Copyright © SEL 2008

Multi-vendor Experiences with

IEC 61850 Installation, Testing,

Configuration, Diagnostics, and

Upgrades

David Dolezilek

Schweitzer Engineering Laboratories, Inc.

Practical Uses of IEC 61850 Protocols

and Synchrophasors

GOOSE in a Centralized Remedial Action

Scheme (CRAS)

GOOSE versus hard-wire protective trip

RTU I/O collection via GOOSE

Diagnostics tools for GOOSE “virtual wiring”

Recent Global IEC 61850 installations

Improving RAS with synchrophasors

Remedial Action Schemes

Southern California Edison (SCE)

Tested Digital Communications Speed

Strive to mitigate thermal overload and

instability throughout

transmission territory

13.313

3 4

26.7

8.4

Peer-to-Peer Control

Tim

e (

ms)

RAS Round-Trip

SEL Mirrored Bits® Communications

SEL IEC 61850 GOOSE

Non-SEL IEC 61850 GOOSE

Detect Decide Trip

Performance Criteria: Detect, Calculate,

React 50 ms To / From any Location

Test starts when Monitor

detects Contact Input 1

Monitor chooses action to take

Monitor sends monitor alarm

Central Processor receives

monitor alarm

RAS enabled in Central Processor?

Central Processor chooses

action to take

Central Processor sends

decision alarm

Mitigator receives decision alarm

Mitigator chooses action to take

Mitigator closes trip output contact

Monitor detects mitigation trip output

as Monitor Contact Input 2

Scope measures difference

between Contact Input 1 and 2Yes

Initial Testing Verified Time Budget

Using Three IEDs 740 Km Apart

Next: Arming via SEL an Dell Computers

Multiple Devices Demonstrated for

WECC RAS Committee

Within One

Hour, Five

New

Devices

Were

“Digitally”

Wired

Typical: GOOSE Trip Tansit 1.50 msec

Central Processing Time 2.083 msec

Monitor is 60 miles distant. Mitigators are local to CP.

Mitigation GOOSE transit, subscription, output - 3 msec or 11 msec

Jim Bridger Power Plant

Simultaneous, Independent Operation

DNP Gateway

IEC Logic

Controller

I/O

Modules

IEC Logic

Controller

IEC Logic

Controller

I/O

Modules

I/O

Modules

DNP Gateway

IEC Logic

Controller

I/O

Modules

IEC Logic

Controller

IEC Logic

Controller

I/O

Modules

I/O

Modules

RAS DRAS C

Three Levels

of Voting

Crosspoints Voting

InputInput Input

Input Voting

Output Voting

Output

Jim Bridger Substation

RAS Uses Crosspoint Switch

Crosspoint Switch

f

tCB

Opens

Tripping

Outputs

Trigger

Inputs

X

Trip G2

N5

N4

XN3

XN2

N1

Trip G1

Output RemediationContingency

Trip G3

X

Trip G4

X

Bypass

C1

X

Bypass

C2

X

X

X XX

X

Preloaded and Ready to Go

Designed to Handle Multiple, Closely

Timed Events

N-EventsIN1

N=1

S1

IN6

N=20

S1

IN6

N=6

S2

First Event

Example 1 Example 2

Time (s)

System State

t=5st=0s

PacifiCorp / Idaho Power Remedial Action

Scheme Eliminates Congestion

Stability improvements increase capacity 50%, avoid blackouts

Fastest control

system in the

world

Training / Testing / Playback Simulator

Test Simulator Plugged Into RAS C

Protection-Class Features

Deterministic, high-speed, peer-to-peer

protocol used between RAS controllers

No backplanes to fail

No auxiliary power supplies

MS Windows® NOT used in RAS controller

All controllers embedded

Identical logic in all six controllers

Florida’s International

Drive 1999 Project: Distribution Automation

at Transmission Speeds

Switching With a Recloser…

Manual Switching = 1 hour

Switching w/Recloser = 10 seconds

Recloser + Control Without Communications

…vs. Distribution at Transmission SpeedSEL & S&C for International Drive

SEL-351S + Communications

Smart Switching = 0.1 second

Multivendor IEC 61850

CFE Parque Eolico La Venta

Existing Generators at Wind Farm

Biggest Wind Farm Project in Mexico

CFE expects to generate close to 3 GW

by 2014 in “La Ventosa”

Substation Expansion - New Generators

SEL - MX060018 Project Satisfies

Newest SICLE Design With IEC-61850

SICLE is Spanish Acronym for

“Integrated System For Substation Local

Control”

CFE Specifies SICLE for integration of high

voltage substations, SISCOPROMM for low

voltage

CFE Decided to Build Small but

Meaningful Substation

CFE wanted to prove 61850 was real

Include as many vendors as possible

Add other redundant IEDs in parallel

Demonstrate true functionality on the

network

Prove multi-vendor interoperability

“This is, without any doubt, a great

advancement for the integration of control

and protection systems, and for integration

of the IEC 61850 International standard.”

David Lancha, Project Manager, IBERINCO

Proven. Reliable.

Complete.

World’s First Multisupplier

IEC 61850 System in Service

Since 2006

Wind Farm Under Construction

50BF

50BF

51PHS

87T

51PHS

51NHS

51NLS

87B

RD

50BF

79

21PP

87L

La Venta II Substation

Protection Requirements

Design #1 Used IEC 61850 Part 5, SEL Methods

in IEDs, IEC 61850 in SCADA Gateway

SEL-451-4

SEL-451

SEL-451-4

SEL-451

SEL-387E

SEL-451-4

SEL-451

SEL-311L

SEL-421

SEL-487B

SEL-3351

SEL-3351

SEL-3332

SEL-3332

230KV Line

LVD93100

230KV

Autotransformer

LVD92010

230KV Tie

LVD97010

230KV Bus

Diff

LVDDB9

Redundant

HMI

Redundant

SCADA

Gateway

Information Processor Serves DNP/Conitel as

SCADA Gateway and OPC to HMIs

CFE Requested IEC 61850 in all IEDs

SEL-421 – Distance

SEL-311L – Current Differential

SEL-451 – Distribution

SEL-387E – Transformers

SEL-487B – Buses

SEL-451-4 – Bay Control

SEL-3351 Rugged Computer

SEL ACSELERATOR Architect –

Substation Configuration Language

(SCL) Engineering SoftwareSEL-710 – Motors

SEL-2411 – Automation

Controller SEL-751A – Feeders

Meet CFE Substation Protection

Requirements Using IEC 61850

Conventional wiring and IEC 61850 GOOSE

Test performance of conventional wiring vs.

GOOSE for protection functions

Determine if all relays will interoperate and

perform as desired

IEDs approved by CFE

Design #2 Used IEC 61850 Part 8,9 in the IEDs IEC 61850 From SEL for Every Application in Bays

SEL-451-4

SEL-451

SEL-451-4

SEL-451

SEL-387E

SEL-451-4

SEL-451

SEL-311L

SEL-421

SEL-487B

SEL-3351

SEL-3351

SEL-3332

SEL-3332

230KV Line

LVD93100

230KV

Autotransformer

LVD92010

230KV Tie

LVD97010

230KV Bus

Diff

LVDDB9

Redundant

HMI

Redundant

SCADA

Gateway

Next CFE Chose to Demonstrate Multi-

vendor Interoperability

System integrates devices from multiple

vendors

SEL Siemens

GE ZIV

RuggedCom Team ARTECHE

Other vendors invited but did not have

IEC 61850 available or not approved by CFE

Two Different Engineering Groups

Working in Parallel to Integrate IEDs

HMI LN reporting and bay level

GOOSE IEC 61850 integration

being done by Iberdrola

SCADA Gateway LN reporting and

station level GOOSE IEC 61850

integration being done by SEL

New Products for CFE : Bay Control, SCADA

Gateway, and IEC 61850

SEL Scope: Panel Design for Parque Eolico

“Wind Farm” and Intertie Substation

Design #3 Used IEC 61850 Part 8,9 in the IEDs Added IEC 61850 Devices From Other Vendors

SEL-451-4

SEL-451 SEL-451

SEL-387E

SEL-451

SEL-311L

SEL-421

SEL-487B

SEL-3332

230KV Line

LVD93100

230KV

Autotransformer

LVD92010

230KV Tie

LVD97010

230KV Bus

Diff

LVDDB9

Redundant

HMI

Redundant

SCADA

Gateway

GE F650 BC

Siemens 7SJ62

GE F60

Siemens 7SJ61

ZIV BC

GE T60

GE F35 GE L90

ZIV HMI

ZIV HMI

ZIV CPT

Panels Ready for Installation

System Architecture

Router

+ Firewall

Remote HMI

RuggedCom

Fiber-Optic

Ring

DNP

Conitel

SW-4

SW-5

SW-3

SW-1

SW-2

GE F650 BC

SEL-451 50BF, 25, 27

SEL-387E

GE T60 87T

GE F60 50, 51HS

GE F35 50, 51TZ

Siemens 7SJ62 50, 51LS

Siemens 7SJ61 50, 51N

SEL-451-4 BC

SEL-451 50BF, 25, 27

ZIV 6MCV BC

SEL-421 21, 67

SEL-279H 79

SEL-451 50BF, 25, 27

GE L90 87L

SEL-311L

SEL-487B 87BGPS

ZIV CPT ZIV HMI ZIV HMI

SEL-3332

SCADA Gateway

SEL Construction, Factory Acceptance

Test (FAT), Training, Commissioning

IEC 61850 SCL Replaces Wired

Connections With Logical Connections

GOOSE Messages for Protection

CFE wanted to see performance comparison between wired and GOOSE

CFE chose to test breaker failure protection scheme using GOOSE

Primary protection trip

Breaker failure relay retrip

Breaker failure relay trip

Breaker failure trip reception by bus differential relay

Trip to all breakers in bus

Customer Factory Acceptance Test

GOOSE Retrip Operation 12.5ms Faster

Than Parallel Hardwire at La Venta

GOOSE Breaker 21 TRIP A

Wired Contact Breaker 21 TRIP A

12.5 ms Difference

Between Inputs

86FI Operation: GOOSE 8 ms Faster

CFE Project Results

Retrip test; GOOSE three-fourths cycle faster

Breaker failure scheme; GOOSE half-cycle

faster – wiring scheme still has to go through

physical lockout (86) relay, which adds 6 to 8 ms

Configuration and troubleshooting made simpler

with sequential events recorder (SER) and

event reports

Traffic did not affect performance of SEL

devices

Project Engineering Revealed

Necessary Communication Parameters

Time synch method - chose SNTP

Sacraficed accuracy to use Ethernet

Changed back to IRIG later

Number of client associations – chose 6

Two redundant HMIs

Remote and local engineering workstations

Two redundant SCADA gateways

Interlock and Automation Projects

Dictated GOOSE Requirements

Number of outgoing GOOSE messages -

eight

Number of incoming GOOSE messages - 16

Number of incoming GOOSE bits

Bay control – 128

Relay –16, 128 depending on application

Parque Eolico La Venta II

PP&L Modernized

From PLCs to IEDs

Eliminate programmable devices

Digital transducers

PLCs

Eliminate other components

24 Vdc supplies

Interface relays

External fault detectors

Streamline, Reduce

Complexity With

IEC 61850 Design

Reduce Hardware Components With

IEC 61850 Design

Design Computers

Substation

PLCs & Comm.

Processor

Bay

PLCsRelays

Metering

IEDs

Ethernet

SwitchesSER Total

PLC 3 5 22 24 16 4 1 75

NGS 3 1 0 24 0 2 0 30

Display Redundant Data Sources via HMI

L2 P disagrees with other IEDs Faulty L2 P manually removed

Using IEC 61850 Methods for RTU

Replacement and Distributed Automation

RTU Vendor Went AWOL

No New Units, No Product Support

Over 400 pad-mounted switchgear in service

50 to 100 new each year

Three switch configurations controlling

one to six circuit taps or “ways”

Desire to simplify configuration, add

engineering access, and improve logic

Numerous I/O Configurations Must Fit

in Fixed Small Space

DNP3 serial over radio to SCADA Master

changing to DNP3 / TCP in future

RTU Real-Time Values via Internal and

External Communications Connections

RTU Replacement Network Could Also

Connect I/O of Relays and Meters

Example system database

32 AC analog inputs

2 DC analog inputs

24 digital inputs

16 digital outputs

192.168.0.15 192.168.0.25 192.168.0.30

192.168.0.20

SCADA

Master

DNP3 Serial

Ethernet

SwitchGOOSE Messages

PAC_MASTER

PAC_Slave_A PAC_Slave_B PAC_Slave_C

Data Flow Acts the Same as Distributed

RTU I/O Panels But Performs Better

SCADA Master

Field Inputs

GOOSE Inputs

DNP3 Response

DNP3 Command

Contact Output

GOOSE Outputs

Multi-vendor Configuration Requires

Stand-Alone Tool Specifically for 61850

Alternate traditional UCA2 method of

proprietary settings makes multi-

vendor systems difficult

Configure IED via International Standard

Substation Configuration Language, SCL

Start with IED capability

description, ICD file

Create configured IED

description, CID file

Edit only what you

choose

No accidental changes

Minimize verification

testing

Load File in IED, or Send to Colleague Via

email to Add Future IED Subscriptions

“Best Practice” Provides Contextual

Names – Generic Names Less Useful

Best practice provides specific names whenever possible

Exceptions include generic logic points, unnamed contact I/O

Generic Specific

Use Unique Name and Revision ControlAsk IED Directly to Verify Present Configuration

Solicit identification report from IED

IED name reveals file name and revision

ConfigVersion reveals default SCL file that

configuration was developed with

IED GOOSE Reports Are Essential

Review receive and

transmit configuration

Quickly review network

settings

Analyze GOOSE statistics

and diagnostics

Immediately pinpoint

source of problem

Identification (ID) Reports Provide

Source / Destination of “Virtual Wiring”Mismatched Configuration Explains Failure

ID shows incorrect revision of PAC configuration

Once corrected, GOOSE report shows correct

revision as part of GOOSE reference name

Analyze Contents With Knowledge

of Configuration File

Failed GOOSE, Other Alarms Displayed

and Sent via Email, Voice, Text Message

Cigre

Multi-

vendor

System

of 12

Vendor

IEDs

Support 8 Unique GOOSE Publications,

16 Subscriptions, 24 for Complex

Interlocking

SEL-451-4

Sisco software

IED on PC

GE D60Siemens

6MD669

Areva

P444

Siemens

7SA525

Siemens

BC1703

GE

F650

Toshiba

GRZ100

ZIV

IRV-ATeam

Arteche

SEL-421

Second Generation Modernization

Began in 2006

Complete modernization

of 30 substations ranging

in voltage level from

13.8 kV to 138 kV

Elektro Network

Includes IEC 61850,

Telnet, FTP, and

SEL Protocols

Substations:

Guarujá 2 – first modernized substation energized June 12

2007 – seven complete

2008 – eight complete Sao Paulo State,

Brazil

Guarujá 2

Guarujá 3

Fiber Optics Replace Copper

KONYA Industrial Park

Chooses SEL and IEC 61850

500 large to mid-size electricity-dependent

tenants: plastics, machinery, pharmaceuticals

Park management responsible for infrastructure:

electricity, gas, water, traffic, security

One 100 MW transformer and three 33 kV

tie lines from National Grid

65 MW maximum demand increasing by 15%

every year

SEL-2407

GPS-Receiver

Clock

Front-End 1

Substation

Computing

Station 1

Front-End 2

Substation

Computing

Station 2 Station 3 Station 4 Station 5 Station 6 Station 7 Station 8

3 Tie Lines (6 Future)

6 x SEL-311L

Server 1 Operator

Station 1

42-Inch LCD

Monitors

SEL-3401

GPS-Clock

54 SEL-751A Relays and 38 SEL-311L Relays

Server 2Operator

Station 2

Switch

8 Switching Stations, 99 Feeders

Switch

Printers

Control Center

Manages 165

Distribution

Substations

24 km redundant fiber-optic ring

Future distribution automation additions

Use Modern Communications for

Diagnostics – FTP, Telnet, email

GEESE Migrate to Africa

Stations Include IEC 61850 MMS and GOOSE

City Power Pennyville – 19 bays , 2 bus

sections, 3 transformers

City Power Khanyisa – similar to above with

36 bays

City of Cape Town – 2 complete substations

Nelson Mandela Bay Municipality

Three new substations in 2008

Each based on IEC 61850

City Power Johannesburg

Harley Street Substation

Control Center

IEC 60870-5-101

Fdr 29Fdr 1

SEL

SEL-1102

SEL-2410SEL-2410

Switch Switch

SEL-1102 Gateway, 2 SEL-2410s, 36 Bays With SEL-451 Relays

Electricity of Vietnam (EVN)

State-owned utility established 1995

Generation, transmission, and distribution

for whole country

4 transmission

companies

79,800 km of

distribution lines

Growing Electricity Demand

Forecasted growth 17% per annum until 2025

0

100

200

300

400

500

600

1995 2000 2005 2010 2015 2020 2025

Production

Sales

Tera

watt-H

ours

First Phase – Substation Modernization

Began in 1999

First computerized 220 kV substation

commissioned in Ho Chi Minh City

This success resulted in digitizing more

substations through 2003

Early Substation Modernization

Conventional protection and control using

DNP3 serial and hardwired connections

Problems with incompatibilities between

multiple manufacturers’ IEDs

Second Phase – Standardization

To improve IED compatibility, EVN issued

specification for substation automation based

on UCA2

Based on this, first large-scale substation

automation system (SAS) was implemented

220 kV Thu Duc Substation

Upgraded

Protection

System

Architecture

220 kV

66 kV Busbar

Phase 1 Phase 3

Phase 2

220 kV

110 kV

Phase 1 Phase 3 Phase 2

Third Phase – IEC 61850

IEC 61850 Part 10 approved Oct. 2005

EVN standardized for future projects –

new and retrofit

All 500 kV

backbone

substations

upgraded by

2010

New System Requirements

Dual redundant fiber-optic LAN with no

single point of failure

IEC 61850 for all substation communication

IEC 60870-5-101 for SCADA

Host 1 Host 2Engineering

(Bridge to SCADA)HIS Server Router to WAN

Backup

IED

Backup

IED

Main

IED

Main

IED

Bay

Devices

Bay

Devices

Main

NIM

Backup

NIM

Bay CubicleBay Cubicle

Bay Cubicle

Option 2

Option 1

LAN 1

LAN 2

GPS Clock

Backup

IED

Main

IED

Bay

Devices

Fiber-Optic

Ethernet

100 Mbps

Standard System Hardware Architecture

Computerized Control and Monitoring

Local HMI,

engineering console,

and historian

Redundant system

servers running on

Windows® 2000 or Linux®

Old Protection Panels Replaced

Microprocessor-based relays perform

protection, control, and monitoring

Outdoor Cubicles Reduce Cabling

Existing Copper Cabling Binh Long Substation

Copper

Cabling

Reduced

@STATION System Overview

HMI1 HMI2ENG

HISGW

LAN / WAN

Primary Equipment

Meter

Hardware

Connections

Relays / BCUs

IEC 61850

Legacy Device GatewayRugged Computing Platform

SCADA Gateway

Test Results

User Interface FeatureRequired by

EVNTested

Display Response Time < 1 s < 1 s

Data Entry Response Time < 1 s < 1 s

Display Update Rate < 2 s < 2 s

Update Completion Rate < 1 s < 1 s

Test Results

User Interface FeatureRequired by

EVNTested

Alarm/Event

Response Time< 1 s < 1 s

Alarm Acknowledge/

Delete Time< 2 s < 2 s

Report and Logbook

Response Time< 0.5 min < 0.5 min

Display Color Printout

Response Time< 0.5 min < 0.5 min

User Interface FeatureRequired by

EVNTested

Console Inhibit Time for

Display Hardcopy< 2 s < 1 s

Analog Data

Collection Rate– < 2 s

Status Indication

Collection Rate– < 1 s

Failover Time Between

Main 1 and Main 2– 0 s

GOOSE Exchange Time < 10 ms < 8 ms

Test Results

Benefits of IEC 61850 SAS

Faster system integration with IED

interoperability

Reduction of copper cabling and

hardwiring GOOSE for peer-to-peer data exchange

Outdoor cubicles adjacent to feeder or bay

System malfunctions reduced by nearly

50%

What is a Synchrophasor?

v(t)

0

A

wt2

A

Reference

Time Waveform

and Phasor Representation

Absolute Time Synchronization Has

Fundamentally Changed the World

GPS RCVR

PMU 1

A B

Satellite

GPS RCVR

PMU 2

IRIG-B IRIG-B

Mag/Ang Mag/Ang

Direct State Measurement

SYNCHROPHASORS

GPS provides common time reference

Measure state vector

Measure currents, too

Synchronously!

Every second

Every cycle

Synchrophasors Provide a “Snapshot”

of the Power System

P= |V1| |V2|sinФ / X Ф= sin-1(PX / |V1| |V2|)

V1∠0 V2 ∠ФP→

Increase Stable

Power Transfer

Relays Are Right for Synchrophasors

Phasor measurement and control unit

(PMCU) ≥ PMU

Minimal incremental cost

Reduced current and voltage connections

High-accuracy measurements

High reliability and availability

Future control applications

Relays are everywhere

What Operators Did Not See Aug. 14th

64 Minutes

Utilities Are Operating Closer to the Edge

MarginMargin

1.0 1.3 1.5 1.7PU Nominal Load

1.0

0.5

0.0

Operating

Point

Bifurcation

Point

Long Island: Monitor Angles Between

Transmission Distribution Buses to

Detect & Prevent Voltage Collapse

X)θcos(2

V)θsin(1S

2

2

smax

ZL = R + jXVS 0

Vr

S = P + jQ

Apply Remote Synchronizing

115 kV

Bus

230 kV

Bus

13.8 kV

Bus

SEL-421

SEL-421

Improved View:

Synchroscope

and Freq Plot

make it easier

for operators

“The MRI of Power Systems”

NERC press release on Florida outage Feb. 26,

2008:

Synchrophasors are “Like the MRI of bulk power

systems”

SCE Uses C37.118 From

Relays and PMU

SCADA

Master

DNP3

IEEE C37.118

Information

Processor

Harris 5000/6000,

IEC 60870-103,

Modbus, SEL Fast

Message, Telegyr

8979, Conitel 2020,

CoDeSys, OPC, …

Distributed Generation Creates

Islanding Problems

Transmission

Network

DG

SEL-3378

Synchrophasors Detect and Correct

Islanding Problems

Defensive Strategies Working Group

New York State Reliability Council

NYSRC asked SEL to propose solutions

Mitigate impact of major disturbances on the

New York electric system

Blackout mitigation and prevention

Separate into “islands” using transmission

system fault protection relays

Canada

SEL Synchrophasor Total

Potential Worldwide!

North America

142,085 units

South America

15,903 units

Europe / Asia

4,115 units

Africa / Middle East

5,085 units

Asia

Pacific

45,793 units

Real-World Example – Line Repair

Error Detection

Relay-to-Relay

Synchrophasors for

Generator Shedding

Synchrophasors Make

CFE’s Grid Smarter

115 kV Network

400 kV

900 MW

AngosturaTapachula

City

400 kV

Southern Region Load

SabinoChicoasen

National

System

400 kV

Load Shedding Based on Angle

SynchrophasorsTrip

Generator

Detect and Control Adaptive Islanding

Transmission

Network

SEL-451

Relay / PMU

SEL-3378 SVP

Unintentional

Islanding

Distribution

Network

SEL-451

Relay / PMU

Over Angle Protection Holds System

Together

Area 1

Heavy

Load

Area2

Link 1

Link 2

Area 3

Light

LoadTrip

Generation

SEL-421 SEL-421Synchrophasors

(Chicoasen – Angostura) > 5° Trip Generation

Today: Most Processing Is at the Master

Finds topology

Purges bad data

Estimates stateMaster

RTU RTU

Asynchronous

Scan

~5 seconds per scan

. . . can have partial

information from

two or more

physical systems –

due to faults, switching,

swinging, tap changes.

One Utility’s View of Several Data

Streams

Bus Voltage

Line

MVA

Frequency

Instantaneous

Phase Angles

Trended

Phase Angles

PMU ID

Local Calculation of Line Temperature

Improves Power Transfer Reliability

+ +

Line Temperature = f (Ambient Temp, Current, Line Orientation, Season)

IEEE Synchrophasors Compatible

With IEC 61850 Networks Possible Future GOOSE or 9-2 Extension

IEEE C37.118,

Telnet, tunneled

serial

Verify CT wiring,

phase rotation,

settings

Determining the State of a Power System

4

3

2

1

34

232

231

12

V

V

V

V

I

I

I

I

Y

I12 I34

I231

I232

V1 V4V3V2

State Vector

Traditional RAS Clearing Time Budget

Relay I/O Module Computer I/O Module Relay Breaker

1 Cycle0 Cycle-1 Cycle

Relay

Detects

Fault

Relay Trips/

Asserts Contact

Output

RAS Controller

Issues Gen

Breaker Trip

2 Cycles

Relay Receives

Trip Command

and Trips Gen

Breaker

Breaker Trip

Time

3 Cycles 6 Cycles

Total RAS Clearing Time

SVP RAS Clearing Time ¾ Cycle Faster

Improving RAS with Synchrophasors

Direct state measurement is now practical

because of the widespread availability of

Synchrophasors

The SVP performs local direct state

measurement and control

Wide area RAS schemes are improved

because synchrophasors reduce the amount

of information communicated to the master

station

What Does a Future “Worst-Case

Scenario” Look Like?

Detect potential unstable operating conditions

Control islanding

Detect system oscillation before criticality

Minimize problems automatically

Synchrophasors Empower the Future