MiCOM IEDs for Process Bus_Experts 2012

MiCOM IEDs For Process Bus Applications

April 2009 GRID

Experts Training 2012 Stafford, United Kingdom

Scope

Digital Substations & Process Bus Overview

Page 3

MiCOM IEDs for Process Bus

Page 21

Px4x -9-2LE Interface Features

Page 31

Process Bus Architectures

Page 47

Testing, Conclusion

Page 60

Reference Digital SS Architecture across Grid Grid Control Rooms

SG APPS

Other substations

Digital SS Components Integrated Substation Automation System with

WAN

SCS HMI

SG APPS

CMS

PDC

1. Substation Control System (SCS) 2. Condition Monitoring System (CMS) 3. Smart Grid Applications (SG APPS – Cyber, Intrusion, Wide Area Management) 4. Substation Phasor Data Concentrator

Proxy Switches Multiple Ethernet IEC61850.8-1 Station Bus C37.118 Phasor Data

sPDC

BCU Multiple Ethernet IEC61850.9-2 & IEC61850.8-1 Process Bus

WACU

Prot. Px40

AMU

DMU

CMU

DRUs

Primary Eqpt with embedded sensors for Condition Monitoring

Presentation title - 01/01/2010 - P 3

Several IEDs 1. Protection / Measurement with 9-2 interface 2. Bay Controller Unit (BCU) 3. Condition Monitoring Unit (CMU) 4. Switches & Telecom 5. Proxy Server 6. Merging Units (AMU, DMU, NMU – for NCIT) 7. Wide Area Control Unit (WACU) 8. Power Quality /Disturbance Record Unit (DRU) 9. Energy Meters

IEC 61850 Process Bus Process Bus Elements
Ethernet Network, 100 Mb/s
IEC 61850-9-2 LE for Sampled Values “SV”  Current measurement (CT)  Voltage measurement (VT)


IEC 61850-8-1 GOOSE Service    

Status position of Circuit Breaker / Switches (CB) Trip signals from protections to CBs (Trip) Commands from Control Systems (Open/Close) Others (monitoring status reports, health, settings…)


Time synchronisation  Microsec accuracy required

IEC 61850 Process Bus Logical View Of SA Station Level

9 Function B

Function A

61850-8-1 1 Bay Level

6

HV Equipment

1

3

Protection

4

Technical Services

7

8 Control

5

61850-9-2 61850-8-1

Bay Level

6 3

Protection

4 HV Equipment

Control

5

IEC 61850 -9-2 Overview
Sampled Value Transmission  Unidirectional link (MU to IED)  Physical layer : Optic fibre (copper optional)  Data Link layer : Ethernet 100 Mbit/s
Application Layer : IEC 61850-9-2 “Light Edition” guideline to aid

implementation and interoperability     

Sampling rate : 80 or 256 samples per cycle Neutral current and/or voltage may be measured, or derived Sampled values are multicast on the LAN Defines Logical Device “MU” Synchronising of sampling

IEC 61850 -9-2 Overview
IEC 61850-9-2LE Sampled Values  Each SV message carries 4 voltages + 4 currents  Primary values, quality info  Current : 1mA to 2.14 MA, Voltage : 10mV to 21.4 MV (I1a, I1b, I1c, I1n, V1a, V1b, V1c, V1n)

Protection Bay 1

4V; 4I 4V; 4I

Protection Bay 2

MU-L1 MU-L2 (I2a, I2b, I2c, I2n, V2a, V2b, V2c, V2n)

IEC 61850 -9-2 Overview -9-2LE Sampled Value Frame

Ia x 1000 32 bit Int

Ia Quality 32 bits

Ib x 1000 Ib Quality 32 bit Int 32 bits

Ic x 1000 32 bit Int

Ic Quality 32 bits

In x 1000 In Quality 32 bit Int 32 bits

Va x 1000 Va Quality Vb x 1000 Vb Quality Vc x 1000 Vc Quality Vn x 1000 Vn Quality 32 bit Int 32 bits 32 bit Int 32 bits 32 bit Int 32 bits 32 bit Int 32 bits


SV frames are multicast  MAC Address range: 01-0C-CD-04-00-00 to 01-0C-CD-04-1F-FF input on Merging Units  Note the frame overhead : 24 bytes of ‘raw data’ (per 3-phase voltage and current) in about 125 byte Ethernet frame

HQ_IEC 61850 Process Bus_06/2011

IEC 61850 Process Bus Merging Unit – Typical Naming
AMU : Analogue Merging Unit  Interface with conventional instrument transformers


DMU : Digital Merging Unit  Interface with CB / isolators / earth switches


CMU : Condition Monitoring Merging Unit  DMU with condition monitoring features


NMU : Numerical Merging Unit  Interface with digital instrument transformers

IEC 61850 Process Bus Conventional Bay Protection & Control – Example  Main 1, Main 2, BCU  Individual CT cores per IED  Independent tripping paths for Main 1 and Main 2 typically

Status & Trips

CB

Presentation title - 01/01/2010 - P 10

IEC 61850 Process Bus Digital Bay Protection & Control – Example

Presentation title - 01/01/2010 - P 11

-8-1 PRP

DMU#2 -8-1 PRP

-9-2LE

DMU#1

AMU #3 -9-2LE

AMU #2 -9-2LE

AMU #1

   

Main 1, Main 2, BCU AMU, DMU Ethernet links and switches Time synch eqpt

Process Bus (conceptual)

IEC 61850 -9-2 Overview AMU - Sampling Synchronisation
Sampling across multiple analogue MUs may need to be

synchronised  Protection functions/algorithms require all input quantities to be supplied in ‘real time’  Relay inputs may be from multiple MUs o Substation layout o Customer specifications  Similar to synchrophasor measurements Eg: Distance Protection (Voltage & Current)  Both voltage & current could be supplied by one MU – synchronisation integral to the MU  Voltage from MU1 and current from MU2 - synchronisation requires common time reference input to MUs HQ_IEC 61850 Process Bus_06/2011

IEC 61850 -9-2 Overview 1 ms delay

V˂0

V˂-18 2.5 ms delay

I˂-36

I˂-81

→ SV frames from different MU may have uneven delays → Relay measurements will be incorrect unless the SV frames are time-aligned Presentation title - 01/01/2010 - P 13

IEC 61850 -9-2 Overview AMU - Sampling Synchronisation
Techniques  1 PPS input on Merging Units  Merging Units with capability for IEEE 1588 synchronisation


Sampled Value frames carry synchronisation info  Time tags (count) relative to the start of the ‘sec’  Identifier for sync source – Global, Local or No Sync

Sample Count 0 – 3999 at 50 Hz 0 – 4799 at 60 Hz Counter resets every sec when a time sync signal is received

Indicates if the SV frame is synchronised

IEC 61850 -9-2 Overview Relay - Sampled Values Alignment
Time alignment of SV frames is necessary, and ensures correct operation of protection functions dependent on multiple MU’s  The number of MU’s may change depending on site requirements and customer preferences
Delays arise from  Merging Units, due to their processing  Network, depending on its configuration and switches
Delays have a direct impact on the operating time of the scheme

 Time tags (count) relative to the start of the ‘sec’  Identifier for sync source – Global, Local or No Sync

Presentation title - 01/01/2010 - P 15

IEC 61850 -9-2 Overview AMU - Sampling Synchronisation


Sampling Synchronisation Accuracy   

Time source accuracy +/- 1µs Sampling across multiple MUs synchronised to within +/- 4µs MU should be capable of compensating network delays > 2µs

MiCOM P594

IEC 61850 -9-2 Overview AMU - Sampling Synchronisation


1 Pulse Per Sec (1PPS) Signal     

Transmitted by fibre as medium Rise and fall time < 20ns Clock source : Typically based on GPS Global 1PPS: 1PPS source is synced to GPS, pulse width between 5µs and 500 ms Local 1PPS : 1PPS source running on internal clock, pulse width between 0.9µs and 1.1µs 1PPS

P594

Merging Unit

IEC 61850 -9-2 Overview AMU - Sampling Synchronisation


Sync Flags in SV Frame    

Carried by the field smpSync Global 1PPS: Ideal, no impact on protection functions Local 1PPS : Some protections may have to be blocked eg: Feeder differential No Sync : No 1PPS at AMU, running on AMU internal clock. o Protections dependent on multiple MUs for data may be blocked, eg: distance protection with two CT inputs) o MU said to be in ‘Holdover Mode’ -9-2LE SAV

Merging Unit

IEC 61850 -9-2 Overview AMU - Sampling Synchronisation


IEEE 1588 Basics 

It is a high precision time synchronization (