Substation Automation (OSAS)

OPEN SUBSTATION AUTOMATION SYSTEM (OSAS)

Prepared By: Shamsheer.T Electrical Engineer Energy & Power Contracting Co. Ltd. Al khobar-KSA

Contents 

Introduction

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Substation Automation Objective

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Traditional SCDA System

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OSAS Concept & Components

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OSAS Overview & Architecture

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OSAS Applications

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OSAS Implementation

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Merits of OSAS

Introduction 

Substation automation was introduced over the last 30years

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More than 4000 systems have been installed word wide.

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This was based on proprietary serial communication with conventional copper wiring.

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With advent of IEC61850 there is a comprehensive global standard for all communication needs in the sub station being introduced now.

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IEC 61850

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Very big commercial impact “saving “saving millions of dollars”

Substation Automation Objective of automation: automation : 

Control

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Monitor &

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Protect ion

substation equipment must be monitored and controlled for increased reliability, reduced fault restoration times, and balanced electrical demand with available generation Protects high voltage equipments from faults, disturbances, and overloading on the power grid, and optimizes power to utility customers.

Traditional SCADA System Components: Master station, RTUs, IEDs, transducers & sensors. Master Station: Provides the primary operator interface and manages overall system functions, collecting and analyzing data from RTUs, as well as initiating control actions. RTUs: Detects timestamps, and and logs set-point and and I/O events. IEDs, transducers & sensors: measure power, energy, voltage, current, etc.

Traditional SCADA System

Traditional SCADA System Drawback: 

Expensive

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Master station hardware & software are designed using expensive proprietary systems.

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Additional investment for training and maintenance

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As the RTU is the central device, many features are to be added to improve reliability

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RTU enhancements are very expensive

Open Substation Automation System Concept System comprised of Web enabled software and intelligent IEDs & control devices. 

Monitor, record calculate & analyze hundreds of data points in real time

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Provide status monitoring

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Automatic control, alarm and advanced power quality analysis with OSAS IED.

Open System: A computer system

Open Substation Automation System (OSAS) Components: 

Software Applications

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Network Communications

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Intelligent Electronic Devices (IED)

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Gateways/Servers

OSAS (Compnents…) Software Applications: A powerful suite of flexible, user friendly software applications and graphical user-interface modules are available. These advanced user interfaces and easy to configure tools enable improved date reporting and database configuration management. Network Communications: A range of network components are available to tie new and legacy equipment into one unified system. Provide secure and reliable communications media based on experience and expertise in numerous network systems. IEDs:: IEDs 

Any device that incorporates one or more processors

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Receive or send data/control from or to an external source

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OSAS IEDs can be programmed to perform automatic control, alarm and power quality analysis

OSAS Components Gateways/Servers: Robust system for monitoring and controlling devices as well as for performance automation, IED gateways and host communication functions Monitors & Sensors: Remote monitoring monitoring and critical critical fault detection is achieved. Feeder Automation: 

Distribution automation remote terminals equipped with autosectionalising and automation restoration

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Software can dramatically reduce a customer’s outage frequency.

OSAS Overview System with conventional equipments 

Use conventional wiring to the process

OSAS Overview System with non conventional c onventional instrument transformers and modern switchgear Serial point-to-point connections (IEC 61850-9) from primary equipments to the relays

IEC 61850 Substation Architecture

Substation Automation using OSAS Radio Communications Control Center

Ethernet Substation A

HUB

Se rvi ce Entra nce Status input

Se rvi ce Entra nce

Brea ke r

Status input

Brea ke r

Radio Modem Tap Control

OSAS Advanced IED Gateway Modbus Master

Transformer

Tap Control Status input

PT CT RS-485

RS-485

Transformer

RS-485

PT CT RS-485

Breaker OSAS Basic IED OSAS Master Station

RS-485

OSAS Basic IED Breaker

Sta tus i nput RS-485

Modem

Brea ke r

Sta tus i nput

Feeder A

Rela y

Status input

Feede r B

Brea ke r

RS-485 Rela y

Rela y

Feede r C

Telephone System Substation B

Brea ke r

Status input RS-485

RS-485

Relay

OSAS Basic IED

OSAS Basic IED

Feede r D

Radio Communications Substation C

Service Entrance Entrance Modem

Servi ce Entrance Entrance

Radio Modem

OSAS Advanced IED Gateway

OSAS Advanced IED Gateway

RS-485

RS-485

OSAS Basic IED

OSAS Basic IED

Feeder A

Feeder B

Feeder C

Feeder D

Feeder A

Feeder B

Feeder C

Feeder D

Application1:Substation Automation using OSAS

Control Center: Center: master station runs operations software on a PC-based windows xp/2000 server OSAS software communicates to 

Substation A via an Ethernet link

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Substation B via a telephone modem

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Substation C has a wireless radio link to the control center

Substation Automation using OSAS Advanced OSAS IED: 

Highly accurate revenue billing

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Communication mastering functionality

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Control and equipment monitoring functionality

OSAS Basic IED: 

Monitor each feeder

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Provide real time power and energy, power quality, I/O and alarm information

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Feeder information is sent back to the master station through Ethernet gateway located in OSAS advanced IED

Application 2: OSAS System to supplement RTUBased SCADA System Control Center

OSAS Master Station

Ethernet

Power Quality Monitoring

Master SCADA

Ethe rne t

Substation A

Ethe rne t HUB

RS-485 Breaker Remote Terminal Unit

Ethernet

Modbus or DNP

Transformer PT

OSAS Advanced IED

CT

Modbus or DNP

PT CT

Breaker

PT

Modbus or DNP OSAS Basic IED

OSAS Basic IED

CT

Breaker

OSAS System to su supplem pplement ent RTURTU- Based SCADA SCADA System 

Traditional SCADA system communicate with RTU

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OSAS operations software station station ( in master station) communicate directly with the OSAS IEDs

OSAS IEDs Within the substation: 

Provide information to multiple destinations

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Provide real-time data to RTU then back to SCADA master station

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Replace several legacy transducers

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Provide real-time data to the OSAS master station through on-board Ethernet port

OSAS Implementa Implementation tion Implemented in three levels 

Level 1: Networks within switchgear

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Level 2: Networks within individual S/S

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Level 3: Network located in the control center

Level 1: IEDs networked within switchgear or a group of switchgears E.g. low voltage switchgear networked to a common PLC/gateway by the switchgear manufacturer

OSAS Implementa Implementation tion Level 2: OSAS scope starts at level 2 IEDs connected via fiber optic cables to Ethernet switches The Ethernet switches connected by fiber optic cables in parallel redundant topology or bus-ring topology Each substation shall have: Operator Automation Station (OAS), data acquisition server and database, substation annunciator, engineering automation station (EAS), event and alarm printer, GPS clock and SNTP server

OSAS Implementa Implementation tion Level 3: Interconnect the individual SA systems Provide centralized monitoring and control from the control room Central control room shall have: Operator automation station (OAS), dual redundant data acquisition server, historical data server, engineering automation station (EAS),event and alarm printer, hard copier, training simulator, GPS clock and SNTP server

OSAS Substation Architecture

OSAS CCR Architecture

OSAS Block Diagram

OSAS Block Diagram

OSAS Block Diagram

Merits 

Lower substation cost

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Reduced downtime

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Lower equipment maintenance cost

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Reduce SCADA system cost

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Low initial investment that can meet future needs