement device) are not considered in the subsequent iterations. The process is repeated until no bad measurements are detected any more. In the following, the distinct components of the PowerFactory state estimator are explained in detail.

41.3.1

Plausibility Check

In order to avoid any heavy distortion of the estimated network-state due to completely wrong measurements, the following Plausibility Checks can be made before the actual State Estimation is started. Every measurement that fails in any of the listed Plausibility Checks will not be considered. DIgSILENT PowerFactory 15, User Manual

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CHAPTER 41. STATE ESTIMATION • Check for consistent active power flow directions at each side of the branch elements. • Check for extremely large branch losses, which exceed their nominal values. • Check for negative losses on passive branch elements. • Check for large branch flows on open ended branch elements. • Check whether the measured branch loadings exceed the nominal loading value of the branch elements. • Node sum checks for both, active and reactive power. Each test is based on a stochastic analysis which takes into account the measurementŠs individual accuracy. The strictness of the above mentioned checking criteria can be continuously adjusted in the advanced settings. The result of the Plausibility Check is reported, for each measurement, on a detailed error status page (see Section 41.6).

41.3.2

Observability Analysis

A necessary requirement for an observable system is that the number of available measurements is equal or larger than the number of estimated variables. This verification can easily be made at the beginning of every state estimation. But it can also happen that only parts of the network are observable and some other parts of the system are not observable even if the total number of measurements is sufficient. Hence, it is not only important that there are enough measurements, but also that they are well distributed in the network. Therefore, additional verifications are made checking for every load or generator injection whether it is observable or not. The entire network is said to be observable if all load or generator injections can be estimated based on the given measurements. PowerFactory does not only solve the decision problem whether the given system is observable or not: If a network is not observable, it is still useful to determine the islands in the network that are observable. The Observability Analysis in PowerFactory is not purely based on topological arguments; it heavily takes into account the electrical quantities of the network. Mathematically speaking, the Observability Check is based on an intricate sensitivity analysis, involving fast matrix-rank-calculations, of the whole system. The result of the Observability Analysis can be viewed using the data manager. Besides, PowerFactory offers a very flexible colour representation both for observable and unobservable areas, and for redundant and non-redundant measurements (see Section 41.6.4). Observability of individual states The Observability Analysis identifies not only, for each state (i.e., load or generator injections) whether it is observable or not. It also subdivides all unobservable states into so-called "equivalence-classes". Each equivalence-class has the property that it is observable as a group, even though its members (i.e., the single states) cannot be observed. Each group then can be handled individually for the subsequent state estimation. Redundancy of measurements Typically, an observable network is overdetermined in the sense that redundant measurements exist, ˚ ˚ whichUfor the observability of the systemUdo not provide any further information. During the Observability Analysis, PowerFactory determines redundant and non-redundant measurements. Moreover, it subdivides all redundant measurements according to their information content for the systemŠs observability status. In this sense, PowerFactory is even able to calculate a redundancy level which then 984

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41.4. STATE ESTIMATOR DATA INPUT indicates how much reserve the network measurements provide. This helps the system analyst to precisely identify weakly measured areas in the network.

41.3.3

State Estimation (Non-Linear Optimization)

The non-linear optimization is the core part of the State Estimator. As already mentioned in the introduction, the objective is to minimize the weighted square sum of all deviations between calculated and measured branch flows and bus bar voltages whilst fulfilling all load flow equations. PowerFactory uses an extremely fast converging iterative approach to solve the problem based on Lagrange-Newton methods. If the Observability Analysis in the previous step indicates that the entire power system is observable, convergence (in general) is guaranteed. In order to come up with a solution for a non-observable system, various strategies can be followed: One option is to reset all non-observable states, such that some manually entered values or historic data is used for these states. An alternative option is to use so-called pseudo-measurements for nonobservable states. A pseudo-measurement basically is a measurement with a very poor accuracy. These pseudo-measurements force the algorithm to converge. At the same time, the resulting estimated states will be of correct proportions within each equivalence-class. In the remaining sections of this guide of use, the instructions related to Data Entry, Options and Constraints, and Visualization of Results are presented.

41.4

State Estimator Data Input

The main procedures to introduce and manipulate the State Estimator data are indicated in this section. For applying the PowerFactory State Estimator, the following data are required additional to standard load flow data: • Measurements – Active Power Branch Flow – Reactive Power Branch Flow – Branch Current (Magnitude) – Bus Bar Voltage (Magnitude) – Breaker Status – Transformer Tap Position • Estimated States – Loads: Active Power (P) and/or Reactive Power (Q), or the Scaling Factor, as an alternative. – Synchronous Machines: Active Power (P) and/or Reactive Power (Q) – Asynchronous Machines: Active Power (P) – Static var Systems: Reactive Power (Q) – Transformers: Tap Positions For the measurements listed above, PowerFactory uses the abbreviated names P-measurement, Qmeasurement, I-measurement, V-measurement, Breaker-measurement, and Tap position-measurement. Similarly, as a convention, the four different types of estimated states are shortly called P-state, Q-state, Scaling factor-state, and Tap position-state.

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41.4.1

Measurements

All measurements are defined by placing a so-called “External Measurement Device" inside a cubicle. For this purpose, select the device in the single-line graphic and choose from the context menu (right mouse button) "New Devices" and then “External Measurements..." (see Figure 41.4.1). Then, the new object dialogue pops up with a predefined list of external measurements. Please select the desired measurement device among this list (see Figure 41.4.2).

Figure 41.4.1: External Measurements that are located in a cubicle

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41.4. STATE ESTIMATOR DATA INPUT

Figure 41.4.2: Defining new external measurements

The following measurement devices are currently supported • (External) P-Measurement (StaExtpmea) • (External) Q-Measurement (StaExtqmea) • (External) I-Measurement, current magnitude (StaExtimea) • (External) V-Measurement, voltage magnitude (StaExtvmea) • (External) Breaker Signalization Breaker Status (StaExtbrkmea) • (External) Tap-Position Measurement Tap Position (StaExttapmea) Any number of mutually distinct measurement devices can be defined in the cubicle. Branch Flow Measurements Any branch flow measurement (StaExpmea, StaExtqmea) is defined by the following values (see figures 41.4.3 and 41.4.4): • Measured value (e:Pmea or e:Qmea, respectively) DIgSILENT PowerFactory 15, User Manual

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CHAPTER 41. STATE ESTIMATION • Multiplicator (e:Multip) • Orientation (e:i_gen) • Accuracy class and rating (e:Snom and e:accuracy) • Input status (to be found on the second page of the edit object, see Figure 41.4.4): E.g., tele-measured, manually entered, read/write protected,. . . (e:iStatus). It is important to note that the state estimator takes into account only measurements, for which the “read"-Status is explicitly set and for which the “Neglected by SE"-Status is unset.

Figure 41.4.3: Dialogue for an external P-measurement

The accuracy class and the rating are used for weighting the measurement element. In case of redundant measurements, a more accurate measurement will be higher weighted than a less accurate measurement. Using the flag “orientation", it is possible to define the meaning of the active or reactive power sign. Load orientation means that a positively measured P or Q flows into the element, generator orientation defines a positive flow as flowing out of an element. With the “multiplicator", a measured quantity can be re-rated. E.g., if a measurement instrument indicates 150kW (instead of 0.15MW), the “multiplicator" can be set to 0.001 and the measured value is set to 150 resulting in a correct value. It is important to note, that External P- and Q-measurements have the additional feature to possibly serve as a so-called (externally created) pseudo-measurement. This feature is activated by checking the corresponding box (e:pseudo). Pseudo-measurements are special measurements which are ignored during the regular calculation. They are activated in a selective manner only if the observability check found unobservable states in the network (see Section 41.5.1: Basic Setup Options for details). Current Measurements The External I-measurement (Staextimea) plays a special role and slightly differs from the External P- and Q-measurements (see Figure 41.4.5): Besides specifying the measured current magnitude (e:Imea), the user is asked to enter an assumed (or measured) value for the power factor cos𝜑 (e:cosphi and e:pf_recapr). 988

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41.4. STATE ESTIMATOR DATA INPUT

Figure 41.4.4: Second page "Status" of the dialogue for an external P-measurement

Internally, the measured current magnitude is then additionally transformed into two further measurements, namely an active and a reactive current. This is due to the fact that current magnitude does ˚ on the other hand U ˚ is essential to avoid not provide information on the direction of the flow, which U ambiguous solutions in the optimization. In this sense, an external I-measurement may play the role of up to three measurements: 1. as a current magnitude measurement. 2. as a measurement for active current. 3. as a measurement for reactive current. The decision which of these measurements shall participate in the state estimator is left to the user by checking the boxes (e:iUseMagn,e:iUseAct, and/or e:iUseReact). In any case, the corresponding ratings for the used measurement types need to be specified. This is done (accordingly to the flow measurements) by entering the pairs of fields (e:SnomMagn,e:accuracyMagn), (e:SnomAct,e:accuracyAct), and (e:SnomReact,e:accuracyReact), respectively). Voltage Measurements Voltage measurements (StaExvmea) need to be placed in cubicles as well. The measurement point then is the adjacent terminal.

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Figure 41.4.5: Dialogue for an external I-measurement

A voltage measurement basically has the same properties as a flow measurement, except, for the rating, only a single value for the accuracy needs to be specified. The corresponding internal reference is the nominal voltage of the terminal which serves as measurement point. Breaker and Tap Position Measurements Both breaker and tap position measurements are assumed to measure the corresponding discrete breaker status and tap position signal accurately. Hence, no ratings needs to be specified. Tap position measurements have a conversion table as extra feature. The conversion table allows any discrete translation mapping between external tap positions (Ext. Tap) and tap positions used by PowerFactory (PF Tap).

41.4.2

Activating the State Estimator Display Option

To access and enter data for State Estimator calculations in the appropriate elements of the grid, the pertinent “Display Options" must be selected as follows: a) Click the icon , or select from the main menu Options → User Settings. Change to the page Functions. The window shown in Figure 41.4.6 will appear. b) Enable the Display Function “State Estimator" as shown below. c) Exit the window clicking the OK button.

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41.4. STATE ESTIMATOR DATA INPUT

Figure 41.4.6: User Settings for State Estimation

With this display function enabled, a new page called “State Estimator" appears in the State Estimator related elements of the grids in the activated project. The State Estimator data manipulation of the different elements is indicated below.

41.4.3

Editing the Element Data

In addition to the measurement values, the user has to specify which quantities shall be considered as “states to be estimated" by the SE. Possible states to be optimized whilst minimizing the sum of the error squares over all measurements are all active and/or reactive power injections at generators and loads and all tap positions. Loads For each load (ElmLod), the user can specify whether its active and/or reactive power shall be estimated by the state estimator. Alternatively, the state estimator is able to estimate the scaling factor (for a given P and Q injection). The specification which parameter shall be estimated, is done by checking corresponding boxes on the “State Estimator" page of the load (see Figure 41.4.7). When these options are disabled, the load is treated as in the conventional load flow calculation during the execution of the SE.

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Figure 41.4.7: Editing element data for load

Synchronous Machines Similarly, for synchronous machines (ElmSym), the active and reactive power can be selected as a control variable for being estimated by the state estimator. Again, the user will find corresponding check boxes on the “State Estimator" page of the element. If the corresponding check box(es) are disabled, the synchronous machine behaves as in the conventional load flow calculation. Asynchronous Machines For asynchronous machines (ElmAsm), the active power may serve as a state to be estimated. Once again, the corresponding box has to be checked on the "State Estimator" page. If the corresponding check box is disabled, the asynchronous machine behaves as in the conventional load flow calculation. Static var Systems For static var systems (ElmSvs), the reactive power may serve as a state to be estimated. Again, the corresponding box has to be checked on the “State Estimator" page. If the corresponding check box is disabled, the static var system behaves as in the conventional load flow calculation. Transformers In the 2-winding transformer elements (ElmTr2), the tap position can be specified as a state to be estimated by the State Estimator (see Figure 41.4.8). Tap positions will be estimated in a continuous way (without paying attention to the given tap limits). For 3-winding transformers, any two of the three possible tap positions (HV-, MV-, and LV-side) can be selected for estimation (see Figure 41.4.9). The corresponding check boxes are found on the “State Estimator" page of the transformers. If the check box is disabled the State Estimator will treat the tap position of the transformers as in the conventional

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41.5. RUNNING SE load flow calculation.

Figure 41.4.8: Editing element data for 2-winding transformers

Figure 41.4.9: Editing element data for 3-winding transformers

41.5

Running SE

The following steps should be performed to execute the State Estimator: • Start from a case where the conventional power flow converges successfully. • Select “Additional Tools" from the Change Toolbox button ( DIgSILENT PowerFactory 15, User Manual

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.

• Select the desired options for the State Estimator run (see below). • Select Execute.

41.5.1

Basic Setup Options

Recall that the State Estimator in PowerFactory consists of three different parts (Plausibility Check, Observability Analysis, State Estimation (non-linear optimization)) and an additional precedent Preprocessing step (see Figure 41.3.1). This variation is reflected in the Basic Options dialogue (see Figure 41.5.1).

Figure 41.5.1: Editing the basic options page of the ComSe

41.5.1.1

Preprocessing

The algorithm distinguishes between breaker- and tap position-measurements on the one hand, and P,Q-,I-, and V-measurements on the other hand. Breaker- and tap position-measurements are handled in the preprocessing step, whereas the latter types are processed in the subsequent parts or the state estimator. Adapt breaker measurements If this check box is marked, all measured breakers statuses will be set to the corresponding measured signal values. Adapt tap position measurements If this check box is marked, all measured tap positions will be set to the corresponding measured values. 994

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41.5. RUNNING SE 41.5.1.2

Plausibility Check

The algorithm offers various kinds of plausibility checks to validate measurements. Each measurement undergoes the checks selected by the user. If a measurement fails any of the required tests, it will be marked as erroneous and will be neglected in all subsequent steps. A complete error report can be obtained via the error status page of each measurements (see Section 41.6). The following checks can be enabled by marking the corresponding check boxes. Consistent active power flow direction at each branch Checks for each passive branch, whether all connected P-measurements comply with a consistent power flow direction. More precisely, if some flow out of a passive element is measured while, at the same time, no flow into the element is measured, then all P-measurements connected to this element fail this test. For this check, a P-measurement is said to measure a "non-zero" flow if the measurement value is beyond a value of 𝜎 ∙ 𝑟𝑎𝑡𝑖𝑛𝑔, where 𝜎 and 𝑟𝑎𝑡𝑖𝑛𝑔 are the accuracy and the rating, respectively, of the measurement. Branch losses exceed nominal values Checks for each passive branch, whether the measured active power loss exceeds the nominal loss of the branch by a factor of 1 + 𝜀. This check only applies to passive branches which have P-measurements 𝑃 𝑚𝑒𝑎1 , . . . ,𝑃 𝑚𝑒𝑎𝑟 in each of its r connection devices. The threshold 𝜀, by which the nominal loss ∑︀𝑟 shall not be exceeded, is given by: 𝜀 = 𝑖=1 𝜎𝑖 · 𝑟𝑎𝑡𝑖𝑛𝑔𝑖 , where 𝜎𝑖 and 𝑟𝑎𝑡𝑖𝑛𝑔𝑖 are the accuracy and the rating, respectively, of measurement 𝑃 𝑚𝑒𝑎𝑖 . Negative losses on passive branches Checks for each passive branch, whether the measured active power loss is negative, i.e., if a passive branch is measured to generate active power. This check only applies to passive branches which have P-measurements 𝑃 𝑚𝑒𝑎1 , . .. , 𝑃 𝑚𝑒𝑎𝑟 in each of its r connection ∑︀𝑟devices. The measured power loss of the branch is said to be negative if it is below the threshold (− 𝑖=1 𝜎𝑖 · 𝑟𝑎𝑡𝑖𝑛𝑔𝑖 ). Large branch flows on open ended branches Checks for each connection of the element, whether the connection is an open end (i.e., switch is open, or it is connected to only open detailed switches). If the connection is open and there exists a (P-, Q-, or I-) measurement which measures a “non-zero" flow, then the corresponding measurement fails the test. Again, a measurement is said to measure a “non-zero" flow if the measurement value is beyond a value of 𝜎 · 𝑟𝑎𝑡𝑖𝑛𝑔. Branch loadings exceed nominal values Checks for each connection of the element, if the measured complex power (which is computed by the corresponding P- and/or Q-measurements) exceeds the rated complex power value by a factor of 1 + s. Here, s is the accuracy of the P- and/or Q-measurement(s). Node sum checks for active and reactive power This check applies to P- and/or Q-measurements. Checks, for each node of the network, if the node sum of the measured values in the adjacent branches is zero. If this is not the case, i.e., if the P- and/or Q-sum exceeds a certain threshold value, all adjacent P- and/or Q-measurements fail the test. Again, “not being zero" means that the sum of the measured ∑︀𝑟 values of the adjacent P-measurements 𝑃 𝑚𝑒𝑎1 , ... , 𝑃 𝑚𝑒𝑎𝑟 has magnitude below the threshold 𝑖=1 𝜎𝑖 · 𝑟𝑎𝑡𝑖𝑛𝑔 (similarly for Q-measurements). 41.5.1.3

Observability Analysis

The Observability Analysis is an optional component of the State Estimator. If activated, it checks whether the specified network is observable, i.e., whether the remaining valid P-, Q-, V-, and I-measurements (which successfully passed the plausibility checks) suffice to estimate the selected P-, Q-, Scaling Factor-, and Tap position-states. In addition, the Observability Analysis detects redundant measurements. Redundancy, in general, yields more accurate results for the following state estimation. Moreover, if the Observability Analysis detects non-observable states, upon user selection, it tries to fix DIgSILENT PowerFactory 15, User Manual

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CHAPTER 41. STATE ESTIMATION this unobservability by introducing further pseudo-measurements. Check for observability regions If the corresponding check box is marked by the user, the execution of the State Estimator will run the Observability Analysis (prior to the state Estimation optimization). Treatment of unobservable areas In case of unobservable states, the user has different options to cope with the situation:

• Stop if unobservable regions exist: The algorithm terminates with the detection of unobservable states. The Observability Analysis groups all non-observable states into different "equivalence classes". Each equivalence class consists of states that carry the same observability information through the given measurements. In other words, the given measurements can only distinguish between different equivalence classes, but not between various states of a single equivalence class. The results can be viewed by the user (see Section 41.6 Results). • Use P-, Q-values as specified by model:: If this option is selected, the algorithm internally drops the "to be estimated" flag of each non-observable state and uses the element specifications of the load flow settings instead. For example, if a P-state of a load is unobservable, the algorithm will use the P-value as entered on the load flow page. Hence, the network is made observable by reducing the number of control variables. • Use predefined pseudo-measurements: Using this option, the algorithm "repairs" the unobservability of the network by increasing the degrees of freedom. For that purpose, at the location of each non-observable state, the algorithm tries to activate a pseudo-measurement of the same kind. Hence, if a P- (Q-)state is non-observable in some element, the algorithm searches for a P-(Q-)pseudo-measurement in the cubicle of the element carrying the non-observable state. In case of a non-observable scaling-factor both, a P- and a Q-pseudo-measurement are required. The introduced pseudo-measurements remain active as long as needed to circumvent unobservable areas. • Use internally created pseudo-measurements: This option is similar to the previous one, except the algorithm automatically creates and activates a sufficient number of internal pseudomeasurements to guarantee observability. More precisely, internal pseudo-measurements are created at the locations of all elements that have non-observable P-(Q-, scaling factor-)state. For each such element, the pseudo-measurement value for P (Q, P and Q) is taken from the elementŠs load flow specification. All internally created pseudo-measurements use a common setting for their rating and accuracy, which can be specified on the advanced setup options page for the observability check. • Use predefined and internally created meas: This mode can be considered as a mixture of the latter two options. Here, in case of a non-observable state, the algorithm tries to activate a predefined pseudo-measurement of the same kind. If no corresponding pseudo-measurement has been defined, then the algorithm automatically creates an internal pseudo-measurement.

41.5.1.4

State Estimation (Non-Linear Optimization)

The non-linear optimization is the central component of the State Estimator. The underlying numerical algorithm to minimize the measurements’ overall error is the iterative Lagrange-Newton method. Run state estimation algorithm ˚ Check this box to enable the non-linear optimization. Note that after convergence of the method,Uupon ˚ user settings on the advanced state estimation option pageUPowerFactory performs a bad data check which eliminates the worst P-,Q-,V-, and I-measurements among all bad data. Observability Analysis and State Estimation are run in a loop until no further bad measurements exist (recall the algorithm variation as shown in Figure 41.3.1). 996

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41.5. RUNNING SE

41.5.2

Advanced Setup Options for the Plausibility Check

Each Plausibility Check allows for an individual strictness setting. Note that all checks rely on the same principle: namely, the given measurement values are checked against some threshold. Recall, for example, that the∑︀“node sum check for P" tests whether the active power sum at a node is below 𝑟 a threshold of 𝜀 = 𝑖=1 𝜎𝑖 · 𝑟𝑎𝑡𝑖𝑛𝑔. The user has the possibility to influence the strictness of this threshold. Therefore, the settings provide to enter so-called “exceeding factors" 𝑓 𝑎𝑐 > 0 such that the new threshold is 𝑓 𝑎𝑐 · 𝜖 instead of 𝜖. E.g., in the case of the node sum check for P, the user may define the corresponding factor fac_ndSumP. The higher the exceeding factor, the less strict the plausibility test will be. Similar exceeding factors can be specified for any of the given tests.

41.5.3

Advanced Setup Options for the Observability Check

Rastering of sensitivity matrix Internally, the Observability Check is based on a thorough sensitivity analysis of the network. For that purpose, the algorithm computes a sensitivity matrix that takes into account all measurements, on the one hand, and all estimated states on the other hand. This sensitivity matrix is discretized by rastering the continuous values. The user can specify the precision of this process by defining the number of intervals into which the values of the sensitivity matrix shall be rastered (SensMatNoOfInt), the threshold below which a continuous value is considered to be a 0 (SensMatThresh) in the discrete case, and the mode of rastering (iopt_raster). It is highly recommended to use the predefined values here. Settings for internally created pseudo-measurements If, on the basic option page, the mode for the treatment of unobservable regions is set to “use only internally created pseudo-measurements" or to “use predefined and internally created pseudo - measurements", the user may specify a default power rating (SnomPseudo) and a default accuracy class (accuracy Pseudo). These default values are used for all automatically created internal pseudomeasurements.

41.5.4

Advanced Setup Options for Bad Data Detection

Recall that the state estimator loops Observability Analysis and State Estimation as long as no further bad measurement is found (see Figure 41.3.1). The following settings allow the user to control the number of iterations performed by the loop. Maximum number of measurements to eliminate The variable iBadMeasLimit specifies an upper limit on the number of bad measurements that will be eliminated in the course of the State Estimation. Tolerance factors for bad measurement elimination A measurement is declared to be bad, if the deviation of measured against calculated value exceeds the measurement’s accuracy, i.e., if

𝑎𝑐𝑐𝑢𝑟𝑎𝑐𝑦 𝑐𝑎𝑙𝑐𝑉 𝑎𝑙 − 𝑚𝑒𝑎𝑉 𝑎𝑙 ≥ 𝑟𝑎𝑡𝑖𝑛𝑔 100

(41.2)

where calVal and meaVal are the calculated value and the measured value, respectively. The user DIgSILENT PowerFactory 15, User Manual

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CHAPTER 41. STATE ESTIMATION may modify this definition by adjusting tolerance factors for bad measurements. More precisely, a measurement is declared to be bad, if the left-hand side in equation (41.2) exceeds 𝑓 𝑎𝑐𝐸𝑟𝑟 · 𝑎𝑐𝑐𝑢𝑟𝑎𝑐𝑦/100. Here facErr > 0 is a factor which can be specified by the user for each group of measurements individually. Use the factors facErrP, facErrQ, facErrV, facErrIMagn, facErrIAct, and facErrIReact for P-, Q-, V-measurements, and the three types of the I-measurements (magnitude measure, active current measure, reactive current measure).

41.5.5

Advanced Setup Options for Iteration Control

Initialization The non-linear optimization requires an initialization step to generate an initial starting configuration. Initialization of non-linear optimization The user may specify whether the initialization shall be performed by a load flow calculation or by some flat start. If it is known in advance that the final solution of the optimization part is close to a valid load flow solution, initializing by a load flow calculation pays off in a faster convergence. Load Flow Specifies the settings of the load flow command which is taken for initialization in case no flat start is used. Stopping criteria for the non-linear optimization The non-linear optimization is implemented using an iterative Newton-Lagrange method. Recall that the goal of the optimization is to minimize the objective function f (i.e., the square sum of the weighted measurements’ deviations) under the constraint that all load flow equations are fulfilled. Mathematically speaking, the aim is to find

min 𝑓 (⃗𝑥)

(41.3)

𝑔(⃗𝑥) = 0

(41.4)

under the constraint that

where 𝑔 is the set of load flow equations that need to be fulfilled. By the Lagrange-Newton method, we thus try to minimize the resulting Lagrange function

𝐿(⃗𝑥, ⃗𝜆) = 𝑓 (⃗𝑥) + ⃗𝜆𝑇 · ⃗𝑔 (⃗𝑥)

(41.5)

with the Lagrange multipliers ⃗𝜆. The following parameters can be used to adapt the stopping criteria for this iterative process. The algorithm stops successfully if the following three issues are fulfilled: a) The maximum number of iterations has not yet been reached. b) All load flow constraint equations 𝑔(⃗𝑥) = 0 are fulfilled to a predefined degree of exactness, which means: 998

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41.6. RESULTS (a) all nodal equations are fulfilled. (b) all model equations are fulfilled. c) The Lagrange function 𝐿(⃗𝑥, ⃗𝜆) itself converges. This can be achieved if (a) either the objective function itself converges to a stationary point, or (b) the gradient of the objective function converges to zero. The following parameters serve to adjust these stopping criteria. The user unfamiliar with the underlying optimization algorithm is urged to use the default settings here. Iteration Control of non-linear optimization The user is asked to enter the maximum number of iterations. Convergence of Load Flow Constraint Equations The user should enter a maximal error for nodal equations (where the deviation is measured in kVA), and, in addition, a maximally tolerable error for the model equations (in %). Convergence of Objective Function The user is asked choose among the following two convergence criteria for the Lagrangian function: Either the function itself is required to converge to a stationary point, or the gradient of the Lagrangian is expected to converge. In the first case, the user is asked to enter an absolute maximum change in value of the objective function. If the change in value between two consecutive iterations falls below this value, the Lagrangian is assumed to be converged. In the latter case, the user is asked to enter an absolute maximum value for the gradient of the Lagrangian. If the gradient falls below this value, the Lagrangian is assumed to be converged. ˚ ˚ use the criterion on the gradient. The It is strongly recommendedUdue to mathematical precisenessUto other option might only be of advantage if the underlying Jacobian matrix behaves numerically instable which then typically results in a “toggling" of the convergence process in the last iterations. Output Two different levels of output during the iterative process can be selected.

41.6

Results

The presentation of the State Estimator results is integrated into the user interface. The solution of the non-linear optimization in the State Estimator is available via the complete set of variables of the conventional Load Flow calculations. It can be seen in the single line diagram of the grid or through the browser.

41.6.1

Output Window Report

The PowerFactory State Estimator reports the main steps of the algorithm in the output window (see Figure 41.6.1). For the Plausibility Checks, this implies the information on how many models failed the corresponding checks. For the Observability Analysis, the report contains the information on how many states were de˚ additionUhow ˚ termined to be observable, andUin many measurements were considered to be relevant for observing these states. DIgSILENT PowerFactory 15, User Manual

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Figure 41.6.1: Report in the output window

Non-linear optimization reports, in each iteration step, the following figures: • The current error of the constraint nodal equations (in VA) (Error Nodes). • The current error of the constraint model equations (Error ModelEqu). • The current value of the gradient of the Lagrangian function (Gradient LagrFunc). • The current value of the Lagrangian function (LagrFunc) • The current value of the objective function f to be minimized (ObjFunc).

41.6.2

External Measurements

Deviations Each branch flow measurement (StaExtpmea, StaExtqmea) and each voltage measurement (StaExtvmea) offers parameters to view its individual deviation between measured value and computed value by the State Estimation. The corresponding variables are: • e:Xmea: measured value as entered in StaEx* mea • e:cMeaVal: measured value (including multiplier) • e:Xcal: calculated value • e:Xdif: deviation in % (based on given rating as reference value) • e:Xdif_mea: deviation in % (based on the measured value as reference value) • e:Xdif_abs: absolute deviation in the measurementŠs unit Here X is a placeholder for P, Q, or U in the case of a P-, Q-, or V-measurement. Recall that a StaExtimea plays a special role, since a current measurement may serve as up to three measurements (for magnitude, for active current, and/or for reactive current). Hence, a current measurement has the above listed variables (with X being replaced by I) for each of the three measurement types. In order to distinguish between the three types, for a StaExtimea, the variables carry the suffixes Magn (for magnitude measurement), Act (for active current measurement), and React (for reactive current measurement). 1000

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Figure 41.6.2: StaExtvmea).

For description page for external measurements (StaExtvmea, StaExtqmea,

Error Status All measurements (StaExt*meas) which possibly participate in the Plausibility Checks, the Observability Analysis, or the State Estimation provide a detailed error description page (see figures 41.6.2 and 41.6.3) with the following information: • General Errors: – Is unneeded pseudo-measurement (e:errUnneededPseudo) – Its input status disallows calculation, i.e., input status does not allow “Read" or is already marked as “Wrong Measurement" (e:errStatus) – Measurement is out of service (e:errOutOfService) • Plausibility Check Errors: – Fails test: Consistent active power flow direction at each side of branch (e:errConsDir) – Fails test: Large branch losses (e:errExcNomLoss) – Fails test: Negative losses on passive branches (e:errNegLoss) – Fails test: Large branch flows on open ended branches (e:errFlwIfOpn) – Fails test: Branch loadings exceed nominal values (e:errExcNomLoading) – Fails test: Node sum check for P (e:errNdSumP) – Fails test: Node sum check for Q (e:errNdSumQ) • Observability Analysis Errors: DIgSILENT PowerFactory 15, User Manual

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CHAPTER 41. STATE ESTIMATION – Measurement is considered to be redundant for observability of the network, i.e., observability is already guaranteed even without this measurement. Nevertheless redundant measurements are used in the non-linear optimization since, in general, they help to improve the result (e:errRedundant). – For redundant measurements, also the redundancy level is indicated on this page (e:RedundanceLevel). The higher the redundancy level, the more measurements with a similar information content for the observability analysis exist. • State Estimation Errors: – Measurement is detected to be bad, has been removed and was not considered in last nonlinear optimization loop (e:errBadData) This detailed error description is encoded in the single parameter e:error that can be found on the top of the error status page. Again, we have the convention that, for a StaExtimea, the variables e:errRedundant, e:RedundanceLevel and e:errBadData carry the suffixes Magn (for magnitude measurement), Act (for active current measurement), and React (for reactive current measurement).

41.6.3

Estimated States

Which states participated as control variables? ˚ ˚ not all states that were Recall that Udepending on the selected "treatment of unobservable regions"U selected for estimation (see Section 41.4.3: Editing the Element Data) will necessarily be estimated by the algorithm: In case of non-observability, it may happen that some control variables need to be reset. To access the information which states were actually used as control variables, PowerFactory provides a flag for each possible state. These flags are called c:iP,Q,Scale,TapSetp for P-, Q-, Scaling factor-, and Tap-states, respectively. They can be accessed through the Flexible Data Page as Load Flow calculation parameters for the following elements: ElmLod, ElmAsm, ElmSym, ElmSvs, ElmTr2, and ElmTr3. Observability of individual state The Observability Analysis identifies, for each state, whether it is observable or not. Moreover, if the network is unobservable, it subdivides all unobservable states into “equivalence-classes". Each equivalence-class has the property that it is observable as a whole group, even though its members (i.e., the single states) cannot be observed. The equivalence classes are enumerated in ascending order 1, 2, 3, . . . .

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Figure 41.6.3: Detailed error description page for external current measurements (StaExtimea).

For this purpose, the Observability Analysis uses the flags c:iP, Q, Scale, Tap obsFlg for P-, Q-, Scaling factor-, and Tap-states, respectively. These parameters exist for all elements which carry possible states (ElmLod, ElmAsm, ElmSym, ElmSvs, ElmTr2, ElmTr3). The semantics is as follows: • a value of -2 means that the correspond state is not estimated at all. • a value of -1 means that the correspond state is unsupplied. • a value of 0 means that the corresponding state is observable. • a value of i > 0 means that the correspond state belongs to equivalence-class i.

41.6.4

Colour Representation

In addition, PowerFactory provides a special colouring mode “State Estimation" for the single line diagram which takes into account the individual measurement error statuses and the states to be estimated (see Figure 41.6.4). The colouring can be accessed by clicking the icon on the task bar. The colour representation paints the location of measurements (of a specific type) and the location of states (of a specific type) simultaneously.

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Figure 41.6.4: Colouring of measurement error statuses and estimated states.

Estimated States The user selects to colour states of a specific type (P-, Q-, Scaling factor-, or Tap position-states). Distinct colours for observable, unobservable, non-estimated states, and states with unclear observability status can be chosen. External Measurement Locations The user selects to colour measurements of a specific type (P-, Q-, V-, or I-measurements). Distinct colours for valid, redundant and invalid measurements can be chosen. A measurement is said to be valid if its error code (e:error) equals 0. Besides, measurements with a specific error code can be highlighted separately using an extra colour. To select such a specific error code press the Error Code button and choose from the detailed error description list any "AND"-combination of possible errors.

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Part V

Appendix

Appendix A

Glossary Appliance A specific physical, installed, power system component: a specific generator, transformer, busbar, etc. Example: a piece of NKBA 0.6/1kV 4 x 35sm cable, 12.4 meters long. Base Case A Base Case is considered to be the basic power system design, from which one or more alternative designs may be created and analyzed. When working with system stages, the Base Case is considered to be the highest level in a tree of hierarchical system stage designs. Block Definition A block definition is a mathematical model which may be used in other block definitions or in a composite model. Examples are all default controllers (i.e. VCO’s, PSS’s, MDM’s), and all additional user-defined DSL models. A block definition is called “primitive" when it is directly written in DSL, or “complex" when it is build from other block definitions, by drawing a block diagram. Block Diagram A block diagram is a graphical representation of a DSL model, i.e. a voltage controller, a motor driven machine model or a water turbine model. Block diagrams combine DSL primitive elements and block definitions created by drawing other block diagram. The block models thus created may (again) be used in other block diagrams or to create a Composite Frame. See also: DSL primitive, Composite Frame Branch Elements A one port element connected to a node, such as a load or a machine. See also nodes, edge elements. Busbars Busbars are particular representations of nodes. Busbars are housed in a Station folder and several busbars may be part of a station. Class A class is a template for an element, type or other kind of objects like controller block diagrams, object filters, calculation settings, etc. Examples: • The ’TypLne’ class is the type model for all lines and cables • The ’ElmLne’ class is an element model for a specific line or cable • The ’ComLdf’ class is a load-flow command DIgSILENT PowerFactory 15, User Manual

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APPENDIX A. GLOSSARY • The ’EvtSwitch’ class is an event for a switch to open or close during simulation Composite Frame A composite frame is a special block diagram which defines a new stand-alone model, mostly without in- or outputs. A composite frame is principally a circuit in which one or more slots are connected to each other. A composite frame is used to create composite models by filling the slots with appropriate objects. The composite frame thus acts as template for a specific kind of composite models. See also: Block Diagram, Slot Composite Model A composite model is a specific combination of mathematical models.These models may be power system elements such as synchronous generators, or block definitions, such as voltage controllers, primary mover models or power system stabilizers. Composite models may be used to create new objects, such as protection devices, to ’dress-up’ power system elements such as synchronous machines with controllers, prime movers models, etc., or for the identification of model parameters on the basis of measurements. Cubicle A cubicle is the connection point between a edge or branch element and a node (represented by a busbar or terminal). It may be visualized as a bay in a switch yard or a panel in a switchgear board. Elements such as CT’s, protection equipment, breakers and so forth, are housed in the cubicle, as one would expect to find in reality. DAQ Abbreviation for “Data Acquisition". Device A certain kind of physical power system components: certain synchronous machines, two-winding transformers, busbars, or other kinds of equipment. Example: a NKBA 0.6/1kV 4 x 35sm cable. DGS Abbreviation for “DIgSILENT Interface for Geographical Informations Systems". DOLE Abbreviation for “DIgSILENT Object Language for Data Exchange". DOLE was used in previous PowerFactory versions, but replaced by DGS meanwhile. Now, use DGS instead, please. The DOLE import uses a header line with the parameter name. This header must have the following structure: • The first header must be the class name of the listed objects. • The following headers must state a correct parameter name. DPL Abbreviation for “DIgSILENT Programming Language". For further information, please refer to Chapter 19 (The DIgSILENT Programming Language - DPL). Drag & Drop 1008

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“Drag&Drop" is a method for moving an object by left clicking it and subsequently moving the mouse while holding the mouse button down (“dragging"). Releasing the mouse button when the new location is reached is called “dropping". This will move the object to the new location. DSL Abbreviation for “DIgSILENT Simulation Language". For further information, please refer to Chapter 26.12 (The DIgSILENT Simulation Language (DSL)). DSL primitive A DSL primitive is the same as a primitive block definition. A DSL primitive is written directly in DSL without the use of a block diagram. Examples are PID controllers, time lags, simple signal filters, integrators, limiters, etc. DSL primitives are normally used to build more complex block definitions. See also: Block Definition, Block Diagram Edge Elements The elements between two nodes. May also be termed ’two port element.’ Source, topological studies; picture a 3 dimensional box, the corners of the box would be called the nodes, and the edges between corners are hence ’edges.’ See also nodes, branch elements. Element A mathematical model for specific appliances. Most element models only hold the appliance-specific data while the more general type-specific data comes from a type-reference. Example: a model of a piece of NKBA 0.6/1kV 4 x 35sm cable, 12.4 meters long, named “FC 1023.ElmLne". Graphics Board Window The graphics board window is a multi document window which contains one or more graphical pages. These pages may be single line graphics, virtual instrument pages, block diagrams etc. The graphics board shows page tabs when more than one page is present. These tabs may be used to change the visible page or to change the page order by drag&drop on the page tab. See also: Virtual Instrument, Block Diagram, Page Tab, Drag&Drop Grid A Grid is a collection of power system elements which are all stored in one so-called “Grid Folder" in the database. Normally, a grid forms a logical part of a power system design, like a the MV distribution system in a province, or the HV transport system in a state. Object An object is a specific item stored in the database. Examples are specific type or element models which have been edited to model specific devices or appliances. Examples: the element “FC 1023.ElmLne", the type “NKBA_4x35.TypLne", the load-flow command “3Phase.ComLdf" Node The mathematical or generic description for what are commonly known as busbars in the electrical world. In PowerFactory nodes may be represented by “Busbars" or “Terminals" of various kinds. These are treated in the same manner in mathematical terms but treated slightly differently in the database. As far as possible the user should use terminals as Busbars can be somewhat inflexible. See also Busbars, Edge Elements, Branch Elements. Operation Scenario DIgSILENT PowerFactory 15, User Manual

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APPENDIX A. GLOSSARY An Operation Scenario defines a certain operation point of the system under analysis, such as different generation dispatch, low or high load, etc.Operation Scenarios are stored inside the Operation Scenarios folder. Page Tab Page tabs are small indexes at the edge (mostly on the top or bottom) of a multi-page window. The tabs show the titles of the pages. Left-clicking the page tab opens the corresponding page. Page tabs are used in object dialogues, which often have different pages for different calculation functions, and in the Graphics Board Window, when more than one graphical page is present. Project All power system definitions and calculations are stored and activated in a project. The project folder therefore is a basic folder in the user’s database tree. All grids that make out the power system design, with all design variants, study cases, commands, results, etc. are stored together in a single project folder. Result Object A result object keeps one or more lists of parameters which are to be monitored during a calculation. Results objects are used for building calculation result reports and for defining a virtual instrument. See also: Virtual Instrument Slot A slot is a place-holder for a block definition in a composite frame. A composite model is created from a composite frame by filling one or more slots with an appropriate object. See also: Block Definition, Composite Frame. Study Case A study case is a folder which stores a list of references or shortcuts to grid or system stage folders. These folders are (de)activated when the calculation case folder is (de)activated. Elements in the grid folders that are referenced by the study case form the ’calculation target’ for all calculation functions. Elements in all other, non-active, grid folders are not considered for calculation. Besides the list of active folders, the calculation case also stores all calculations commands, results, events, and other objects which are, or have been, used to analyze the active power system. See also: Grid, System Stage System Stage A system stage is an alternative design or variation for a particular grid. A system stage is stored in a system stage folder, which keeps track of all differences from the design in the higher hierarchical level. The highest level is formed by the base grid folder. It is possible to have system stages of system stages. See also: Grid, Base Case Type A mathematical model for devices: general models for two-winding transformers, two-winding transformers, busbars, etc. A type model only contains the non-specific data valid for whole groups of power system elements. Example: a NKBA 0.6/1kV 4 x 35sm cable type, named “NKBA_4x35.TypLne" See also: System Stage, Grid

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Variation A Variation defines an expansion plan composed of one or more expansion stages, and which are chronologically activated. Variations, like all other network data, are stored inside the Network Data folder. Virtual Instrument A virtual instrument is a graphical representation of calculation results. It may be a line or bar graph, a gauge, a vector diagram, etc. A virtual instrument gets its values from a result object. See also: Result Object. Virtual Instrument Panel Virtual instrument panels are one of the possible types of pages in a graphics board window. Virtual instrument panels are used to create and show virtual instruments. Each virtual instrument panel may contain one or more virtual instruments. See also: Graphics Board Window, Virtual Instrument

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Appendix B

Hotkeys Reference B.1

Calculation Hotkeys Combination

Description

F10 F11 Ctrl + F10 Ctrl + F11 F12

Perform Load Flow calculation Perform Short-Circuit calculation Edit Load Flow calculation options Edit Short-Circuit calculation options Reset Calculation

Table B.1.1: Calculation Hotkeys

B.2

Graphic Windows Hotkeys Combination Ctrl + Ctrl + + Ctrl + Scrollen Ctrl + Doubleclick Press Mouse Scroll Wheel + Moving

Where/When Single Line Graphic, Block Diagrams, Vi’s Single Line Graphic, Block Diagrams, Vi’s Single Line Graphic, Block Diagrams, Vi’s

Description Zoom out Zoom in Zoom in/out

Busbar system

Open detailed graphic of substation

Single Line Graphic, Block Diagrams, Vi’s

Panning, Moving the visible part of the graphic

Alt + Rubberband Alt + Left-click

Textbox

Alt + Left-click (multiple times)

Element

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Only textboxes inside the rubber band are marked, no parent objects Textbox und ParentObject are marked All the connected elements will be marked 1013

APPENDIX B. HOTKEYS REFERENCE

Combination

Where/When

Description

Ctrl + A Ctrl + Alt + Shift + P

Element Dialogue

Ctrl + Alt + Moving

Marked Object

Ctrl + Alt + Moving

Marked Busbar

Ctrl + Alt + Moving

Block

Ctrl + Alt + Moving

Marked Terminal

Ctrl + Alt + Moving

Marked Node

Ctrl + C

Marked Element

Ctrl + L

Single Line Graphic, Block Diagrams

Ctrl +Left-click

Element

Ctrl + Left-click Ctrl + Left-click

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All elements are marked Save a screenshot of the complete monitor as bitmap under C:\Digsi\snapshots Single Objects from a Busbar system can be moved Single objects from a Busbar System can be increased or reduced (size) The stub length of blocks in block diagrams remains when shifting Line-Routes will move to the terminal, instead of terminal to the line Symbol of the connected branch element will not be centred

Inserting Loads/Generators Inserting Busbars/Terminals

Will open the Define Layer dialogue to create a new layer Multiselect elements, all clicked elements are marked Rotate element 90∘ Rotate element 180∘

Ctrl + M

Element Dialogue

Ctrl + Q

Single Line Graphic, Block Diagrams

Mark Element in the graphic Open Graphic Layer dialogue

Ctrl + X

Marked Element

Cut

Esc

Connecting Mode

Esc

Inserting Symbol

Interrupt the mode Interrupt and change to graphic cursor

Esc

Animation Mode

S + Left-click

Element

S +Moving

Marked Element

Shift + Moving

Marked Element

Shift + Moving

Marked Textbox

Interrupt mode Mark only the symbol of the element Move only the symbol of the element Element can only be moved in the direction of axes After rotation, textbox can be aligned in the direction of axes

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B.3. DATA MANAGER HOTKEYS

B.3

Combination

Where/When

Tab

Inserting Symbol

Left-click

Inserting Symbol

Description Change connection side of symbol Place symbol, press mouse button and move cursor in the direction of rotation to rotate the symbol in this direction

Data Manager Hotkeys Combination

Where/When

Alt + F4 Alt + Return

Right; Link

Backspace Pag (arrow: up) Pag (arrow: down)

Right

Scroll a page up

Right

Scroll a page down

Edit dialogue open

Ctrl + down)

Edit dialogue open

Ctrl + A

Mark all Save screenshot of the data manager as bitmap under C:\Digsi\snapshots Save screenshot of the complete monitor as bitmap under C:\Digsi\snapshots

Detail-Modus Marked object, marked symbol

Change to next tab

Ctrl + Alt + Shift + P

Ctrl + C Ctrl + C

Marked cell

Ctrl + D Ctrl + F Ctrl + G

Call the edit dialogue of the next object from the list and closes the current dialogue Call the edit dialogue of the previous object from the list and closes the current dialogue

Right

Ctrl + Alt + P

Ctrl + B

Close data manager Open the edit dialogue of the element Jump one directory up

Ctrl + (arrow: up)

(arrow:

Description

Copy marked object Copy the value of the marked cell Change between normal and detail mode Call the Filter dialogue

Right

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Go to line

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Combination

Ctrl + I

Where/When

Description

Right

Call the dialogue Select Element, in order to insert a new object. The object class depends on the current position

Ctrl + Left-click

Select the object

Ctrl + M

Move the object Change between the display of out of service and no relevant objects for calculation

Ctrl + O

Ctrl + Q

Ctrl + Q

Right; station, Busbar or element with a connection Right, element with more than one connection

Call the dialogue Select Station, which lists all the connected stations

Ctrl + R

Project

Activate the project

Ctrl + R

Study case

Ctrl + R

Grid

Ctrl + R

Variant

Activate study case Add the grid to the study case Insert the variant to the current study case, if the corresponding grid is not in the study case

Ctrl + Tab

Detail-Modus

Change to next tab Insert the content of the clipboard Change the focus between right and left side

Ctrl + V Ctrl + W Ctrl + X

Marked object, marked symbol

Ctrl + X

Marked cell

End

Right

Del

Right, symbol

Del

Right, cell

Esc

Right; after change in the line

F2

Right; cell

F3

F4 F5 F8

1016

Open the station graphic

Cut object Cut cell content Jump to the last column of the current row Delete marked object Delete the content of the cell Undo the change Change to edit mode Close all open dialogues and return the selected object from the top dialogue Activate/Deactivate Drag&Drop-Mode Update

Right, Graphic

Open the graphic

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B.5. OUTPUT WINDOW HOTKEYS

Combination

Where/When

Pos1

Right

Return

Right

Return

links

Return

Right; after change in the line

Return

Right; link

Shift + Left-click

B.4

Jump to the first column of the current row Call the edit dialogue of the marked object Display or close the content of the marked object Confirm changes Call the edit dialogue of the original object Select all the objects between the last marked object and the clicked row

Dialogue Hotkeys Combination

Where/When

Description

Ctrl + A

Input field

Mark the content Save screenshot of the dialogue as bitmap under C:\Digsi\snapshots Save screenshot of the complete monitor as bitmap under C:\Digsi\snapshots

Ctrl + Alt + P

Ctrl + Alt + Shift + P F1

B.5

Description

Online help

Output Window Hotkeys Combination

Where/When

Pag (arrow: up) Pag (arrow: down) Ctrl + A Ctrl + Pag (arrow: up) Ctrl + Pag (arrow: down)

Description Page up Page down Mark the content of the output window Like Ctrl + Pos1 Like Ctrl + End

Ctrl + C

Copy the market report to the clipboard

Ctrl + E

Open a new empty editor

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APPENDIX B. HOTKEYS REFERENCE

Combination

Where/When

Ctrl + End Ctrl + F

Ctrl + F3

Cursor in a Word

Set the cursor in the last position of the last row Open the Search and Replace dialogue Jump to next same word; New searched string becomes the word on which the cursor is currently positioned

Ctrl + O

Call the Open dialogue

Ctrl + P

Call the Print dialogue

Ctrl + Arrow (up) Ctrl + Arrow (down)

Page up Page down

Ctrl + Pos1 Ctrl + Shift + End Ctrl + home

Shift

+

Ctrl + Shift + F3

Cursor in a Word

End F3

Cursor in a Word

Arrow (up) Arrow (right) Arrow (down) Arrow (left) home Shift + Pag (arrow: up) Shift + Pag (arrow: down) Shift + F3

1018

Description

Cursor in a Word

Set the cursor in the first position of first row Set the cursor in the last position and marks the report in between Set the cursor in the first position and marks the report in between Jump to previous same word; New searched string becomes the word on which the cursor is currently positioned Set the cursor in the last position of the row Jump to next same word of the current searched string Set the cursor one line above Set the cursor one position after Set the cursor one line below Set the cursor one position before Set the cursor to the first position of the row Set the cursor one page up and select the in between content Set the cursor one page down and select the in between content Jump to previous same word of the current searched string DIgSILENT PowerFactory 15, User Manual

B.6. EDITOR HOTKEYS

Combination

B.6

Where/When

Description

Where/When

Description

Editor Hotkeys Combination Ctrl + O

Open file

Ctrl + S

Save

Ctrl + P

Print

Ctrl + Z

Undo

Ctrl + C

Copy

Ctrl + V

Paste

Ctrl + X

Cut

Ctrl + A

Select all

Ctrl + R

Comment selected lines Uncomment selected lines Set bookmark / Remove bookmark

Ctrl + T Ctrl + F2 Del

Delete

F2

Go to next bookmark

Shift + F2

Go to previous bookmark Jump to next same word of the current searched string Jump to previous same word of the current searched string Jump to next same word; New searched string becomes the word on which the cursor is currently positioned

F3

Cursor in a word

Shift + F3

Cursor in a Word

Ctrl + F3

Cursor in a Word

Ctrl + F

Open ’Find’ dialogue

Ctrl + G

Open ’Go to’ dialogue Open ’Find and Replace’ dialogue

Ctrl + H Ctrl + Y Ctrl + Shift + T Ctrl + Alt + T Strg + Space

Shift

+

Alt + Return

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Remove current line Replace blanks by tabs in selected text Show / Hide tabs and blanks Replace tabs by blanks in selected text Open user settings dialogue on "Editor" page 1019

APPENDIX B. HOTKEYS REFERENCE

Combination

Where/When

Delete character in front of cursor Switch between insert and replace mode

Backspace Insert Arrow (right) Shift + Arrow (right) Ctrl + Arrow (right) Ctrl + Shift + Arrow (right)

One char right Extend selection to next char right Set cursor to beginning of next word Extend selection to beginning of next word

Arrow (left)

One char left Extend selection to next char left Set cursor to beginning of previous word Extend selection to beginning of previous word

Shift + Arrow (left) Ctrl + Arrow (left) Ctrl + Shift + Arrow (left) Arrow (down) Shift + Arrow (down) Ctrl + Arrow (down) Ctrl + Shift + Arrow (down)

One line down Extend selection one line down

Arrow (up)

One line up Extend selection one line up

Shift + Arrow (up) Ctrl + Arrow (up) Ctrl + Shift + Arrow (up) home Ctrl + home Shift + home Ctrl + home

Shift

+

end Ctrl + end Shift + end Ctrl + Shift + end Pag down)

1020

Description

(arrow:

Scroll down Change selected text to lower case

Scroll up Change selected text to upper case Set cursor to first pos. in line Set cursor to beginning of text Extend selection to beginning of line Extend selection to start of text Set cursor to last pos. in line Set cursor to end of text Extend selection to end of line Extend selection to end of text Set cursor one page down

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B.6. EDITOR HOTKEYS

Combination

Where/When

Description

Shift + Pag (arrow: down)

Extend selection to one page down

Pag (arrow: up) Shift + Pag (arrow: up)

Set cursor one page up Extend selection to one page up Open manual and search for word in which cursor is placed Set break point / remove break point (but no effect)

F1 F9

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Appendix C

Technical References of Models The technical references of models in PowerFactory are organized according to categories as shown in the following table. Follow the links in the table to jump to the corresponding section. Category

Branch Elements

Generators & Loads

Power Electronic Devices

Reactive Power Compensation Controllers

Device 2-Winding Transformer (ElmTr2) 3-Winding Transformer (ElmTr3) Autotransformers Booster Transformer (ElmTrb) Overhead Lines Systems Cables Systems Series Capacitances (ElmScap) Series Reactance (ElmSind) Series Filter (ElmSfilt) Common Impedance (ElmZpu) Asynchronous Machine (ElmAsm) Doubly Fed Induction Machine (ElmAsmsc) Static Generator (ElmGenstat) PV System (ElmPvsys) Synchronous Machine (ElmSym) Loads (ElmLod) Low Voltage Load (ElmLodlv ) Partial Loads (ElmLodlvp) Motor Driven Machine (ElmMdm__X ) PWM AC/DC Converter Rectifier/Inverter Soft Starter (ElmVar ) DC/DC Converter (ElmDcdc) Neutral Earthing Element (ElmNec) Shunt/Filter Element (ElmShnt) Static Var System (ElmSvs) Station Controller (ElmStactrl) Power Frequency Control (ElmSecctrl)

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Category

Device

AC Voltage Source (ElmVac) DC Voltage Source (ElmVdc) AC Current Source (ElmIac) DC Current Source (ElmDci) Sources Impulse Source (ElmImpulse) DC Battery (ElmBattery ) DC Machine (ElmDcm) External Network (ElmXnet) Fourier Source (ElmFsrc) Current Measurement (StaImea) Power Measurement (StaPqmea) Voltage Measurement (StaVmea) Measurement Devices Phase Measurement Device (Phase Locked Loop, ElmPhi__pll) File Object (ElmFile) Digital Clock (ElmClock) Digital Register (ElmReg) Digital Devices Sample and Hold Model (ElmSamp) Trigger Model (ElmTrigger ) Analysis Functions Fast Fourier Transform (ElmFft) Miscellaneous Surge Arrester (StaSua) Table C.0.1: Technical References of Models

C.1 C.1.1

Branch Elements 2-Winding Transformer (ElmTr2)

The 2-winding transformer supports a wide range of transformer types with various vector groups, phase technologies, tap control, neutral connection options etc. As the calculation model of the 2-winding transformer changes with the phase technology, there are dedicated technical references for three-phase and single-phase 2-winding transformers: • Three phase 2-winding transformer: Technical Reference ElmTr2 3Phase • Single phase and single wire 2-winding transformer: Technical Reference ElmTr2n 1Phase

C.1.2

3-Winding Transformer (ElmTr3)

The 3-winding transformer model in PowerFactory is a 3-phase element. It requires a 3-winding transformer type (TypTr3) where the user specifies the rated data, vector groups, tap changer, etc. For a detailed description of the model the reader is referred to the Technical Reference TypTr3 of the 3-winding transformer type.

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C.1. BRANCH ELEMENTS

C.1.3

Autoransformers

The autotransformer models in PowerFactory build on the 3- and 2-winding transformer models described in the previous sections. Hence an autotransformer is defined using the same elements (i.e. the same icons in the toolbox) as used for the standard 3- and 2-winding transformers. As soon as the connection group in the transformer type is set to YNyn, the option Auto Transformer will be available in the transformer element. If the user enables this option, then the model will consider an autotransformer winding connection instead of the galvanic separated winding. For the details of the calculation model used in that case, the reader is referred to the technical references of the 2-winding C.1.1 and 3-winding C.1.2.

C.1.4

Booster Transformer (ElmTrb)

The description of the booster transformers, presenting the relations among the input parameters is given in the Technical Reference ElmTrb. The 3-phase booster transformer model requires a reference to a booster transformer type (TypTrb).

C.1.5

Overhead Lines Systems

PowerFactory handles both DC and AC lines, including all phase technologies (3ph, 2ph and single phase), with/without neutral conductor and ground wires, for both single circuit and mutually coupled parallel circuits. All these options are handled by a suitable selection of element-type combinations as summarized in Table C.1.1. The technical reference document Overhead Line Models provides a detailed description of all available line models for both the steady-state and the transient simulations. System

Phase Technology

Element

Type

DC

unipolar 1-ph 2-ph 3-ph 1-ph with neutral 2-ph with neutral 3-ph with neutral Any combination

ElmLne ElmLne ElmLne ElmLne ElmLne ElmLne ElmLne ElmTow

TypLne TypLne TypLne TypLne, TypTow, TypGeo TypLne TypLne TypLne TypTow, TypGeo

AC, single-circuits

AC, mutually coupled circuits

Table C.1.1: Overview of line models

The line element ElmLne is the constituent element of transmission lines. When referring to a type, the line element can be used to define single-circuit lines of any phase technology according to table C.1.1. Besides, the element parameter Number of Parallel Lines lets represent parallel lines without mutual coupling between each other. If the mutual coupling between parallel lines is to be modelled, then a line coupling element ElmTow shall be used. In that case, the line element ElmLne points to a line coupling element ElmTow which in turns refers to the corresponding tower type TypTow or tower geometry type TypGeo. PowerFactory further distinguishes between constant and frequency-dependent parameters models. DIgSILENT PowerFactory 15, User Manual

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APPENDIX C. TECHNICAL REFERENCES OF MODELS Constant parameters models, i.e. non frequency-dependent, are those defined in term of electrical data per unit-length. In that case, the user enters the impedance and admittance per unit-length of the line in an element type (TypLne), as explained in the technical reference. Frequency-dependent parameters model are defined instead in terms of geometrical data, i.e. the tower geometries, conductor types, etc. The user enters the configuration of the transmission system in a tower type (TypTow) or tower geometry type (TypGeo). In that case, a overhead line constant routine will calculate the electrical parameters at a given frequency or frequency range. For the details of the line constant calculation function, the reader is referred to the technical reference Overhead Line Constants.

C.1.5.1

Line (ElmLne)

The ElmLne is element used to represent transmission lines/cables. It requires a reference either to a line type TypLne, or a tower type TypTow or a tower geometry type TypGeo. The ElmLne can contain line sections as presented in Chapter 9 Network Graphics, Section 9.3.2 (Defining Line Sections). The description of the line model, is given in the attached Technical Reference Paper: Overhead Line Models.

C.1.5.2

Line Sub-Section (ElmLnesec)

Object used to represent sections of lines or cables. It can refer to any of the types defined for transmission lines or cables.

C.1.5.3

Tower Line Coupling (ElmTow)

The ElmTow is used to represent electromagnetic coupling between transmission lines. In order to define the line coupling, a TypTow/TeyGeo object determining the geometrical characteristics and the conductor type of the structure where the coupled lines are located, is required. The description of the line coupling model, presenting the relations among the input parameters is given in the attached Technical Reference Paper: Overhead Line Models.

C.1.5.4

Line Type (TypLne)

Type used to define transmission lines/cables, whose electrical parameters are known (no electromagnetic coupling between conductors is calculated in this type). The description of the line type model, presenting the relations among the input parameters is given in the attached Technical Reference Paper: Overhead Line Models.

C.1.5.5

Tower Types (TypTow/TypGeo)

Both types are used to define the tower structure of a transmission line. If TypTow or TypGeo are referred in an ElmLne, the coupling impedances and admittances of the line are calculated according to the given geometrical distribution of the conductors. The tower type requires additionally a reference to the conductor type. TypTow versus TypGeo While a tower type TypTow completely defines the overhead transmission system (i.e. defines the tower geometry and the conductors), a tower geometry type TypGeo only contains information about the 1026

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C.1. BRANCH ELEMENTS geometry of the tower. It means then, the TypTow object contains the input data relevant for the calculation of the electrical parameters (impedances and admittances) of the system, like the number of circuits, position of the conductor at tower height -i.e. tower geometry-, transposition of the circuits if applicable and the data of the phase and earth wires (if any) conductors (solid or tubular conductor, DC resistances, skin effect, etc.). It follows then that two overhead lines having the same tower geometry but different conductor types would required two different TypTow objects in the library. This is likely to happen in distribution networks where few different tower geometries are used in combination with a considerable amount of different conductor types. To simplify the data input and handling in those cases, a tower geometry type can be used instead. Then the tower geometry type TypGeo contains the definition of the tower geometry only; hence the type does not include any information about the conductor types. The user assigns the conductor types later in the element, either in the line element ElmLne or line coupling element ElmTow. These combination minimizes the data entry and allows for a flexible combination of tower geometries and conductor types. Apart from the data entry, the resulting calculation model, hence the electrical parameters of the transmission system, are in both case identical. The description of the tower models, presenting the relations among the input parameters is given in the attached Technical Reference Paper: Overhead Line Constants.

C.1.5.6

Conductor Type (TypCon)

Type used to define conductor objects. A reference to a conductor type is required in the tower types TypTow/TypGeo to define the conductors of the transmission line. The description of the conductor type model, presenting the relations among the input parameters is given in the attached Technical Reference Paper:Overhead Line Constants.

C.1.6

Cables Systems

The model of a cable system in PowerFactory builds on two types: firstly, a single-core cable type (TypCab) defines the cross-section geometry, conducting and insulating layers and properties of the materials of the single-core cable and secondly, a cable system type (TypCabsys) specifies the total number of single-core cables in the system, hence the number of coupled cables, and the installation characteristics, either buried directly underground or laid in pipes (a pipe-type cable).

C.1.6.1

Cable System (ElmCabsys)

Object used to represent a system of electromagneticaly coupled cables. The description of the cable system, presenting the relations among the input parameters and the required types is given in the attached Technical Reference Paper: Cable Systems.

C.1.6.2

Cable Type (TypCab)

Type used to define cable objects. The description of the cable type model, presenting the relations among the input parameters is given in the attached Technical Reference Paper: Cable Systems.

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C.1.7

Series Capacitances (ElmScap)

The ElmScap object represents series capacitances in PowerFactory . It can be used for various applications, e.g. • Series compensation of transmission lines • Filter capacitance The description of the Series Capacitance model, presenting the relations among the input parameters is given in the attached Technical Reference Paper: Series Capacitance

C.1.8

Series Reactance (ElmSfilt)

The ElmSfilt object represents series filter in PowerFactory . The description of the series filter model, presenting the relations among the input parameters is given in the attached Technical Reference Paper: Series Filter.

C.1.9

Series Filter (ElmSind)

The ElmSind object represents series reactances in PowerFactory . The description of the series reactance model, presenting the relations among the input parameters is given in the attached Technical Reference Paper: Series Reactance.

C.1.10

Common Impedance (ElmZpu)

The Common Impedance is a per unit impedance model including an ideal transformer. The main usage is for branches used for network reduction. The description of the common impedance model, presenting the relations among the input parameters is given in the attached Technical Reference Paper: Common Impedance.

C.2 C.2.1

Generators and Loads Asynchronous Machine (ElmAsm)

Object used to represent asynchronous machine models, requires a reference to a TypAsmo or TypAsm (obsolete) object. The description of the asynchronous machine model, presenting the relations among the input parameters is given in the attached Technical Reference Paper: Induction Machine

C.2.2

Doubly Fed Induction Machine (ElmAsmsc)

Object used to represent doubly fed induction generators, requires a reference to a TypAsmo object. Input parameters

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C.2. GENERATORS AND LOADS The description of the double feed asynchronous machine model, presenting the relations among the input parameters is given in the attached Technical Reference Paper: Doubly Fed Induction Machine

C.2.3

Static Generator (ElmGenstat)

) is an easy-to-use model to represent any kind of non-rotating The Static Generator (ElmGenstat, generators. The common characteristic of these generators is that they are all connected to the grid through a static converter and hence the name static generator. Typical applications are: • Photovoltaic Generators • Fuel Cells • Storage devices • HVDC Terminals • Reactive Power Compensations Wind generators, which are connected with a full-size converter to the grid, can be modelled as a static generator as well, because the behaviour of the plant (from the view of the grid side) is determined by the converter: • Wind Generators For a detailed description of the static generator model the reader is referred to the technical reference: Static Generator

C.2.4

PV System (ElmPvsys)

The Photovoltaic System element (ElmPvsys) is an easy-to-use model based on the Static Generator element (ElmGenstat). The PV System element models an array of photovoltaic panels, connected to the grid through a single inverter. The main difference with the static generator, is that the PV System provides an option to automatically estimate the active power set point, given the geographical location, date and time. For a detailed description of the static generator model the reader is referred to the technical reference: PV System

C.2.5

Synchronous Machine (ElmSym)

Object used to represent synchronous machine models, requires a reference to a TypSym object. Synchronous Machine Type (TypSym) Type used to define synchronous machine elements (ElmSym) The description of the synchronous machine model, presenting the relations among the input parameters is given in the attached Technical Reference Paper: Synchronous Machine

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C.2.6

Loads (ElmLod)

Object used to represent load models. Two different models are supported depending on the type selection: • General loads: requires a reference to a TypLod object (see technical reference: General Load Model) • Complex loads: requires a reference to a TypLodind object (see technical reference: Complex Load Model)

C.2.7

Low Voltage Load (ElmLodlv)

Object used to represent loads at low voltage level. The description of the low voltage load model, presenting the relations among the input parameters and the required types is given in the attached Technical Reference Paper: Low Voltage Load

C.2.8

Partial Loads (ElmLodlvp)

Object used to represent partial loads. The description of the partial load model, presenting the relations among the input parameters and the required types is given in the attached Technical Reference Paper: Partial Loads.

C.2.9

Motor Driven Machine (ElmMdm__X)

Objects used to represent motor driven machines. Three types of driven machine models are defined in PowerFactory : • ElmMdm__1 (Type 1) • ElmMdm__3 (Type 3) • ElmMdm__5 (Type 5) All types of motor driven machine models may be used in connection with a synchronous or an asynchronous motor. The description of the motor driven machine models, presenting the relations among the parameters and the connection to a motor, are given in the attached Technical Reference Paper: Motor Driven Machine

C.3 C.3.1

Power Electronic Devices PWM AC/DC Converter

Object used for a PWM converter model. Represents a self-commutated, voltage sourced AC/DC converter (capacitive DC circuit). There are two rectifier/inverter models available in PowerFactory which differentiate from each other in the number of DC connections: 1030

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C.4. REACTIVE POWER COMPENSATION • PWM AC/DC Converter - 1 DC Connection • PWM AC/DC Converter - 2 DC Connections The description of the PWM converter model, presenting the relations among the input parameters is given in the attached Technical Reference Paper: PWM Converter

C.3.2

Rectifier/Inverter

There are two rectifier/inverter models available in PowerFactory which differentiate from each other in the number of DC connections: • Rectifier/Inverter 1-DC Connection (ElmRecmono) • Rectifier/Inverter 2-DC Connection (ElmRec) Rectifier models with a single DC connection, requires a reference to a Rectifier Type (TypRec) used to define a 6 pulse bridge rectifier/inverter element with both 1-DC or 2-DC connections. The description of the rectifier model, presenting the relations among the input parameters is given in the attached Technical Reference Paper: 6-Pulse Bridge

C.3.3

Soft Starter (ElmVar)

The ElmVar object is used to represent voltage control, soft starter devises for induction motors. The ElmVar does not require a type object. The description of the soft starter model, presenting the relations among the input parameters is given in the attached Technical Reference Paper: Soft Starter

C.3.4

DC/DC Converter (ElmDcdc)

The description of the DC/DC converter model, presenting the relations among the input parameters is given in the attached Technical Reference Paper: DC/DC Converter

C.4

Reactive Power Compensation

C.4.1

Neutral Earthing Element (ElmNec)

The NEC/NER (Neutral Earthing Conductor/Neutral Earthing Reactor) is the grounding element in PowerFactory , does not require any type. The description of the NEC/NER model, presenting the relations among the input parameters is given in the attached Technical Reference Paper: Neutral Earthing Element

C.4.2

Shunt/Filter Element (ElmShnt)

The ElmShnt object is used to represent different shunt connection types.

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APPENDIX C. TECHNICAL REFERENCES OF MODELS The description of the shunt/filter model, presenting the relations among the input parameters is given in the attached Technical Reference Paper: Filter/Shunt The description of the Tap Adjustment for this element is given in the attached Technical Reference Paper: Tap Adjustment

C.4.3

Static Var System (ElmSvs)

The static var compensator system (ElmSvc) is a combination of a switched shunt capacitor bank and a thyristor controlled inductive shunt reactance. The description of the static var compensator, presenting the relations among the input parameters is given in the attached Technical Reference Paper: Static Var System

C.5 C.5.1

Controllers Station Controller (ElmStactrl)

The description of the Station Controller is given in the attached Technical Reference Paper: Station Controller The Station Controller is used for steady-state analysis. For time-domain simulation please use Common Models as described in Chapter 26: Stability and EMT Simulations, Section 26.8 (Models for Stability Analysis).

C.5.2

Power Frequency Control (ElmSecctrl)

The description of the Power Frequency Control is given in the attached Technical Reference Paper: Power Frequency Control

C.6 C.6.1

Sources AC Voltage Source (ElmVac)

The ElmVac is used to represent AC Voltage sources (single phase or three phase). The description of the AC voltage source model, presenting the relations among the input parameters and the possible types is given in the attached Technical Reference Paper: AC Voltage Source

C.6.2

DC Voltage Source (ElmVdc)

The ElmVdc is used to represent DC Voltage sources (single phase or three phase). The description of the AC voltage source model, presenting the relations among the input parameters and the possible types is given in the attached Technical Reference Paper: DC Voltage Source

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C.6. SOURCES The ElmIac is used to represent AC Current sources (only three phase model is supported). The description of the AC current source model, presenting the relations among the input parameters is given in the attached Technical Reference Paper: AC Current Source

C.6.4

DC Current Source (ElmDci)

The ElmDci models a direct current sources (three phase). The description of the DC current source model, presenting the relations among the input parameters is given in the attached Technical Reference Paper: DC Current Source

C.6.5

Impulse Source (ElmImpulse)

The Impulse Source element (ElmImpulse) is used to represent a lightning strike current waveform. It is modelled in PowerFactory as a current impulse source. It is a single-phase, single-port element and it can be connected to any AC terminal. The Impulse Source element is relevant mainly for EMT (instantaneous values) simulations and for Unbalanced Load Flow calculation. For a detailed description of the Impulse source model the reader is referred to the technical reference: Impulse Source.

C.6.6

DC Battery (ElmBattery)

The DC battery element is based on the DC Voltage source element and provides additional features specific for DC batteries (e.g. support to DC Short Circuit calculations, etc). For a detailed description of the DC battery the reader is referred to the technical reference: DC Battery.

C.6.7

DC Machine (ElmDcm)

The DC Machine element (ElmDcm) can be used to represent a direct-current generator or a directcurrent motor. This one-port element can be connected to dc terminals only. The DC Machine can be used for Load Flow and DC Short-Circuit calculations and RMS and EMT simulations. For a detailed description of the DC machine model the reader is referred to the technical reference: DC Machine.

C.6.8

External Network (ElmXnet)

Object used to represent external networks. The description of the external network model, presenting the relations among the input parameters is given in the attached Technical Reference Paper: External Network

C.6.9

Fourier Source (ElmFsrc)

Fourier source element, used to generate periodical signals in the frequency domain. The description of the Fourier source model, presenting the relations among the input parameters is given in the attached Technical Reference Paper: Fourier Source DIgSILENT PowerFactory 15, User Manual

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C.7 C.7.1

Measurement Devices Current Measurement (StaImea)

The description of the current measurement model, presenting the relations among the input parameters is given in the attached Technical Reference Paper: Current Measurement

C.7.2

Power Measurement (StaPqmea)

The description of the power measurement model, presenting the relations among the input parameters is given in the attached Technical Reference Paper: Power Measurement

C.7.3

Voltage Measurement (StaVmea)

The description of the voltage measurement model, presenting the relations among the input parameters is given in the attached Technical Reference Paper: Voltage Measurement

C.7.4

Phase Measurement Device (Phase Locked Loop, ElmPhi__pll)

The description of the phase measurement device model, presenting the relations among the input parameters is given in the attached Technical Reference Paper: Phase Measurement Device

C.7.5

Measurement File (ElmFile)

Object used to read data from a file during calculations. The description of the measurement file element, presenting the functionality of the input parameters is given in the attached Technical Reference Paper: Measurement File

C.8 C.8.1

Digital Devices Digital Clock (ElmClock)

Object used to represent clock inputs. The description of the clock model, presenting the relations among the input parameters is given in the attached Technical Reference Paper: Clock

C.8.2

Digital Register (ElmReg)

The ’Register’ (ElmReg) model in PowerFactory is a digital shifting register. With every rising edge of the clock signal the values are shifted by one, then the output is set and the input is read and stored in the register. The complete description of the Register model is given in the attached Technical Reference Paper: Register

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C.9. ANALYSIS FUNCTIONS

C.8.3

Sample and Hold Model (ElmSamp)

The ’Sample and Hold’ model of PowerFactory (ElmSamp) samples a signal, setting the output at the rising edge of a clock. The output value is constant up to the next clock pulse. The complete description of the Sample and Hold model is given in the attached Technical Reference Paper: Sample and Hold

C.8.4

Trigger Model (ElmTrigger)

The trigger model (ElmTrigger ) is used to monitor the value of a signal. If certain trigger conditions are met the model will start a trigger event. The complete description of the Trigger model is given in the attached Technical Reference Paper: Trigger

C.9 C.9.1

Analysis Functions Fast Fourier Transform (ElmFft))

Object used to represent fast Fourier transforms. The description of the fast Fourier transform model, presenting the relations among the input parameters is given in the attached Technical Reference Paper: Fast Fourier Transformation

C.10

Miscellaneous

C.10.1

Surge Arrester (StaSua)

Object used to represent MOV Surge Arrester. The complete description of the Surge Arrester model is given in the attached Technical Reference Paper: Surge Arrester

DIgSILENT PowerFactory 15, User Manual

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Appendix D

DPL Reference D.1

Class Index

This table the list of all the Classes with the corresponding DPL Methods available for each Class. Each method has a link to where it is declared and documented.

Class Index ComDpl ComEcho ComImport ComInc ComLink

ComMerge

DIgSILENT PowerFactory 15, User Manual

Execute EchoOn EchoOff GetCreatedObjects GetModificdObjects Execute ReciveData SendData CheckAssignments Compare CompareActive ExecuteRecording ExecuteWithActiveProject GetCorrespondingObject GetModification GetModificationResult GetmodifiedObjects Merge PrintComparisionReport PrintModifications Reset SetAutoAssignmentForAll SetObjectsToCompare ShowBrowser WereModificationsFound

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APPENDIX D. DPL REFERENCE

Class

ComNmink

ComOutage

ComRel3

ComRes ComShc

ComSimoutage

1038

Method AddRef Clear GetAll GetObject RemoveEvents SetObjs AnalyseElmRes CreateFaultCase RemoveEvents RemoveOutage Execute ExportFullRange FileNmResNm Execute AddCntcy Execute ExecuteCntcy ReportObjs Reset SetLimits

DIgSILENT PowerFactory 15, User Manual

D.1. CLASS INDEX

Class

Method

ComTablereport

AddColumn AddCurve AddHeader AddInvisibleFilter AddListFilter AddListFilterEntires AddPlot AddRow AddTable AddTextFilter AddXLabel DisableAutomaticRowNumbering EnableAutomaticRowNumbering SetBarLimits SetCellAccess SetCellEdit SetCellValueToBar SetCellValueToCheckbox SetCellValueToDate SetCellValueToDouble SetCellValueToInt SetCellValueToObject SetCellValueToString SetColumnHeader SetCurveValue SetDialogSize SetListFilterSelection SetNumberFormatForPlot SetSorting SetStatusText SetTextAxisDistForPlot SetTicksForPlot SetTitle BuildNodeNames GetAvailableGenPower GetAvailableGenPower GetAll IsSplitting AddCubicle Clear GetInterior Slotupd

ComUcteexp ElmAsm ElmAsmsc ElmBay

ElmBoundary ElmComp

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APPENDIX D. DPL REFERENCE

Class

ElmCoup

ElmFeeder

ElmLne

ElmNet

ElmRes

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Method Close GetRemoteBreakers IsBreaker IsClosed IsOpen Open GetAll GetBranches GetBuses GetNodesBranches GetObjs CreateFeederWithRoutes FitParams GetType GetY0m GetY1m GetZ0m GetZ1m HasRoutes HastFoutesOrSec IsCable IsNetCoupling SetCorr SetDetailed Activate CalculateInterchangeTo Deactivate AddVars Clear Draw Flush GetObj GetResData Init LoadResData ReleaseResData ResFirstValidObject ResFirstValidObjectVar ResFirstValidVar ResIndex ResNextValidObject ResNextValidObjectVar ResNextValidVar ResNval ResNvars SetAsDefault Write DIgSILENT PowerFactory 15, User Manual

D.1. CLASS INDEX

Class

ElmStactrl

ElmSubstat

ElmSym

ElmTerm

ElmTow ElmTr

ElmZone

IntCase

IntDplmap

DIgSILENT PowerFactory 15, User Manual

Method WriteDraw GetControlledHVNode GetControlledLVNode GetSetupTransformer GetSplit GetSplitCal GetSplitIndex OverwriteRA ResetRA SaveAsRA SetRA Disconnect GetAvailableGenPower IsConnected Reconnect GetMinDistance GetNextHVBus IsElectrEquivalent IsEquivalent FitParams PrintFreqDepParams IsQuadBooster GetAll GetBranches GetBuses GetNodes GetObjs Activate Deactivate Reduce Clear Contains First GetValue Insert Next Remove Size Update

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APPENDIX D. DPL REFERENCE

Class

IntDplvec

IntEvt IntForm

IntMat

IntMon

IntPlot

IntPrj

IntPrjfolder

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Method Clear Get IndexOf Insert Remove Size Sort CreateCBEvents SetText WriteOut ColLbl Get Init Invert Multiply NCol NRow Resize RowLbl Set SortToColumn AddVar ClearVars GetVar NVars PrintAllVal PrintVal RemoveVar SetAdaptY SetAutoScaleY SetScaleY Activate Deactivate GetLatestVersion HasExternalReferences Migrate Purge UpdateStatistics GetProjectFolderType IsProjectFolderType

DIgSILENT PowerFactory 15, User Manual

D.1. CLASS INDEX

Class

IntScenario

IntSstage IntThrating IntUser

IntUseman

IntVariant

IntVec

IntVersion

DIgSILENT PowerFactory 15, User Manual

Method Activate Apply Deactivate GetObjects Save Activate GetCriticalTimePhase GetRating Purge SetPassword CreateGroup CreateUser GetGroups GetUsers Activate Deactivate Reduce Get Init Resize Set Size CreateDerivedProject Rollback

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APPENDIX D. DPL REFERENCE

Class

Object

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Method AddCopy CreateObject Delete Edit GetChildren GetClass GetConnectedElms GetConnectionCount GetContents GetControlledNode GetCubicle GetFullName GetNet GetNode GetOperator GetOwner GetParent GetReferences GetSize GetUserAttribute GetVal HasResults Inom IsClass IsEarthed IsEnergized IsInFeeder IsNode IsOutOfService IsReducible IsRelevant lnm MarkInGraphics Move PasteCopy GetSystemGround SetSize SetVal ShowFullName ShowModalSelectTree snm StochEvt unm Unom VarExists

DIgSILENT PowerFactory 15, User Manual

D.1. CLASS INDEX

Class

Set

SetDesktop

SetFeeder SetFilt

SetLevelvis

DIgSILENT PowerFactory 15, User Manual

Method Add Clear Count First FirstFilt Firstmatch IsIn MarkInGraphics Next NextFilt Nextmatch Obj OutputFlexibleData Remove ShowModalBrowser ShowModalSelectBrowser ShowModelessBrowser SortToClass SortToName SortToVar AddPage DoAutoScaleX GetPage SetAdaptX SetAutoScaleX SetResults SetScaleX SetXVar Show WriteWMF GetAll GetBranches GetBuses Get AdaptWidth Aling ChangeFont ChangeFrameAndWidth ChangeLayer ChangeRefPoints Mark Reset

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Class

SetPath

SetSelect

SetTime

SetVipage

StaCubic

StaSwitch TypAsm TypAsmo

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Method AllBreakers AllClosedBreakers AllOpenBreakers GetAll GetBranches GetBuses AddRef All AllAsm AllBars AllBreakers AllClosedBreakers AllElm AllLines AllLoads AllOpenBreakers AllSym AllTypLne Clear GetAll Date SetTime SetTimeUTC Time DoAutoScaleX DoAutoScaleY GetScaleObjX GetVI SetAdaptX SetAutoScaleX SetDefScaleX SetResults SetScaleX SetStyle SetTile SetXVar AddBreaker RemoveBreaker GetAll GetConnectedMajorNodes Close IsClosed IsOpen Open CalcElParams CalcElParams

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D.2. DPL METHODS AND FUNCTIONS

Class

Method

TypLne

Variations

VisFft

VisPlot

VisPlot2

D.2

IsCable SetNomCur Activate Deactivate NewStage CreateStageObject GetActiveScheduler DoAutoScaleX AddResVar AddVars Clear DoAutoScaleX DoAutoScaleY GetScaleObjX GetScaleObjY SetAdaptX SetAdaptY SetAutoScaleX SetAutoScaleY SetCrvDesc SetDefScaleX SetDefScaleY SetScaleX SetScaleY SetXVar DoAutoScaleY2

DPL Methods and Functions

This is the list of all documented methods and global functions in DPL. Each method is linked to the class or header file where it is documented. DPL Methods & Functions

Activate

ActiveCase AdaptWidth Add AddBreaker

DIgSILENT PowerFactory 15, User Manual

ElmNet IntCase IntPrj IntScenario IntScheme IntSstage IntVariant Global SetLevelvis Set StaCubic

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Function AddCntcy AddColumn AddCopy AddCubicle AddCurve AddHeader AddInvisibleFilter AddListFilter AddListFilterEntires AddPage AddPlot AddRef AddResVars AddVars AddXLabel Aling All AllAsm AllBars AllBreakers AllClosedBreakers AllElm AllLines AllLoads AllOpenBreakers AllRelevant AllSym AllTypLne AnalyseElmRes Apply BuildNodeNames CalcElParams CalculateInterchangeTo ChangeFont ChangeFrameAndWidth ChangeLayer ChangeRefPoints CheckAssignments

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Class ComSimoutage ComTablereport Object ElmBoundary ComTablereport ComTablereport ComTablereport ComTablereport ComTablereport ActiveCase ComTablereport ComNmink SetSelect VisPlot ElmRes VisPlot ComTablereport SetLevelvis SetSelect SetSelect SetSelect SetPath SetSelect SetPath SetSelect SetSelect SetSelect SetSelect SetPath SetSelect AllRelevant SetSelect SetSelect ComRel3 IntScenario ComUcteexp TypAsm TypAsmo ElmNet SetLevelvis SetLevelvis SetLevelvis SetLevelvis SetLevelvis

DIgSILENT PowerFactory 15, User Manual

D.2. DPL METHODS AND FUNCTIONS

Function

Clear

ClearCommands ClearOutput ClearVars Close ColLbl Compare CompareActive Contains Count CreateCBEvents CreateDerivedProject CreateFaultCase CreateFeederWithRoutes CreateGroup CreateObject CreateStageObject CreateUser Date

Deactivate

Delete DisableAutomaticRowNumbering Disconnect

DoAutoScaleX

DoAutoScaleY DoAutoScaleY2 Draw EnableAutomaticRowNumbering Error Exe

DIgSILENT PowerFactory 15, User Manual

Class ComNmink ElmRes IntDplmap IntDplvec Set SetSelect VisPlot ElmBoundary Global Global IntMon ElmCoup StaSwitch IntMat ComMerge ComMerge IntDplmap Set IntEvt IntVersion ComRel3 ElmLne IntUserman Object Variations IntUserman SetTime ElmNet IntCase IntPrj IntScenario IntScheme IntVariant Object ComTablereport ElmSym SetDesktop SetVisPage VisFft VisPlot SetVisPage VisPlot VisPlot2 ElmRes ComTablereport Global Global

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Function

Execute

ExecuteCntcy ExecuteRecording ExecuteWithActiveProject Exit ExportFullRange fclose fflush FileNmResNm First FirstFilt Firstmatch FitParams Flush fopen FormatDateLT FormatDateUCT fprintf fRand fscanf fscanfsep fWrite

Get GetActiveNetworkVariations GetActiveProject GetActiveScenario GetActiveScheduler GetActiveStages GetActiveStudyCase

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Class ComDpl ComInc ComLdf ComRel3 ComShc ComSimoutage ComSimoutage ComMerge ComMerge Global ComRes Global Global ComRes IntDplmap Set Set Set ElmLne ElmTow ElmRes Global FormatDateLT FormatDateUCT fprintf Global Global Global Global IntDplvec IntMat IntVec SetFilt GetActiveNetworkVariations GetActiveProject GetActiveScenario Variations GetActiveStages GetActiveStudyCase

DIgSILENT PowerFactory 15, User Manual

D.2. DPL METHODS AND FUNCTIONS

Function

GetAll

GetAvailableGenPower GetBorderCubicles

GetBranches

GetBuses GetCaseCommand GetCaseObject GetChildren GetClass GetConnectedElms GetConnectedMajorNodes GetConnectionCount GetContents GetControlledHVNode GetControlledLVNode GetControlledNode GetCorrespondingObject GetCreatedObjects GetCriticalTimePhase GetCubicle GetDataFolder GetFlowOrientation GetFullName GetGlobalLib GetGraphBoard GetGroups GetInterior GetLanguage GetLatestVersion GetLocalLib GetMinDistance GetModification

DIgSILENT PowerFactory 15, User Manual

Class ComNmink ElmBay ElmFeeder ElmZone SetFeeder SetPath SetSelect StaCubic ElmAsm ElmAsmsc ElmSym GetBorderCubicles ElmFeeder ElmZone SetFeeder SetPath ElmFeeder ElmZone SetFeeder SetPath Global Global Object Object Object StaCubic Object Object ElmStactrl ElmStactrl Object ComMerge ComImport IntThrating Object GetDataFolder Global Object Global GetGraphBoard IntUserman ElmBoundary Global IntPrj Global ElmTerm ComMerge

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Function GetModificationResult GetModifiedObjects GetNet GetNextHVBus GetNode GetNodes GetNodesBranches GetObj GetObject GetObjects GetObjs GetOperator GetOwner GetPage GetPageLen GetParent GetPFVersion GetProjectFolder GetProjectFolderType GetRating GetRecordingStage GetReferences GetRemoteBreakers GetResData GetScaleObjX GetScaleObjY GetSettings GetSystemGround GetSize GetSplit GetSplitCal GetSplitIndex GetSetupTransformer GetSystemTime GetTime GetType GetUserAttribute GetUserManager GetUsers GetVal GetValue GetVar GetVersions GetVI

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Class ComMerge ComImport ComMerge Object ElmTerm Object ElmZone ElmFeeder ElmRes ComOutage InScenario ElmFeeder ElmZone Object Object SetDesktop Global Object Global Global IntPrjfolder IntThrating Global Object ElmCoup ElmRes SetVisPage VisPlot VisPlot Global Object Object ElmSubstat ElmSubstat ElmSubstat ElmStactrl Global Global ElmLne Object Global IntUserman Object IntDplmap IntMon IntPrj SetVisPage

DIgSILENT PowerFactory 15, User Manual

D.2. DPL METHODS AND FUNCTIONS

Function GetY0m GetY1m GetZ0m GetZ1m HasExternalReferences HasResults HasRoutes HastFoutesOrSec IndexOf Info Init Inom Insert Invert IsBreaker IsCable IsClass IsClosed IsConnected IsEarthed IsElectrEquivalent IsEnergized IsEquivalent IsIn IsInFeeder IsNetCoupling IsNode IsOpen IsOutOfService IsProjectFolderType IsQuadBooster IsReducible IsRelevant IsSplitting Inm LoadResData Mark MarkInGraphics Merge Migrate

DIgSILENT PowerFactory 15, User Manual

Class ElmLne ElmLne ElmLne ElmLne IntPrj Object ElmLne ElmLne IntDplvec Global ElmRes IntMat IntVec Object IntDplmap IntDplvec IntMat ElmCoup ElmLne TypLne Object ElmCoup StaSwitch ElmSym Object ElmTerm Object ElmTerm Set Object ElmLne Object ElmCoup StaSwitch Object IntPrjfolder ElmTr Object Object ElmBoundary Object ElmRes SetLevelvis Object Set ComMerge IntPrj

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Function

Class

Move Multiply NCol

Object IntMat IntMat IntDplmap Set IntScheme Set Set NoFinalUpdate IntMat IntMon Set ElmCoup StaSwitch Set ElmSubstat Global Global Object Global IntMon ComMerge Global ElmTow ComMerge IntMon IntPrj IntUser Random Rebuild ComLink ElmSym IntCase IntVariant ElmRes IntDplmap IntDplvec Set ComOutage ComRel3 StaCubic ComRel3 IntMon ComSimoutage ComMerge ComSimoutage SetLevelvis

Next NewStage NextFilt NextMatch NoFinalUpdate NRow NVars Obj Open OutputFlexibleData OverwriteRA ParseDateLT ParseDateUTC PasteCopy PostCommand PrintAllVal PrintComparisionReport printf PrintFreqDepParams PrintModifications PrintVal Purge Random Rebuild ReceiveData Reconnect Reduce ReleaseResData Remove RemoveEvents RemoveBreaker RemoveOutages RemoveVar ReportObjs Reset

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D.2. DPL METHODS AND FUNCTIONS

Function ResetCalculation ResetRA ResFirstValidObject ResFirstValidObjectVar ResFirstValidVar ResIndex Resize ResNextValidObject ResNextValidObjectVar ResNextValidVar ResNvar ResNvars Rollback RowLbl Save SaveAsRA SaveScenarioAs SearchObjectByForeignKey SendData Set

SetAdaptX SetAdaptY SetAsDefault SetAutoAssignmentForAll SetAutoScaleX SetAutoScaleY SetBarLimits SetCellAccess SetCellEdit SetCellValueToBar SetCellValueToCheckbox SetCellValueToDate SetCellValueToDouble SetCellValueToInt SetCellValueToObject SetCellValueToString SetColumnHeader SetConsistencyCheck SetCorr

DIgSILENT PowerFactory 15, User Manual

Class Global ElmSubstat ElmRes ElmRes ElmRes ElmRes IntMat IntVec ElmRes ElmRes ElmRes ElmRes ElmRes IntVersion IntMat IntScenario ElmSubstat Global Global ComLink IntMat IntVec SetDesktop SetVisPage VisPlot IntPlot VisPlot ComRes ComMerge SetDesktop SetVisPage VisPlot IntPlot VisPlot ComTablereport ComTablereport ComTablereport ComTablereport ComTablereport ComTablereport ComTablereport ComTablereport ComTablereport ComTablereport ComTablereport SetConsistencyCheck ElmLne

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Function SetCrvDesc SetCurvevalue SetDefScaleX SetDefScaleY SetDetailed SetDialogSize SetDiffMode SetGraphicUpdate SetLimits SetLineFeed SetListFilterSelection SetNomCurr SetNumberFormatForPlot SetObjectsToCompare SetObjs SetOutputWindowState SetPassword SetRA SetRandSeed SetResults

SetScaleX SetScaleY SetShowAllUsers SetSize SetSorting SetStatusText SetStyle SetText SetTextAxisDistForPlot SetTicksForPlot SetTile SetTime SetTimeUTC SetTitle SetVal SetXVar Show ShowBrowser ShowFullName ShowModalBrowser

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Class VisPlot ComTablereport SetVisPage VisPlot VisPlot ElmLne ComTablereport Global Global ComSimoutage Global ComTablereport TypLne ComTablereport ComMerge ComOutage Global IntUser ElmSubstat Global SetDesktop SetVisPage SetDesktop SetVisPage VisPlot IntPlot VisPlot Global Object ComTablereport ComTablereport SetVisPage IntForm ComTablereport ComTablereport SetVisPage Global SetTime ComTablereport Object SetDesktop SetVisPage VisPlot SetDesktop ComMerge Object Set

DIgSILENT PowerFactory 15, User Manual

D.2. DPL METHODS AND FUNCTIONS

Function ShowModalSelectBrowser ShowModalSelectTree ShowModelessBrowser Size Slotupd snm Sort SortToClass SortToColumn SortToName SortToVar sprintf sscanf sscanfsep StochEvt strchg strcmp strcpy strftime strlen strstr strtok SummaryGrid SetTime ToStr unm Unom Update UpdateStatistics validLDF validLDF validRMS validSHC validSIM VarExists Warn WereModificationsFound Write WriteDraw WriteOut WriteWMF

DIgSILENT PowerFactory 15, User Manual

Class Set Object Set IntDplmap IntDplvec IntVec ComMerge Object IntDplvec Set IntMat Set Set Global Global Global Object Global Global Global Global Global Global Global SummaryGrid Time Global Object Object IntDplmap IntPrj Global Global Global Global Global Object Global ComMerge ElmRes Output Window ElmRes IntForm SetDesktop

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D.3

General Functions and Methods Object General Set String Time and Date Output Window File Miscellaneous

D.3.1

Functions and methods available for all objects. Functions and methods available for sets. Functions related to strings. Functions related to time and date formatting. Functions related to the output window. Functions related to file output. Additional functions.

Object

The following list is an overview of all functions and methods which are available for all objects. AddCopy CreateObject Delete Edit SearchObjectByForeignKey GetCaseObject GetChildren GetClass GetConnectionCount GetConnectedElms GetContents GetControlledNode GetCubicle GetFullName GetNet GetNode GetOperator GetOwner GetParent GetReferences GetSystemGround GetSize GetUserAttribute GetVal HasResults IsClass IsEarthed IsEnergized IsInFeeder IsNode IsOutOfService IsReducible IsRelevant 1058

Adds a copy of an object. Creates a new object. Deletes an object. Opens the object dialogue. Searches for an object by foreign key within an active project. Returns the found class object from current study case. Returns a set of objects that are stored within the called object. Returns the class name of an object. Returns the number of electrical connections. Returns the set of connected elements. Returns the stored objects. Returns the target terminal and the resulting target voltage. Returns the object’s cubicle. Returns the full database path and name. Returns the grid in which the object is located. Returns the node(s) connected to an object. Returns the object operator. Returns the object owner. Returns the parent folder. Returns a set of all referenced objects. Returns the grounding type employed in the grounding area of the grid the object belongs to. Get the size of a vector or matrix variable. Offers read-access to user-defined attributes. Returns the value of a parameter. Checks if the object has result parameters. Checks if the object is of a certain class. Checks if a network component is earthed. Checks if a network component is energized. Returns if the object belongs to the feeder. Checks if the object is a busbar or terminal. Returns if the object is out of service. Checks if an object can be reduced in a network reduction. Returns if the object is used for calculations. DIgSILENT PowerFactory 15, User Manual

D.3. GENERAL FUNCTIONS AND METHODS MarkInGraphics Move PasteCopy SetSize SetVal ShowFullName ShowModalSelectTree StochEvt VarExists lnm snm unm Unom Inom

D.3.1.1

Marks the object in the graphic. Moves an objects to this folder. Pastes a copy of the given object(s). Sets the size of a vector or matrix variable 'VarName'. Sets the value of a vector or matrix variable 'VarName'for a given row and column. Prints the full database path and name. Shows a tree view dialog hierarchically listing currently available PowerFactory objects. Returns the first or the next state of a stochastic object. Checks a variable name. Returns the long name of a variable. Returns the short name of a variable. Returns the unit of a variable. Returns the nominal voltage. Returns the nominal current.

object.AddCopy

object object.AddCopy (set aSet | object aObj [, string | int NM1, ...]) Copies a single object or a set of objects to the target object. “Fold.AddCopy(aObj)" copies object 'aObj'into the target object 'Fold', “Fold.AddCopy(aSet)" copies all objects in 'aSet'to “Fold". “Fold.AddCopy(aObj, nm1, nm2, ...)" will copy aObj and rename it to the result of the concatenation of 'nm1', 'nm2', etc. The target object must be able to receive a copy of the objects. The function “Fold.AddCopy(aObj,...)" returns the copy of “aObj", “Fold.AddCopy(aSet)" returns “Fold", when the copy operation was successful. A “NULL" object is returned otherwise. Copying a set of objects will respect all internal references between those objects. Copying a set of lines and their types, for example, will result in a set of copied lines and line types, where the copied lines will use the copied line types. Arguments: set aSet (obligatory) : The set of objects to copy or object aObj (obligatory) : The object to copy string | int NM1 (optional) : The first part of the new name string | int NM2 (optional) : The next part of the new name ... Return value: Returns the copy that has been created. Example: The following example copies a fuse to a set of cubicles. The copies will be named “Fuse Nr.0", “Fuse Nr.1", etc. object target, copy; set Cubs; Cubs = SEL.GetAll('StaCubic'); target = Cubs.First();

DIgSILENT PowerFactory 15, User Manual

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APPENDIX D. DPL REFERENCE while (target) { copy = target.AddCopy(aFuse, 'Fuse Nr', n); if (copy) copy.ShowFullName(); target = Cubs.Next(); }

D.3.1.2

object.CreateObject

object object.CreateObject (string ClassNm [, string | int NM1, ...]) Creates a new object of class 'ClassNm'in the target object. The target object must be able to receive an object of the given class. A fatal DPL error will occur when this is not the case, causing the running DPL command to exit. “Fold.CreateObject(aClass, nm1, nm2, ...)" will create a new object of class aClass and name it to the result of the concatenation of 'nm1', 'nm2', etc. Arguments: string ClassNm (obligatory) : The class name of the object to create string | int NM1 (optional) : The first part of the object name string | int NM2 (optional) : The next part of the object name ... Return value: The created object, or NULL when no object was created. Example: The following example creates a fuse in a set of cubicles. The new fuses will be named “Fuse Nr.0", “Fuse Nr.1", etc. object target; set Cubs; int n; Cubs = SEL.GetAll('StaCubic'); target = Cubs.First(); n = 0; while (target) { target.CreateObject('RelFuse', 'Fuse Nr', n); target = Cubs.Next(); n+=1; }

D.3.1.3

Delete

void Delete ([object O | set S]) Deletes an object or a set of objects from the database. The objects are not destroyed but are moved to the recycle bin. Arguments: object O (optional): The object to delete set S (optional): The set of objects to delete Return value:

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D.3. GENERAL FUNCTIONS AND METHODS none Example: The following example removes all “Dummy" fuses from the network. The 'DummyType'variable is a local variable in the DPL script. A set of objects to delete is created first and then that set is deleted. This has the advantage that one single entry in the recycle bin is created which contains all deleted fuses. Manually restoring ('undelete') the deleted fuses, in case of a mistake, can then be done using a single restore command. object O; set S, Del; S = AllRelevant(); O = S.Firstmatch('RelFuse'); while (O) { if (O:typ_id=DummyType) { Del.Add(O); } O = S.Nextmatch(); } Delete(Del);

D.3.1.4

object.Edit

int object.Edit () Opens the edit dialogue of the object. Command objects (such as ComLdf ) will have their Execute button disabled. The execution of the running DPL script will be halted until the edit dialogue is closed again. Editing of DPL command objects (ComDPL) is not allowed. Arguments: none Return value: 1: edit dialogue was cancelled by the user 0: otherwise Example: The following example opens a line dialogue, prior to calculating a load flow.

MyLine.Edit(); Ldf.Execute();

D.3.1.5

GetCaseObject

object GetCaseObject ([string ClassName]) Returns the first found object of class “ClassName" from the currently active study case. The object is created when no object of the given name and/or class was found. Returns the default command object of class “ClassName" from the currently active calculation case. Initializes newly created commands according to the project settings. DIgSILENT PowerFactory 15, User Manual

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APPENDIX D. DPL REFERENCE The icons on the main menu for load-flow, short-circuit, transient simulation, etc., also open the corresponding default command from the currently active study case. Using “GetCaseCommand()" in a DPL script will return the same command. Arguments: string ClassName (optional) : Class name of the object (“Class"), optionally preceded by an object name without wildcards and a dot (“Name.Class"). Return value: The found or created object. Example: The following example uses the default SetTime object to change the calculation time, and then executes the load flow command with the name 'Unbalanced'.

object time, com; time = GetCaseObject('SetTime'); time:hourofyear = 1234; com = GetCaseObject('Unbalanced.ComLdf'); com.Execute();

D.3.1.6

SearchObjectByForeignKey

object SearchObjectByForeignKey (string fkey) Searches for an object by foreign key within an active project. Arguments: string fkey (obligatory) : Foreign key Return value: Object if found, otherwise NULL. Example: The following example shows how to search for an object by foreign key:

object obj; obj = SearchObjectByForeignKey('fkey '); printf('Object found: %o ', obj);

D.3.1.7

object.GetChildren

set object.GetChildren(int hiddenMode [, string filter, int subfolders]) This function returns a set of objects that are stored within the object the function was called on. In contrast to GetContents() this function gives access to objects that are currently hidden due to scheme management.

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D.3. GENERAL FUNCTIONS AND METHODS Arguments: int hiddenMode (obligatory) : Determines how hidden objects are handled. 0 1 2

Hidden objects are ignored and not added to the set Hidden objects are treated as normal objects Hidden objects are returned

string filter (optional) : Name filter, possibly containing '*'and '?'characters (see also GetContents D.3.1.11) int subfolder (optional) 0 1

(Default), the DPL command will only search object o The DPL command will additionally search all subfolders

Return value: Set of objects that are stored in the called object. Example: The following example lists all contained terminals for each substation:

object obj, substat; set objs, substats; !lists all contained terminals for each substation substats = AllRelevant('*.ElmSubstat'); for (substat = substats.First(); substat; substat = substats.Next()){ objs = substat.GetChilden(0, '*.'); printf('Terminals of substation %o', substat); for (obj = objs.First(); obj; obj = objs.Next()){ printf('%o', obj); } }

D.3.1.8

object.GetClass

string object.GetClass () Returns the class name of the object. Arguments: none Return value: The class name of the object. Example: The following example checks to see if two sets start with the same class. object O1, O2; O1 = S1.First(); O2 = S2.First(); i = O1.IsClass(O2.GetClass()); DIgSILENT PowerFactory 15, User Manual

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APPENDIX D. DPL REFERENCE if (i) { output('Both sets start with the same class'); }

D.3.1.9

object.GetConnectionCount

int object.GetConnectionCount () Returns the number of electrical connections. Arguments: none Return value: The number of connections. Example:

set aSet; int iCount,iCub; object pObj,pCub,pBus; ! list all nodes to which a 3-winding transformer is connected aSet = AllRelevant('*.ElmTr3'); for (pObj=aSet.First(); pObj; pObj=aSet.Next()) { iCount = pObj.GetConnectionCount(); for (iCub=0; iCub0.85) O.ShowFullName();} else { i = O.IsClass('ElmTr2'); if (i) { if (O:c:loading>0.95) O.ShowFullName(); } } O = S.Next(); }

D.3.1.27

object.IsEarthed

int object.IsEarthed () Checks if a network component is topologically connected to any earthed component. Earthing compoDIgSILENT PowerFactory 15, User Manual

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APPENDIX D. DPL REFERENCE nents are terminals / busbars () where attribute iEarth = 1, and grounding switches. An energized component is never considered to be earthed. Arguments: none Return value: 1: component is earthed (connected to an earthing component) 0: component is not earthed Example: The following example shows the earthed elements:

set elements; object obj; int status; elements = AllRelevant(); for (obj = elements.First(); obj; obj = elements.Next()){ status = obj.IsEarthed(); if (status = 0){ printf('Component %o is not earthed.', obj); } else if (status > 0){ printf('Component %o is earthed.', obj); } }

D.3.1.28

object.IsEnergized

int object.IsEnergized () Checks if a network component is energized. A component is considered to be energized, if it is topologically connected to a generator (ElmSym) that is set to “reference machine" or to an external set that is set to bus type “SL". All other elements are considered to be deenergized. Arguments: none Return value: 1: component is energized 0: component is deenergized -1: component has no energizing status (status unknown) Example: The following example shows the energizing status of all elements: set elements; object obj; int status;

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D.3. GENERAL FUNCTIONS AND METHODS elements = AllRelevant();

for (obj = elements.First(); obj; obj = elements.Next()) { status = obj.IsEnergized(); if (status = 0){ printf('Component %o is de-energized.', obj); } else if (status > 0){ printf('Component %o is energized.', obj); } else if (status < 0){ printf('Energizing status for %o is unknown.', obj); } }

D.3.1.29

object.IsInFeeder

int object.IsInFeeder (object Feeder [, double OptNested=0]) Returns if the object belongs to the feeder area defined by “Feeder". Arguments: object Feeder (obligatory) : The Feeder definition object double OptNested (optional) : “Nested feeders" option (1 or 0) Return value: 1 if “Feeder" is a feeder definition and the object is in the feeder area, 0 otherwise.

D.3.1.30

object.IsNode

int object.IsNode () Returns 1 if object is a node (terminal or busbar). Arguments: none Return value: 1 if object is a node, 0 otherwise

D.3.1.31

object.IsOutOfService

int object.IsOutOfService () Returns 1 if the object is currently out of service. Returns 0 otherwise. Arguments: none

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APPENDIX D. DPL REFERENCE Return value: 0 when not out of service Example: The following example checks if a line is out of service. i = MyLine.IsOutOfService(); if (i) { MyLine.ShowFullName(); }

D.3.1.32

object.IsReducible

int object.IsReducible () Checks if object can be reduced in network reduction. Arguments: none Return value: 0: object can never be reduced. 1: object can be reduced (e.g. switch, zero-length lines) 2: in principle the object can be reduced, but not now (e.g. switch that is set to be detailed) Example: The following example checks if an object is reducible:

set objs; object obj; int res; objs = AllRelevant(); for (obj = objs.First(); obj; obj = objs.Next()){ res = obj.IsReducible(); if (res = 0){ printf('Object %o is not reducible.', obj); continue; } if (res = 1){ printf('Object %o is reducible.', obj); continue; } if (res = 2){ printf('Object %o is currently not reducible.', obj); continue; } }

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D.3. GENERAL FUNCTIONS AND METHODS D.3.1.33

object.IsRelevant

int object.IsRelevant () Returns 1 if the object is currently used for calculations. Returns 0 otherwise. Arguments: none Return value: 0 when not used Example: The following example checks if a line is used in the calculation.

i = MyLine.IsRelevant(); if (i) { MyLine.ShowFullName(); }

D.3.1.34

object.MarkInGraphics

void object.MarkInGraphics () Marks the object in the currently visible graphic by crosshatching it. Arguments: none Return value: none When the currently visible single line graphic does not contain the object, nothing will happen. Example: The following example will mark a set of lines in the single line graphic. set S; object O; S = SEL.AllLines(); O = S.First(); while (O) { O.MarkInGraphics(); O = S.Next(); }

D.3.1.35

object.Move

int object.Move ([object O | set S]) DIgSILENT PowerFactory 15, User Manual

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APPENDIX D. DPL REFERENCE Moves an object or a set of objects to this folder. Arguments: object O (optional) : Object to move set S (optional) : Set of objects to move Return value: 0 on success, 1 on error. Example:

object targetobj,pObj; set AllObjs; ! move pObj to targetobj targetobj.Move(pObj); ! move all objects inside AllObjs to targetobj targetobj.Move(AllObjs);

D.3.1.36

object.PasteCopy

int object.PasteCopy (object oCopyObj | set sCopySet) This function pastes the copy of the given object(s) into this (=target) using the merge tool when source and target are inside different projects (equivalent to a manual copy&paste operation). Arguments: object oCopyObj (obligatory) : Object to be copied or set sCopySet (obligatory) : Set of object to be copied Return value: 0: Object(s) were copied 1: Error

D.3.1.37

object.SetSize

int object.SetSize (string VarName, int rows [, int cols]) Sets the size of the variable 'VarName'for an object if this variable is a vector or matrix. Arguments: string VarName (obligatory) : Object variable int rows (obligatory) : Row of the variable’s matrix or vector int cols (optional) : Column of the variable’s matrix or vector Return value: 0: 'VarName'is a valid variable name 1: Variable not found or variable is not a matrix or vector Example: The following example will set the size of the row and column to 5: 1078

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D.3. GENERAL FUNCTIONS AND METHODS object pTypSym; int res1,res2; int size,oldsize; pTypSym.GetSize('satv',oldsize); printf('Old size of vector: %d',oldsize); res1 = pTypSym.SetSize('satv',5); res2 = pTypSym.SetSize('satse',5); if (res1=1.or.res2=1) { printf('Error - parameter setse or setv no vector or matrix'); exit(); } pTypSym.GetSize('satv',size); printf('New size of vector: %d',size); See SetVal D.3.1.38

D.3.1.38

object.SetVal

int object.SetVal (string/double/object Value, string VarName, int row [, int col]) Sets the value of the variable 'VarName'for the given row and column if this variable is a vector, matrix or string. Arguments: string/double/object Value (obligatory) : Value to set string VarName (obligatory) : Object variable int row (obligatory) : Row of the variable’s matrix, vector or string. If the value for the row is '-1', the command sets all values for the variable 'VarName'starting in row 0. If the value for the row is x, the command sets all values starting in row x. int col (optional) : Column of the variable’s matrix, vector or string Return value: 0: 'VarName'is a valid variable name and row < actual number of rows and columns < actual number of columns. 1: Variable not found or variable is not a matrix or vector or row >= actual number of rows and columns >= actual number of columns. Example: The following example sets the size of the row and column to 5: object pTypSym; int irow; int size; double val1,val2; pTypSym.GetSize('satv',size); val1 = 0; val2 = 0; irow=0; while (irow100.0) { O.ShowFullName(); } O = S.Next(); }

D.3.1.40

object.ShowModalSelectTree

object object.ShowModalSelectTree ([string title, string filter]) Shows a tree view dialog hierarchically listing currently available PowerFactory objects. The first displayed element is the database root. The element on which the function is called will initially be selected. Arguments: string title (optional) : Title for dialog. If omitted, a default title will be used. string filter (optional) : Class filter. If set, a selection is only accepted if the selected object matches that filter. 1080

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D.3. GENERAL FUNCTIONS AND METHODS Return value: Currently selected object is returned, if the user selects 'Ok'. If 'Cancel'is selected, NULL is returned.

D.3.1.41

object.StochEvt

int object.StochEvt (double d [, double st]) Returns the first or the next state of a stochastic object, when the object has a valid failure model. Draws a first state, using the state probabilities, when 'st 'is omitted. Draws the next state, using Monte-Carlo simulation, when 'st'is given. The drawn state is returned. The duration of the drawn state is returned in 'd '. Arguments: double d (obligatory) : duration of the returned state double st (optional) : current state of the object Return value: First or the next state of a stochastic object Example: The following example prints the states of a line for a year. This is a small example of a chronological Monte-Carlo simulation.

SetRandSeed(1); st = Line.StochEvt(t); while (tMinCurrent) { Shv.Add(O); } O = S.Next(); } See also Unom D.3.1.46

D.3.1.45

object.unm

string object.unm (string VarName) Returns the unit of the variable. Arguments: string VarName (obligatory) : The variable name Return value: The unit name. Example: See lnm D.3.1.43 See also snm D.3.1.47

D.3.1.46

object.Unom

double object.Unom () Returns the nominal voltage of the object. Arguments:

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APPENDIX D. DPL REFERENCE none Return value: The nominal voltage Example: The following example collects all high voltage lines. The value VoltageLevel is an input parameter. set S, Shv; object O; double U; S = SEL.AllLines(); O = S.First(); while (O) { U = O.Unom(); if (U>VoltageLevel) { Shv.Add(O); } O = S.Next(); } See also Inom D.3.1.44

D.3.1.47

object.snm

string object.snm (string VarName) Returns the short variable name. By default, the short name equals the long variable name. In some cases, the variable also has a short name which is used to save space in reports or dialogues. Arguments: string VarName (obligatory) : The variable name Return value: The short name. Example: See lnm D.3.1.43 See also unm D.3.1.45

D.3.2

General Set AllRelevant Add Clear Count First FirstFilt Firstmatch

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Returns all calculation relevant objects. Adds an object. Removes all objects from the set. Returns the number of stored objects. Returns the first objects. Returns the first matching object. Returns the first matching object. DIgSILENT PowerFactory 15, User Manual

D.3. GENERAL FUNCTIONS AND METHODS IsIn MarkInGraphics Next NextFilt Nextmatch Obj OutputFlexibleData Remove ShowModalBrowser ShowModalSelectBrowser ShowModelessBrowser SortToClass SortToName SortToVar

D.3.2.1

Searches for an object in the set. Marks the objects in the graphic. Returns the next object. Returns the next matching object. Returns the next matching object. Returns the object at index i. Outputs all Flexible Data defined for the objects in the set to the output window. Removes an object. Opens a modal browser window and lists all objects contained in the set. Opens a modal browser window and lists all objects contained in the set. Opens a modeless browser window and lists all objects contained in the set. Sorts the objects to their class. Sorts the objects to their names. Sorts the objects to a variable value.

AllRelevant

set AllRelevant ([string classname, int incOutofService, int elementsOnly]) Returns a set with calculation relevant objects, i.e. the objects which are used by the calculations. The set of calculation relevant objects is determined by the currently active study case and the currently active grids. Objects which are out-of-service are ignored when i=0, but are included when i=1 or when i is omitted. A wildcard argument can be given, and only objects whose name and class-name satisfy this wildcard will be returned. The argument 'elementsOnly'can be used to increase the performance if only elements are filtered, e.g. ElmLne, ElmSym, ... . Arguments: string classname (optional) : Classname(s) with wildcards int incOutofService (optional) : Flag to include out of service objects int elementsOnly (optional) : Argument to increase the performance Return value: The set of all calculation relevant objects, according to the given class-name wildcards Example 1: The following example writes the names of calculation relevant objects for various settings. set S; object O; printf('all objects, including out-of-service:'); S = AllRelevant(); for (O=S.First(); O; O=S.Next()) { O.ShowFullName(); } printf('all objects, excluding out-of-service:'); DIgSILENT PowerFactory 15, User Manual

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APPENDIX D. DPL REFERENCE S = AllRelevant(0); for (O=S.First(); O; O=S.Next()) { O.ShowFullName(); } printf('all busbars and terminals,'); printf('including out-of-service:'); S = AllRelevant('*.StaBar,*.'); for (O=S.First(); O; O=S.Next()) { O.ShowFullName(); } printf('all lines, excluding out-of-service:'); S = AllRelevant('*.ElmLne',0); for (O=S.First(); O; O=S.Next()) { O.ShowFullName(); } Example 2: The following example writes the full name of all relevant busbars and terminals in the output window. set S; object O; S = AllRelevant('*.StaBar,*.'); ! for (O=S.First(); O; O=S.Next()) { O.ShowFullName(); }

D.3.2.2

includes out-of-service objects

set.Add

int set.Add ([object O | set S]) Adds an object or all objects from a set to the set. Arguments: One of the following two parameter has to be given object O (optional) : an object set S (optional) : a set of objects Return value: 0 on success Example: The following example collects all loads and lines and the first breaker from the general DPL selection

set S, Sbig; object O; Sbig = SEL.AllLines(); S = SEL.AllLoads(); Sbig.Add(S); S = SEL.AllBreakers(); O = S.First(); Sbig.Add(O); 1086

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D.3. GENERAL FUNCTIONS AND METHODS D.3.2.3

set.Clear

void set.Clear() Clears the set. Arguments: none Return value: none Example: The following example clears a set set Sbig; Sbig = SEL.AllLines(); ... Sbig.Clear();

D.3.2.4

set.Count

int set.Count () Returns the number of objects in the set. Arguments: none Return value: The number of objects in the set. Example: The following example terminates the DPL script when the general selection is found to contain no lines. set S; int n; S = SEL.AllLines(); n = S.Count(); if (n=0) { exit(); }

D.3.2.5

set.First

object set.First() Returns the first object in the set. Arguments: DIgSILENT PowerFactory 15, User Manual

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APPENDIX D. DPL REFERENCE none Return value: The first object or 0 when the set is empty Example: The following example writes the full names of all line in the general selection to the output window. set S; object O; S = SEL.AllLines(); O = S.First(); while (O) { O.ShowFullName(); O = S.Next(); } See also NextD.3.2.10 .

D.3.2.6

set.FirstFilt

object set.FirstFilt (string WildCard) Returns the first object from the set which name matches the wildcard. The wildcard may contain (parts of the) name and classname. Arguments: string WildCard (obligatory) : class name, possibly containing '*'and '?'characters Return value: The first matching object, or NULL when no first object exists. Example: The following example writes all two and three winding transformers whose name start with a 'T'to the output window set S; object O; S = AllRelevant(); O = S.FirstFilt('T*.ElmTr?'); while (O) { O.ShowFullName(); O = S.NextFilt(); } See also NextFilt D.3.2.11

D.3.2.7

set.Firstmatch

object set.Firstmatch (string WildCard)

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D.3. GENERAL FUNCTIONS AND METHODS set.Firstmatch (string) is obsolete. Use set.FirstFilt (string) instead.

D.3.2.8

set.IsIn

int set.IsIn (object O) Checks if the set contains object 'O'. Arguments: object O (obligatory) : an object Return value: 1 if the O is in the set. Example: The following example collects all not selected lines. set Ssel, Srel, Snsel; object lne; int i; Ssel = SEL.AllLines(); Srel = AllRelevant(); lne = Srel.Firstmatch('ElmLne'); while (lne) { i = Ssel.IsIn(lne); if (i=0) Snsel.Add(lne); lne = Srel.Nextmatch(); }

D.3.2.9

set.MarkInGraphics

void set.MarkInGraphics () Marks all objects in the set in the currently visible graphic by hatch crossing them. Arguments: none Return value: none Example: The following example will try to mark a set of lines in the single line graphic. set S; object O; S = SEL.AllLines(); S.MarkInGraphics();

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APPENDIX D. DPL REFERENCE D.3.2.10

set.Next

object set.Next () Returns the next object in the set. Arguments: none Return value: The next object or 0 when the last object has been reached Example: The following example writes the full names of all line in the general selection to the output window. set S; object O S = SEL.AllLines(); O = S.First(); while (O) { O.ShowFullName(); O = S.Next(); } See also First D.3.2.5 .

D.3.2.11

set.NextFilt

int set.NextFilt () Returns the next object from the set which name matches the wildcard. Arguments: none Return value: The next object, or NULL when no next object exists. Example: The following example writes all two and three winding transformers to the output window set S; object O; S = AllRelevant(); O = S.FirstFilt('*.ElmTr'); while (O) { O.ShowFullName(); O = S.NextFilt(); } See also FirstFilt D.3.2.6

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D.3. GENERAL FUNCTIONS AND METHODS D.3.2.12

set.Nextmatch

int set.Nextmatch () set.Nextmatch () is obsolete. Use set.NextFilt () instead.

D.3.2.13

set.Obj

int set.Obj (int Index) Returns the object at the given index in the set. Arguments: int Index (obligatory) : the index of the object. Return value: The object at the given index in the set, when 'Index'is in range, NULL otherwise.

D.3.2.14

set.OutputFlexibleData

void set.OutputFlexibleData() Has identical functionality to that implemented in the Object Filter dialogue, whereby the user can rightclick on a single row or multiple rows in a Flexible Data page and select Output . . . Flexible Data. The OutputFlexibleData() function assumes that the user has already defined a Flexible Data page for the objects in the set. Upon execution of this function, all Flexible Data defined for the objects in the set is output to the PowerFactory output window in a tabular format. Arguments: none Return value: none Example: The following example collects all elements of classes ElmLne and (lines and terminals, respectively) which are relevant to the calculation and output their defined Flexible Data to the output window: set sElms; sElms = AllRelevant('*.ElmLne,*.'); sElms.OutputFlexibleData();

D.3.2.15

set.Remove

int set.Remove (object O) Removes an object from the set. Arguments: object O (obligatory) : the object to remove DIgSILENT PowerFactory 15, User Manual

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APPENDIX D. DPL REFERENCE Return value: 0 on success Example: The following example removes al short lines from a set set S; object O; double l; S = SEL.AllLines(); O = S.First(); while (O) { l = O:dline; if (l -1){ iRet = fscanfsep(0,'%s',sRes,';',1); if (iRet = -1){ break; } printf('%s\n',sRes); } fclose(0);

D.3.7

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Miscellaneous

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D.3. GENERAL FUNCTIONS AND METHODS EchoOn EchoOff exit fRand GetBorderCubicles GetLanguage GetPageLen GetSettings GetUserManager Input NoFinalUpdate Random Rebuild SetConsistencyCheck SetDiffMode SetRandSeed SetShowAllUsers

D.3.7.1

Re-activates the user interface. Freezes (de-activates) the user-interface. Terminates a DPL script immediately. Returns stochastic numbers according to a probability distribution. Returns the border cubicles of the parent substation. Returns the current language. Returns the number of lines per page. Offers read-only access to some selected PowerFactory settings. Offers access to the user manager object. Offers possibility to get user input during the execution of a DPL script. Prevents EchoOn() at end of execution. Returns a random number. Updates the currently visible diagram without closing page or desktop. Enables or disables the consistency check. Allows switching between base and compare case results. Initializes the random number generator. Enables or disables the filtering of all available users in data manager.

EchoOn

void EchoOn () Re-activates the user interface. Arguments: none Return value: none Example: The following example de-activates the user-interface to speed up the calculations, after which the user-interface is re-activated again. EchoOff(); ..

do some calculation ...

EchoOn();

See also EchoOff() D.3.7.2. See also NoFinalUpdate() D.3.7.11.

D.3.7.2

EchoOff

void EchoOff () Freezes (de-activates) the user-interface. For each EchoOff(), an EchoOn() should be called. An EchoOn() is automatically executed at the end of a DPL execution, except for when NoFinalUpdate() has been called. DIgSILENT PowerFactory 15, User Manual

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APPENDIX D. DPL REFERENCE Arguments: none Return value: none Example: The following example de-activates the user-interface to speed up the calculations, after which the user-interface is re-activated again. EchoOff(); .. do some calculation ... EchoOn(); See also EchoOn() D.3.7.1. See also NoFinalUpdate() D.3.7.11.

D.3.7.3

exit

exit () The exit() command terminates a DPL script immediately. If called within a subscript, only the subscript itself will be terminated. In this case, execution will continue in the calling parent script. Arguments: The exit() command has no arguments. Return value: The return value is ’0’ as default, if no other value will be assigned or if the ’exit()’ command is not executed. Example:

int in; int sum; !sums up all entered numbers while(1){ input(in, 'Enter a number please (75) { 1242

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D.7. POWERFACTORY COMMANDS PrepOut.AddRef(O); } O = S.Nextmatch(); } PrepOut.Execute();

D.7.8.2

ComNmink.Clear

void ComNmink.Clear () Empties the selection. Arguments: none Return value: none Example: The following example creates a selection of all loads. PrepOut.Clear(); S = AllRelevant(); O = S.Firstmatch('ElmLne'); while (O) { if (O:c:loading>75) { PrepOut.AddRef(O); } O = S.Nextmatch(); } PrepOut.Execute();

D.7.8.3

ComNmink.GetAll

set ComNmink.GetAll (string ClassName) Returns all objects which are of the class 'ClassName'. Arguments: string ClassName (obligatory) : The object class name. Return value: The set of objects Example: The following example writes all three winding transformers in the preparation command to the output window. set S; object O; DIgSILENT PowerFactory 15, User Manual

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APPENDIX D. DPL REFERENCE S = Prep.GetAll('ElmTr3'); O = S.First(); while (O) { O.ShowFullName(); O = S.Next(); }

D.7.9

Reliability Assessment (ComRel3) Methods Execute RemoveOutages RemoveEvents AnalyseElmRes CreateFaultCase

D.7.9.1

Executes the command. Removes contingency definitions. Removes events stored in contingencies. Evaluates results object created in last calculation. Creates fault cases for the components stored in the set 'Components'.

ComRel3.Execute

int ComRel3.Execute () Executes the Level 3 reliability assessment calculations. Arguments: none Return value: 0 on success Example: The following example executes a ComRel3 Command named 'Rel3' Rel3.Execute();

D.7.9.2

ComRel3.RemoveOutages

void ComRel3.RemoveOutages () Removes all contingency definitions (*.ComOutage) stored inside the command. This is exactly the same like pressing the button named “Delete Contingencies" in the dialogue box of the command. Arguments: int msg (optional) : 1 0

show info message in output window (taken by default), do not show a message

Return value: none Example: 1244

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D.7. POWERFACTORY COMMANDS

The following example removes all ComOutage objects stored inside the ComRel command in the study case. object aCmd; aCmd = GetCaseObject('*.ComRel3'); ! get the command from study case if (aCmd) { aCmd.RemoveOutages(0); ! suppress info message }

D.7.9.3

ComRel3.RemoveEvents

void ComRel3.RemoveEvents (string type, int info) Removes events stored inside the contingencies (*.ComOutage) inside the command. Arguments: string type (optional): none 'Lod' 'Gen' 'Switch'

remove all events stored inside the ComOutages inside ComRel3 remove all EvtLod remove all EvtGen' remove all EvtSwitch'

int info (optional): 1 0

show info message in output window (default) do not show info message

Return value: none Example: The following example shows how to remove events from the ComOutage commands stored inside ComRel3: object aCmd; aCmd = GetCaseObject('*.ComRel3 '); ! get the command from study case if (aCmd) { aCmd.RemoveOutages('Lod');! delete all EvtLod aCmd.RemoveOutages('Gen');! remove all EvtGen aCmd.RemoveOutages(0); ! delete remaining, suppress info message }

D.7.9.4

ComRel3.AnalyseElmRes

int ComRel3.AnalyseElmRes (int error) Evaluate the results object created by the last calculation. Performs exactly the same like pressing the

DIgSILENT PowerFactory 15, User Manual

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APPENDIX D. DPL REFERENCE button 'Perform Evaluation of Result File'in the dialogue box of the command. Arguments: int error (optional): 0 1

do not display an error message (default) display error messages in case of errors

Return value: 0 on success, !=0 on error. Example: The following example shows how to call the evaluation of the results. object int

aCmd, aResFile; iError;

aCmd = GetCaseObject('*.ComRel3'); ! get the command from study case if (aCmd) { iError=aCmd.AnalyseElmRes(0); ! hide error message if (iError) { ! display my own error message aResFile = aCmd:p_resenum; if (aResFile) { Error('Evaluation of results %s failed', aResFile:loc_name); } } }

D.7.9.5

ComRel3.CreateFaultCase

int ComRel3.CreateFaultCase (set Components, int iLevel [, int iCreateSwtEvts]) Creates fault cases for the components stored in the set 'Components'. Arguments: set Components (obligatory) : Components to create fault case for. int iLevel (obligatory) : Fault case level 0: Define simultaneous fault case 1: Define n-1 fault case(s) 2: Define n-2 fault case(s) int iCreateSwtEvts (optional) : Create switch events for boundary circuit breakers. 0: Do not create switch events (default) 1: Create switch events Return value: !=0 in case of errors

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D.7. POWERFACTORY COMMANDS

D.7.10

DPL Command (ComDpl) Methods

D.7.10.1

ComDpl.Execute

int ComDpl.Execute (user defined arguments) Executes an external DPL script as a subroutine. Arguments: user defined arguments Return value: 0 on success Example: The following example performs a load-flow and calls the DPL subroutine “CheckVoltages" to check the voltage conditions. int err; err = Ldf.Execute(); if (.not.err) err = CheckVoltages.Execute(0.94, 1.05); if (err) printf('Voltage conditions are violated');

D.7.11

ComImport Methods

GetCreatedObjects GetModifiedObjects

D.7.11.1

Returns the created objects after execution of a DGS import. Returns the modified objects after execution of a DGS import.

ComImport.GetCreatedObjects

set ComImport.GetCreatedObjects () Returns the created objects after execution of a DGS import. Please note: The sets of created objects is only available directly after a DGS import and only at the command instance that has been executed. The sets are not stored on database. Arguments: none Return value: Collection of objects that have been created during DGS import. Example: The following example returns the created objects after execution of a DGS import: set created; DIgSILENT PowerFactory 15, User Manual

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APPENDIX D. DPL REFERENCE object obj; ImportCmd.Execute(); !execute dgs import printf('Created objects:'); created = ImportCmd.GetCreatedObjects(); for(obj = created.First(); obj; obj = created.Next()) { printf('%o', obj); }

D.7.11.2

ComImport.GetModifiedObjects

set ComImport.GetModifiedObjects () Returns the modified objects after execution of a DGS import. Please note: The sets of created objects is only available directly after a DGS import and only at the command instance that has been executed. The sets are not stored on database. Arguments: none Return value: Collection of objects that have been modified during DGS import. Example: The following example returns the modified objects after execution of a DGS import: set modified; object obj; ImportCmd.Execute(); !execute dgs import printf('\nModified objects:'); modified = ImportCmd.GetModifiedObjects(); for(obj = modified.First(); obj; obj = modified.Next()) { printf('%o', obj); }

D.7.12

ComMerge Methods

ExecuteWithActiveProject Compare CompareActive ExecuteRecording

PrintComparisonReport SetAutoAssignmentForAll 1248

Compares objects according to settings in ComMerge object and shows merge browser. Active project ignored. Compares objects according to settings in ComMerge object. Merge browser is not shown. Compares objects according to settings in ComMerge object. Merge browser is not shown. Active project ignored. Compares objects according to settings in ComMerge object and shows merge browser. Sets “recording mode" to record modifications in the active scenario and/or expansion stage. Prints all compare objects as a report to the output window. Sets the assignment of all compared objects automatically. DIgSILENT PowerFactory 15, User Manual

D.7. POWERFACTORY COMMANDS CheckAssignments ShowBrowser Merge Reset WereModificationsFound PrintModifications SetObjectsToCompare GetCorrespondingObject GetModification GetModificationResult GetModifiedObjects

D.7.12.1

Checks if all assignments are correct and merge can be done. Shows merge browser with initialized settings and all compared objects. Checks assignments, creates target and prints merge report to output window. Resets/clears and deletes all temp. object sets, created internally for the comparison. Checks, if modifications were found in comparison. Prints modification for given objects if found in comparison. Sets objects taken as top level objects for comparison. Searches corresponding object for given object. Gets modification of corresponding objects between 'Base'and 'Mod1'or 'Mod2'. Gets modification of compared objects between 'Mod1'and 'Mod2'. Gets all objects with a certain modification status from comparison.

ComMerge.ExecuteWithActiveProject

void ComMerge.ExecuteWithActiveProject () Compares objects according to settings in ComMerge object and shows merge browser. Active project ignored. Arguments: none Return value: none

D.7.12.2

ComMerge.Compare

int ComMerge.Compare () Compares objects according to settings in ComMerge object. Merge browser is not shown. Arguments: none Return value: none

D.7.12.3

ComMerge.CompareActive

int ComMerge.Compare () Compares objects according to settings in ComMerge object. Merge browser is not shown. Active project ignored.

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APPENDIX D. DPL REFERENCE Arguments: none Return value: none

D.7.12.4

ComMerge.ExecuteRecording

int ComMerge.ExecuteRecording () Compares objects according to settings in ComMerge object and shows merge browser. Sets “recording mode" to record modifications in the active scenario and/or expansion stage. Arguments: none Return value: none

D.7.12.5

ComMerge.PrintComparisonReport

void ComMerge.PrintComparisonReport (int mode) Prints all compare objects as a report to the output window. Arguments: int mode (obligatory): 0: no report 1: only modified compare objects 2: all compare objects Return value: none

D.7.12.6

ComMerge.SetAutoAssignmentForAll

void ComMerge.SetAutoAssignmentForAll (int conflictVal) Sets the assignment of all compared objects automatically. Arguments: int conflictVal (obligatory): Assignment of compared objects with undefined auto values (e.g. conflicts) Return value: none

D.7.12.7

1250

ComMerge.CheckAssignments

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D.7. POWERFACTORY COMMANDS int ComMerge.CheckAssignments () Checks if all assignments are correct and merge can be done. Arguments: none Return value: 0: 1: 2: 3: 4:

ok, canceled by user, missing assignments found, conflicts found, error

D.7.12.8

ComMerge.ShowBrowser

int ComMerge.ShowBrowser () Shows merge browser with initialized settings and all compared objects. Arguments: none Return value: 0: browser was left with ok button, 1: browser was left with cancel button, 2: error

D.7.12.9

ComMerge.Merge

void ComMerge.Merge (int printReport) Checks assignments, creates target and prints merge report to output window. Arguments: int printReport (obligatory): 1: merge report is printed (default) 0: merge report is not printed -> always set to 0 in paste and split mode Return value: none

D.7.12.10

ComMerge.Reset

void ComMerge.Reset () Resets/clears and deletes all temp. object sets, created internally for the comparison. Arguments:

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APPENDIX D. DPL REFERENCE none Return value: none

D.7.12.11

ComMerge.WereModificationsFound

int ComMerge.WereModificationsFound () Checks, if modifications were found in comparison. Arguments: none Return value: 1: Modifications found in comparison, 0: All objects in comparison are equal

D.7.12.12

ComMerge.PrintModifications

int ComMerge.PrintModofications (set | object obj) Prints modification for given objects if found in comparison. Arguments: set | object obj (obligatory): Object or set of objects for which the modifications are printed. Return value: 1: Modifications were printed, 0: Object(s) not found in comparison

D.7.12.13

ComMerge.SetObjectsToCompare

void ComMerge.SetObjectsToCompare (object base [, object mod1, object mod2]) Sets objects taken as top level objects for comparison. Arguments: object base (obligatory): Top level object taken as 'Base' object mod1 (optional): Top level object taken as 'Mod1' object mod2 (optional): Top level object taken as 'Mod2' Return value: none

D.7.12.14

1252

ComMerge.GetCorrespondingObject

DIgSILENT PowerFactory 15, User Manual

D.7. POWERFACTORY COMMANDS object ComMerge.GetCorrespondingObject (object sourceObj, int target) Searches corresponding object for given object. Arguments: object sourceObj (obligatory): Object for which corresponding object is searched. int target(obligatory): 0: Get corresponding object from 'Base' 1: Get corresponding object from 'Mod1' 2: Get corresponding object from 'Mod2' Return value: Corresponding object or NULL

D.7.12.15

ComMerge.GetModification

int ComMerge.GetModification (object sourceObj [, int target]) Gets modification of corresponding objects between 'Base'and 'Mod1'or 'Mod2'. Arguments: object sourceObj (obligatory): Object from any source for which modification is searched. int target(optional): 1: Get modification from 'Base'to 'Mod1' 2: Get modification from 'Base'to 'Mod2' Return value: 0: 1: 2: 3: 4:

error, equal (no modofications), modified, added in Mod1/Mod2, removed in Mod1/Mod2

D.7.12.16

ComMerge.GetModificationResult

int ComMerge.GetModificationResult (object sourceObj) Gets modifications of compared objects between Mod1 and Mod2. Arguments: object sourceObj (obligatory): Object from any source for which modification is searched. Return value: 0: 1: 2: 3:

error, equal (no modofications), same modifications in 'Mod1'and 'Mod2'(no conflict) different modifications in 'Mod1'and 'Mod2'(conflict)

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APPENDIX D. DPL REFERENCE D.7.12.17

ComMerge.GetModifiedObjects

set ComMerge.GetModifiedObjects (int modType [, int modSource]) Gets all objects with a certain modification status from comparison. Arguments: int modType (obligatory): 0: get unmodified objects, 1: get modified objects, 2: get sdded objects, 3: get removed obejcts int ModSource (optional): 1: get objects with modification in 'Mod1' 2: get objects with modification in 'Mod 2' Return value: Set with objects found for given arguments. Unmodified, modified and added objects are always from given “modSource", removed objects are always from 'Base'.

D.7.13

ComLink Methods

SendData ReceiveData

D.7.13.1

Writes data of configured measurment objects to OPC tags (OPC only). Reads and processes values for all (in PF configured) items from OPC server (OPC only).

ComLink.SendData

int ComLink.SendData ([int force]) Writes data of configured measurment objects to OPC tags (OPC only). Arguments: int force (optional) : 0: (=default) send only data that have been changed and difference between old and new value is greater than configured deadband 1: forces (one-time) writing of all valueset.s (independet of previous value) Return value: Number of written items Example:

object Mea; set MeaSet; !Set temp status for all measurement objects MeaSet = AllRelevant('*.StaExt*'); 1254

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D.7. POWERFACTORY COMMANDS Mea = MeaSet.First(); while(Mea){ Mea.InitTmp(); Mea = MeaSet.Next(); } !initialization by forced sending all values Link.SendData(1);

D.7.13.2

ComLink.ReceiveData

int ComLink.ReceiveData ([int force]) Reads and processes values for all (in PF configured) items from OPC server (OPC only). Arguments: int force (optional) : 0: (=default) processes changed values received by PowerFactory via callback 1: forces (one-time) reading and processing of all values (independet of value changes) Return value: Number of read items

D.7.14

ComUcteexp Methods

D.7.14.1

ComUcteexp.BuildNodeNames

int ComUcteexp.BuildNodeNames () Builds the node names as used in UCTE export and makes them accessible via :UcteNodeName attribute. The node names will only be available as long as topology has not been changed. They must be re-build after any topology relevant modification. Arguments: none Return value: 0: on success 1: on error (e.g. load flow calculation failed) Example:

object com, term; set terms; int err; !get ComUcteexp from active study case com = GetCaseObject('ComUcteexp'); err = com.BuildNodeNames(); if (err > 0) { Error('Error in determination of UCTE node names'); DIgSILENT PowerFactory 15, User Manual

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APPENDIX D. DPL REFERENCE exit(); } !output node names terms = AllRelevant('*.'); for(term = terms.First(); term; term = terms.Next()) { printf('Terminal:%o UCTE Name: %s', term, term:UcteNodeName); }

D.8

Elements

Some object methods are specific for a type of object class. A result file object (ElmRes), for instance, has a “Write" method, which would not make sense for a load-flow command object. The general syntax for an object method is the same as that for a set method: object .

[OBJMETHOD] (arguments) ;

For Feeder Methods please refer to Section D.6.3 Feeder (SetFeeder) Methods. For Path Methods please refer to Section D.6.4 Path (SetPath) Methods.

D.8.1

Grid (ElmNet) Activate Deactivate CalculateInterchangeTo

D.8.1.1

Adds a grid to the active study case. Removes a grid from the active study case. Calculates the power flow from current grid to a connected grid.

ElmNet.Activate

int ElmNet.Activate () Adds a grid to the active study case. Can only be applied if there are is no currently active calculation. See also: ResetCalculation Arguments: none Return value: 0 on success, 1 on error.

D.8.1.2

ElmNet.Deactivate

int ElmNet.Deactivate () Removes a grid from the active study case.Can only be applied if there are is no currently active calculation.

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D.8. ELEMENTS See also: ResetCalculation Arguments: none Return value: 0 on success, 1 on error.

D.8.1.3

ElmNet.CalculateInterchangeTo

int ElmNet.CalculateInterchangeTo(object net) This function calculates the power flow from current grid to a connected grid. The values are stored in current grid in the following attributes (old values are overwritten): - Pinter: Active Power Flow - Qinter: Reactive Power Flow - ExportP: Export Active Power Flow - ExportQ: Export Reactive Power Flow - ImportP: Import Active Power Flow - ImportQ: Import Reactive Power Flow Arguments: object net: Connected grid Return value: - < 0: error - = 0: grids are not connected, no interchange exists - > 0: ok Example:

input:

object from; object to

int res; res = from.CalculateInterchangeTo(to); if (res > 0){ printf('Pinter: printf('Qinter: printf('ExportP: printf('ExportQ: printf('ImportP: printf('ImportQ: }

%d', %d', %d', %d', %d', %d',

from:c:Pinter); from:c:Qinter); from:c:ExportP); from:c:ExportQ); from:c:ImportP); from:c:ImportQ);

D.8.2

Asynchronous Machine (ElmAsm)

D.8.2.1

ElmAsm.GetAvailableGenPower

double ElmAsm.GetAvailableGenPower () DIgSILENT PowerFactory 15, User Manual

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APPENDIX D. DPL REFERENCE Returns the available power that can be dispatched from the generator, for the particular study time . For the case of conventional generators (no wind generation selected), the available power is equal to the nominal power specified. For wind generators, the available power will depend on the wind model specified: 1. No Wind Model: No available power 2.Stochastic Wind Model: Given the specified mean wind speed, the available power is calculated from the Power Curve. If the units of the Power Curve are in MW, the returned value is directly the available power. In the other hand, if the units are in PU, the returned value is multiplied by the nominal power of the generator to return the available power. 3. Time Series Characteristics of Active Power Contribution: The available power is the average of the power values (in MW) obtained from all the specified time characteristics for the current study time. 4. Time Series Characteristics of Wind Speed: The available power is calculated with the average of the power values (in MW) calculated for all the specified time characteristics. A power value for any time characteristic is calculated by obtaining the wind speed for the current study time, and then calculating the power from the specified Power Curve. If the units of the Power Curve are in MW, the returned value is directly the power value. In the other hand, if the units are in PU, the returned value is multiplied by the nominal power of the generator to return the power value. For motors, the available power is zero. Arguments: none Return value: Available generation power Example:

set objs; object obj; double totpwr, pwr; objs = AllRelevant('ElmAsm'); totpwr = 0; ! !

initialize cummulative generation

get cummulative generation

for (obj = objs.First(); obj; obj = objs.Next()){ pwr = obj.GetAvailableGenPower(); totpwr += pwr; } printf('Cummulative generation is %f', totpwr);

D.8.3

Double Fed Induction Machine (ElmAsmsc)

D.8.3.1

ElmAsmsc.GetAvailableGenPower

double ElmAsmsc.GetAvailableGenPower () Returns the available power that can be dispatched from the generator, for the particular study time . For the case of conventional generators (no wind generation selected), the available power is equal to the nominal power specified. 1258

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D.8. ELEMENTS For wind generators, the available power will depend on the wind model specified: 1. No Wind Model: No available power 2.Stochastic Wind Model: Given the specified mean wind speed, the available power is calculated from the Power Curve. If the units of the Power Curve are in MW, the returned value is directly the available power. In the other hand, if the units are in PU, the returned value is multiplied by the nominal power of the generator to return the available power. 3. Time Series Characteristics of Active Power Contribution: The available power is the average of the power values (in MW) obtained from all the specified time characteristics for the current study time. 4. Time Series Characteristics of Wind Speed: The available power is calculated with the average of the power values (in MW) calculated for all the specified time characteristics. A power value for any time characteristic is calculated by obtaining the wind speed for the current study time, and then calculating the power from the specified Power Curve. If the units of the Power Curve are in MW, the returned value is directly the power value. In the other hand, if the units are in PU, the returned value is multiplied by the nominal power of the generator to return the power value. For motors, the available power is zero. Arguments: none Return value: Available generation power Example:

set objs; object obj; double totpwr, pwr; objs = AllRelevant('ElmAsmsc'); totpwr = 0; ! !

initialize cummulative generation

get cummulative generation

for (obj = objs.First(); obj; obj = objs.Next()){ pwr = obj.GetAvailableGenPower(); totpwr += pwr; } printf('Cummulative generation is %f', totpwr);

D.8.4

Feeder (ElmFeeder) GetAll GetBuses GetBranches GetNodesBranches GetObjs

D.8.4.1

Returns all objects in this feeder. Returns all buses in this feeder. Returns all branch elements in this feeder. Returns all buses and branches in this feeder. Returns all objects of class ClassName in this feeder.

ElmFeeder.GetAll

set ElmFeeder.GetAll ([int iNested]) Returns a set with all objects belonging to this feeder. DIgSILENT PowerFactory 15, User Manual

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APPENDIX D. DPL REFERENCE Arguments: int iNested (optional) : In case of nested feeders, all elements will be returned when iNested=1, otherwise only the objects up to the next feeder will be returned. Return value: The set of feeder objects. Example:

set aAll,aFeeders; object pPrj,pFeeder,pObj; ! output elements in the feeders pPrj = GetActiveProject(); if (pPrj) { aFeeders = pPrj.GetContents('*.ElmFeeder',1); aFeeders.SortToVar(0,'loc_name'); for (pFeeder=aFeeders.First(); pFeeder; pFeeder=aFeeders.Next()){ printf('Elements in feeder %s',pFeeder:loc_name); aAll = pFeeder.GetAll(1); for (pObj=aAll.First(); pObj; pObj=aAll.Next()) { printf('%s\\%s',pObj:r:fold_id:loc_name,pObj:loc_name); } } } See also General Functions and Methods Data Container

D.8.4.2

ElmFeeder.GetBuses

set ElmFeeder.GetBuses ([int iNested]) Returns a set with all buses belonging to this feeder. Arguments: int iNested (optional) : In case of nested feeders, all elements will be returned when iNested=1, otherwise only the objects up to the next feeder will be returned. Return value: The set of bus elements in feeder. Example:

set aNodes,aFeeders; object pPrj,pFeeder,pObj; ! output elements in the feeders pPrj = GetActiveProject(); if (pPrj) { aFeeders = pPrj.GetContents('*.ElmFeeder',1); aFeeders.SortToVar(0,'loc_name');

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D.8. ELEMENTS for (pFeeder=aFeeders.First(); pFeeder; pFeeder=aFeeders.Next()){ printf('Buses in feeder %s',pFeeder:loc_name); aNodes = pFeeder.Getbuses(1); for (pObj=aNodes.First(); pObj; pObj=aNodes.Next()) { printf('%s\\%s',pObj:r:fold_id:loc_name,pObj:loc_name); } } } See also General Functions and Methods Data Container

D.8.4.3

ElmFeeder.GetBranches

set ElmFeeder.GetBranches ([int iNested]) Returns a set with all branch elements belonging to this feeder. Arguments: int iNested (optional) : In case of nested feeders, all elements will be returned when iNested=1, otherwise only the objects up to the next feeder will be returned. Return value: The set of branch elements in feeder. Example:

set aBranches,aFeeders; object pPrj,pFeeder,pObj; ! output elements in the feeders pPrj = GetActiveProject(); if (pPrj) { aFeeders = pPrj.GetContents('*.ElmFeeder',1); aFeeders.SortToVar(0,'loc_name'); for (pFeeder=aFeeders.First(); pFeeder; pFeeder=aFeeders.Next()){ printf('Branches in feeder %s',pFeeder:loc_name); aBranches = pFeeder.GetBranches(1); for (pObj=aBranches.First(); pObj; pObj=aBranches.Next()){ printf('%s\\%s',pObj:r:fold_id:loc_name,pObj:loc_name); } } } See also General Functions and Methods Data Container

D.8.4.4

ElmFeeder.GetNodesBranches

set ElmFeeder.GetNodesBranches ([int iNested]) DIgSILENT PowerFactory 15, User Manual

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APPENDIX D. DPL REFERENCE Returns a set with all buses and branches belonging to this feeder. Arguments: int iNested (optional) : In case of nested feeders, all elements will be returned when iNested=1, otherwise only the objects up to the next feeder will be returned. Return value: The set of bus and branch elements in feeder. Example:

set aAll,aFeeders; object pPrj,pFeeder,pObj; ! output elements in the feeders pPrj = GetActiveProject(); if (pPrj) { aFeeders = pPrj.GetContents('*.ElmFeeder',1); aFeeders.SortToVar(0,'loc_name'); for (pFeeder=aFeeders.First(); pFeeder; pFeeder=aFeeders.Next()){ printf('Branches and Nodes in feeder %s',pFeeder:loc_name); aAll = pFeeder.GetNodesBranches(1); for (pObj=aAll.First(); pObj; pObj=aAll.Next()) { printf('%s\\%s',pObj:r:fold_id:loc_name,pObj:loc_name); } } }

D.8.4.5

ElmFeeder.GetObjs

set ElmFeeder.GetObjs (string ClassName [, int iNested]) Returns a set with all objects of class 'ClassName''which belong to this feeder. Arguments: int iNested (optional) : In case of nested feeders, all elements will be returned when iNested=1, otherwise only the objects up to the next feeder will be returned. Return value: The set of feeder objects. Example:

set aAll,aFeeders; object pPrj,pFeeder,pObj; ! output elements in the feeders pPrj = GetActiveProject(); if (pPrj) { aFeeders = pPrj.GetContents('*.ElmFeeder',1); aFeeders.SortToVar(0,'loc_name'); for (pFeeder=aFeeders.First(); pFeeder; pFeeder=aFeeders.Next()){ printf('Cubicles in feeder %s',pFeeder:loc_name); aAll = pFeeder.GetObjs('StaCubic'); for (pObj=aAll.First(); pObj; pObj=aAll.Next()) { 1262

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D.8. ELEMENTS printf('%s\\%s',pObj:r:fold_id:loc_name,pObj:loc_name); } } }

D.8.5

Boundary (ElmBoundary)

D.8.5.1

ElmBoundary.IsSplitting

int ElmBoundary.IsSplitting (set notsplittingCubicles) Checks if the boundary splits the network into two regions. A boundary is called splitting, if and only if, for each boundary cubicle, the adjacent terminal and the adjacent branch component belong to different sides of the boundary. Arguments: set notsplittingCubicles (obligatory) : All cubicles that prevent the boundary from being splitting are filled into this set. Return value: none Example:

set cubs; object cub; int res; res = boundary.IsSplitting(cubs); if (res){ printf('Boundary is splitting'); }else{ printf('Boundary is not splitting because of'); for (cub = cubs.First(); cub; cub = cubs.Next()){ cub.ShowFullName(); } }

D.8.5.2

ElmBoundary.AddCubicle

int ElmBoundary.AddCubicle (object cubicle, int orientation) This method adds a given cubicle with given orientation to an existing boundary. The cubicle is only added, if it is not yet contained (with same orientation). Return value: 0: cubicle was successfully added 1: cubicle was not added because it is already contained (including given orientation)

D.8.5.3

ElmBoundary.Clear

void ElmBoundary.Clear() This method removes all boundary cubicles from an existing boundary. DIgSILENT PowerFactory 15, User Manual

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APPENDIX D. DPL REFERENCE D.8.5.4

ElmBoundary.GetInterior

set ElmBoundary.GetInterior() Returns a all elements that are contained in the interior region of the boundary.

D.8.6

Cubicles (StaCubic) AddBreaker RemoveBreaker GetConnectedMajorNodes

GetAll

D.8.6.1

creates a new StaSwitch inside the cubicle. This function deletes all StaSwitch objects stored in the StaCubic object. Returns all major nodes that can be reached starting a topology search from the cubicle in direction of the referenced branch element. Returns a set of network components that are collected by a topological traversal starting at the cubicle (StaCubic) where the function is called.

StaCubic.AddBreaker

object StaCubic.AddBreaker () This function creates a new StaSwitch inside the cubicle it was called on. A new StaSwitch is only created in case that the StaCubic object does not contain a StaSwitch object yet. A StaSwitch object is created by this function is always of usage 'circuit-breaker'and its state is 'closed'. Arguments: none Return value: • StaSwitch object in case a new switch was created • null if no object was created. This means a StaSwitch object does already exist. Example:

set cubics; object cubic, swt; cubics = AllRelevant('*.StaCubic'); !create StaSwitches in all cubicles that do not contain a switch yet for(cubic = cubics.First(); cubic; cubic = cubics.Next()) { swt = cubic.AddBreaker(); if (swt) { swt.ShowFullName(); } }

D.8.6.2

StaCubic.RemoveBreaker

object StaCubic.RemoveBreaker () 1264

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D.8. ELEMENTS This function deletes all StaSwitch objects stored in the StaCubic object it was called on. Example:

set cubics; object cubic; cubics = AllRelevant('*.StaCubic'); !delete StaSwitches from all cubicles for(cubic = cubics.First(); cubic; cubic = cubics.Next()) { cubic.RemoveBreaker(); }

D.8.6.3

StaCubic.GetConnectedMajorNodes

set StaCubic.GetConnectedMajorNodes () This function returns all major nodes that can be reached starting a topology search from the cubicle in direction of the referenced branch element. The search stops in each direction when a major node was found (so only the first major node in every direction is collected). First, the internally executed search does not pass any open switch. Only if this search does not find any major node, a second is executed ignoring all switches. Addition: If no major node has been found all reached “pseudo" major nodes are returned. A pseudo major node is a terminal of priority 1000. Terminals of that priority are not considered to be major nodes. They are only used as a replacement for real major nodes if no real major node could be found. Arguments: none Return value: A set of all major nodes that can be reached starting a topology search from the cubicle in direction of the referenced branch element. Example:

object substat, cub, obj; set s, buses, cubicles, elements, allCubicles, terms; int index, return; string name; !displays all connected major nodes for all connection cubicles !of all substations s = AllRelevant('*.ElmSubstat'); for (substat = s.First(); substat; substat = s.Next()){ allCubicles.Clear(); index = 0; return = 0; while (return 1){ return = substat.GetSplit(index, buses, cubicles, elements); if (return = 0){

DIgSILENT PowerFactory 15, User Manual

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APPENDIX D. DPL REFERENCE allCubicles.Add(cubicles); } index = index +1; } for(cub = allCubicles.First(); cub; cub = allCubicles.Next()){ name = cub.GetFullName(0); printf('\nMajor Nodes cubicle %s is connected to:', name); terms = cub.GetConnectedMajorNodes(); for (obj = terms.First(); obj; obj = terms.Next()){ obj.ShowFullName(); } } }

D.8.6.4

StaCubic.GetAll

set StaCubic.GetAll ([int direction, int ignoreOpenSwitches]) This function returns a set of network components that are collected by a topological traversal starting at the cubicle (StaCubic) where the function is called. Arguments: int direction (optional): Specifies the direction in which the network topology is traversed. 1: Traversal to the branch element -1: Traversal to the terminal element. If this parameter is omitted, the default of '1'(direction to the branch element) is used. int ignoreOpenSwitches (optional): Determines whether to pass open switches or to stop at them. 0: The traversal stops in a direction if an open switch is reached. 1: Ignore all switch statuses and pass every switch. The default, if omitted, is '0'. Return value: A set of network components that are collected by a topological traversal starting at the cubicle (StaCubic) where the function is called. Example:

For a defined variable “cubic" pointing to a cubicle in a net set s; object o; s = cubic.GetAll(); !same as cubic.GetAll(1, 0); s.MarkInGraphics(); for (o = s.First(); o; o = s.Next()){ o.ShowFullName(); } Pass open switches: s = cubic.GetAll(1, 1); Walk in opposite direction: s = cubic.GetAll(-1); !equivalent to cubic.GetAll(-1, 0);

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D.8. ELEMENTS Walk in opposite direction and ignore switch states: s = cubic.GetAll(-1, 1);

D.8.7

Composite Model (ElmComp)

D.8.7.1

ElmComp.Slotupd

void ElmComp.Slotupd () Performs a slot update for the composite model, to automatically select available models for the slots. Arguments: none Return value: none See also General Functions and Methods Data Container

D.8.8

Breaker/Switch (ElmCoup) Close Open IsOpen IsClosed IsBreaker GetRemoteBreakers

D.8.8.1

Closes the bus coupler. Opens the bus coupler. Returns 1 when the coupler is open. Returns 1 when the coupler is closed. Returns 1 if the switch is a circuit-breaker. Finds the remote circuit breakers and local buses.

ElmCoup.Close

int ElmCoup.Close () Closes the buscoupler. Arguments: none Return value: 0 on success Example: The following example gathers all open couplers before closing them. int opn; set S, So; DIgSILENT PowerFactory 15, User Manual

1267

APPENDIX D. DPL REFERENCE object O; S = Couplers.AllElm(); O = S.First(); while (O) { opn = O.IsOpen(); if (opn) { O.Close(); So.Add(O); }; }

D.8.8.2

ElmCoup.Open

int ElmCoup.Open () Opens the buscoupler. Arguments: none Return value: 0 on success Example: The following example gathers all closed couplers before opening them. int cl; set S, Sc; object O; S = Couplers.AllElm(); O = S.First(); while (O) { cl = O.IsClosed(); if (opn) { O.Open(); Sc.Add(O); }; }

D.8.8.3

ElmCoup.IsOpen

int ElmCoup.IsOpen () Returns 1 when the coupler is open. Arguments: none Return value: 1 when open, 0 when closed Example: 1268

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D.8. ELEMENTS

See ElmCoup.Close for an example

D.8.8.4

ElmCoup.IsClosed

int ElmCoup.IsClosed () Returns 1 when the coupler is closed. Arguments: none Return value: 1 when closed, 0 when open Example: See ElmCoup.Open for an example

D.8.8.5

ElmCoup.IsBreaker

set ElmCoup.IsBreaker () This function returns 1 if the switch is a circuit-breaker. Arguments: none Return value: 1: switch (ElmCoup) is a circuit-breaker, 0: switch (ElmCoup) is not a circuit-breaker

D.8.8.6

ElmCoup.GetRemoteBreakers

void ElmCoup.GetRemoteBreakers (int CbStatus, set pBreakers, set pBusbars) This function finds the remote circuit breakers and local buses. A toposearch is started from this breaker in all directions, stopping at the breakers (ElmCoup::aUsage = cbk) which are connected with the target breaker by non-reduciable components (see IsReducible()) and all equivalent busbars (::iUsage == 0 and only connected by reducible components). If search stops at a breaker that is in given breaker state (CbStatus), it is added to the pBreakers collection. All busbars at which the search stops are added to the pBusbars collection. Arguments: int CbStatus (obligatory) : The status of remote circuit breakers which will be searched. -1: Return all remote circuit breakers 1: Return all closed remoted circuit breakers 0: Return all opened remoted circuit breakers set pBreakers (obligatory) : The list of the remoted circuit breakers DIgSILENT PowerFactory 15, User Manual

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APPENDIX D. DPL REFERENCE set pBusbars (obligatory) : The list of the local bus bars Return value: none Example: The following example gathers all closed couplers before opening them. object targetCB; set RECBList; set FocusBusList object oRemCB;

sRet = targetCB.GetRemoteBreakers(1, RECBList, FocusBusList); Info('The remoted circuit breakers of %o are as follows:\n', targetCB); for (oRemCB = RECBList.First();oRemCB; oRemCB = RECBList.Next()) { oRemCB.ShowFullName(); }

D.8.9

Line (ElmLne) HasRoutes HasRoutesOrSec GetType IsCable IsNetCoupling SetCorr CreateFeederWithRoutes SetDetailed GetZ0m GetZ1m GetY0m GetY1m FitParams

D.8.9.1

Checks if the line is subdivided into routes. Checks if the line is subdivided into routes or sections. Returns the line type object. Checks if this is a cable. Checks if the line connects two grids. Sets the correction factor of the line. Splits the line in 2 routes. Prevents the automatically reduction of a line. Returns the zero-sequence mutual coupling impedance (R0m, Z0m). Returns the positive-sequence mutual coupling impedance (R1m, Z1m). Returns the zero-sequence mutual coupling admittance (G0m, B0m). Returns the positive-sequence mutual coupling admittance (G1m, B1m). Calculates distributed parameters for lines.

ElmLne.HasRoutes

int ElmLne.HasRoutes () Checks if the line is subdivided into routes. Arguments: none Return value: 1270

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D.8. ELEMENTS 0 when the line is a single line, 1 when it is subdivided into routes. Example: The following example reports all lines with routes. set S; object O; int i; S = AllRelevant(); O = S.Firstmatch('ElmLne'); while (O) { i = O.HasRoutes(); if (i) O.ShowFullName(); O = S.Nextmatch(); }

D.8.9.2

ElmLne.HasRoutesOrSec

int ElmLne.HasRoutesOrSec () Checks if the line is subdivided into routes or sections. Arguments: none Return value: 0 when the line is a single line, 1 when it is subdivided into routes, 2 when into sections. Example: The following example reports all lines with sections. set S; object O; int i; S = AllRelevant(); O = S.Firstmatch('ElmLne'); while (O) { i = O.HasRoutesOrSec(); if (i=2) O.ShowFullName(); O = S.Nextmatch(); }

D.8.9.3

ElmLne.GetType

int ElmLne.GetType () Returns the line type object. Arguments: none

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APPENDIX D. DPL REFERENCE Return value: The TypLne object Example: The following example reports all 'untyped'lines set S; object O, T; S = AllRelevant(); O = S.Firstmatch('ElmLne'); while (O) { T = O.GetType(); if (T=0) { O.ShowFullName(); } O = S.Nextmatch(); }

D.8.9.4

ElmLne.IsCable

int ElmLne.IsCable () Checks if this is a cable. Arguments: none Return value: 1 when the line is a cable, otherwise 0. Example: The following example reports the loading of all cables. set S; object O; int i; S = AllRelevant(); O = S.Firstmatch('ElmLne'); while (O) { i = O.IsCable(); if (i) { Write('# : #.## $N, @ACC(1):loc_name, @ACC(1):c:loading, O); } O = S.Nextmatch(); }

D.8.9.5

ElmLne.IsNetCoupling

int ElmLne.IsNetCoupling () Checks if the line connects two grids. 1272

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D.8. ELEMENTS Arguments: none Return value: 1 when the line is a coupler, otherwise 0. Example: The following example reports all the loading of all couplers set S; object O; int i; S = AllRelevant(); O = S.Firstmatch('ElmLne'); while (O) { i = O.IsNetCoupling(); if (i) { Write('# :#.## $N, @ACC(1):loc_name, @ACC(1):c:loading,O); } O = S.Nextmatch(); }

D.8.9.6

ElmLne.SetCorr

int ElmLne.SetCorr () Sets the correction factor of the line, according to IEC364-5-523. Arguments: none Return value: 0 on success, 1 on error; Example: The following example sets a correction factor. BuriedLine.SetCorr();

D.8.9.7

ElmLne.CreateFeederWithRoutes

int ElmLne.CreateFeederWithRoutes (double dis,double rem,object O [, int sw0, int sw1]) Creates a new feeder in the line by splitting the line in 2 routes and inserting a terminal. Arguments: double dis (obligatory) : double rem (obligatory) :

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APPENDIX D. DPL REFERENCE object O (obligatory) : A branch object that is to be connected at the inserted terminal. int sw0 (optional) : when true, a switch is inserted on the one side int sw1 (optional) : when true, a switch is inserted on the other side Return value: 0 on success, 1 on error;

D.8.9.8

ElmLne.SetDetailed

void ElmLne.SetDetailed () The function can be used to prevent the automatically reduction of a line e.g. if the line is a line dropper (length = 0). The function should be called when no calculation method is valid (before first load flow). The internal flag is automatically reset after the first calculation is executed. Arguments: none Return value: none Example:

! !

Line is an ElmLne object, length = 0 (=> line dropper)

ResetCalculation(); ! Line.SetDetailed(); ! Ldf.Execute(); ! ! line is not reduced

be sure that no calculation is valid set detailed flag for line calculation load flow

ResetCalculation(); ! reset calculation Ldf.Execute(); ! calculate load flow ! line is now reduced again

D.8.9.9

ElmLne.GetZ0m

int ElmLne.GetZ0m (object Lne2, double R0m,double X0m) The function return the zero-sequence mutual coupling impedance (R0m, X0m) in Ohm of the line and line: Lne2. When Lne2 = line, the function returns the zero-sequence self impedance. Arguments: none Return value: 0: ok, 1: error, e.g. if line is not part of a line couplings object (ElmTow)

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D.8. ELEMENTS D.8.9.10

ElmLne.GetZ1m

int ElmLne.GetZ1m (object Lne2, double R1m,double X1m) The function return the positive-sequence mutual coupling impedance (R1m, X1m) in Ohm of the line and line: Lne2. When Lne2 = line, the function returns the positive-sequence self impedance. Arguments: none Return value: 0: ok, 1: error, e.g. if line is not part of a line couplings object (ElmTow)

D.8.9.11

ElmLne.GetY0m

int ElmLne.GetY0m (object Lne2, double G0m,double B0m) The function returns the zero-sequence mutual coupling admittance (G0m, B0m) in 𝑆 of the line and line: Lne2. When Lne2 = line, the function returns the zero-sequence self admittance. Arguments: none Return value: 0: ok, 1: error, e.g. if line is not part of a line couplings object (ElmTow)

D.8.9.12

ElmLne.GetY1m

int ElmLne.GetY1m (object Lne2, double G1m,double B1m) The function returns the zero-sequence mutual coupling admittance (G1m, B1m) in 𝑆 of the line and line: Lne2. When Lne2 = line, the function returns the positive-sequence self admittance. Arguments: none Return value: 0: ok, 1: error, e.g. if line is not part of a line couplings object (ElmTow)

D.8.9.13

ElmLne.FitParams

int ElmLne.FitParams () Calculates distributed parameters for lines. Calculates distributed parameters for line elements. Whether this function calculates constant parameters or frequency dependent parameters depends on the user setting of the parameter 'i_model'in the ElmLne dialogue. The settings are as follows: i_model=0: constant parameters; i_model=1: frequency dependent parameters.

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APPENDIX D. DPL REFERENCE Arguments: none Return value: 0: on success, 1: on error Example:

object oLine; set sLines; int err; sLines = AllRelevant('*.ElmLne'); oLine = sLines.First(); err = oLine.FitParams(); if (err) { Error('Could not calculate line parameters for %s.', oLine); exit(); }

D.8.10

Result Object (ElmRes)

AddVars Clear Draw Flush GetObj GetResData Init LoadResData ReleaseResData ResIndex ResFirstValidObject ResFirstValidObjectVar ResFirstValidVar ResNextValidObject ResNextValidObjectVar ResNextValidVar ResNval ResNvars SetAsDefault Write WriteDraw

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Adds to the list of monitored variables. Clears the result object. Updates all relevant plots. Copies all data buffered in memory to the disk. Returns objects used in the result file. Returns a value from a certain result curve. Initializes the result object. Loads the data of a result file in memory. Releases the result file data loaded to memory. Returns column number of variable in result object. Gets the index of the column for the first valid object in the given line. Gets the index of the column for the first valid variable of the current object in the current line. Gets the index of the column for the first valid variable in the given line. Gets the index of the column for the next valid object in the current line. Gets the index of the column for the next valid variable of the current object in the current line. Gets the index of the column for the next valid variable in the given line. Returns number of values stored in certain result curve. Returns the number of variables (columns) in result file. Sets this as default results. Writes the current results. Writes results and updates all plots.

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D.8. ELEMENTS D.8.10.1

ElmRes.AddVars

void ElmRes.AddVars (object O, string v1 [,string v2,...]) Adds variables to the list of monitored variables for the Result object. Arguments: object O (obligatory) : an object. string v1 (obligatory) : variable name for object O. string v2..v9 (optional) : optional further variables names for object O. Return value: none Example:

object Res; Res = MyResults(); Res.AddVars(MyLine,'m:Ikss:busshc','m:I:busshc');

D.8.10.2

ElmRes.Clear

int ElmRes.Clear () Clears the result object. Arguments: none Return value: 0 on success Example: The following example clears the result object. Res.Clear();

D.8.10.3

ElmRes.Draw

int ElmRes.Draw () Updates all plots that display values from the result object. Arguments: none Return value: 0 on success DIgSILENT PowerFactory 15, User Manual

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APPENDIX D. DPL REFERENCE Example: The following example updates the graphics every 10 steps to save time and yet follow the results while calculating double i,n; Ld:pini = LoadMin; i = 1; n = 0; while (Ld:pini9) { Res.Write(); n = 0; } }

D.8.10.4

ElmRes.Flush

void ElmRes.Flush () This function is required in DPL scripts which perform both file writing and reading operations. While writing to a results object (ElmRes), a small portion of this data is buffered in memory. This is required for performance reasons. Therefore, all data must be written to the disk before attemting to read the file. 'Flush'copies all data buffered in memory to the disk. After calling 'Flush'all data is available to be read from the file. Arguments: none Return value: none Example: The following example writes a result object and prints the data written to the file. The DPL command contains to variables on the advanced options page: double x double y

x-value y-value

These variables were selected in the variable definitions inside the result object which itself is stored in the DPL command. The DPL script code is as follows: int iNotOk, iX,iY,iRow; double dX,dY; ! write the data for (x=-16; x= limit2 set objects (obligatory) : Valid objects Return value: >=0: column index = 80% iCol = ResFirstValidObject(oRes, iRow, 'ElmLne,ElmSym', 'c:loading', 80, 4);

D.8.10.12

ElmRes.ResFirstValidObjectVar

int ResFirstValidObjectVar (object resultFile [, string variableNames]) Gets the index of the column for the next valid variable of the current object in the current line. Starts at the internal iterator of the given result file and sets it to the found position. Arguments: object resultFile (obligatory) : Result file string variableNames (optional) : Comma separated list of valid variable names. The next column with one of the given variables is searched. If not set all variables are considered as valid (default). Return value: >=0: column index =0: column index = limit double limit2 (optional) : Second limiting value for the variable. int limitOperator2 (optional) : Operator for checking the second limiting value: 0: first AND second criterion must match, 0: all values are valid (default) 1/-1: valid values must be < limit2 2/-2: valid values must be limit2 4/-4: valid values must be >= limit2 set objects (obligatory) : Valid objects Return value: >=0: column index = 80% iCol = ResNextValidObject(oRes, 'ElmLne,ElmSym', 'c:loading', 80, 4);

D.8.10.15

ElmRes.ResNextValidObjectVar

int ResNextValidObjectVar (object resultFile, int row [, string variableNames]) Gets the index of the column for the next valid variable of the current object in the current line. Starts at the internal iterator of the given result file and sets it to the found position.

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APPENDIX D. DPL REFERENCE Arguments: object resultFile (obligatory) : Result file int row (obligatory) : Result file row string variableNames (optional) : Comma separated list of valid variable names. The next column with one of the given variables is searched. If not set all variables are considered as valid (default). Return value: >=0: column index =0: column index