Texas A&M University

PSERC

T-17 Enhanced Reliability of Power System Operation Using Advanced

Algorithms and IEDs for On-Line Monitoring

Texas A&M University

IAB Meeting, May 18-20, 2005

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PSERCParticipants

Academic Team Members

PI: M.Kezunovic (TAMU)

Co PI: A.Abur (TAMU)

S. Meliopoulos (Georgia Tech)

R. Shoureshi (Colorado School of Mines)

Student Team Members

Yang Wu, Luo Xu, Nitin Ved, Goran Latisko, Jun Zhu (TAMU)

Industry Team Members

TVA (M. Ingram), Centerpoint (D. Sevcik), ABB (M. Subramanian), AEP (D. Krummen), Entergy (L. Priez), Mitsubishi (D. Wong), Tri-State G&T Association (A. Mander), TXU (J. Bell), WAPA (P. Kaptain)

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PSERCIntroduction

• Project duration: June 1, 2002-May 31, 2005

• This is an extension of the previous work on Fault location and State estimation

• This project was aimed at: - Definition of new concept for automated analysis - Development of algorithms - Demonstration through simulation

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PSERCBackground

RAW DATARAW DATA

PROCESSED DATAPROCESSED DATA

IEDsIEDs

Automated Analysis SystemAutomated Analysis System

Remote Control CenterRemote Control Center

VSDBVSDB TSSETSSE FAFLFAFL SSSVSSSV

DFRADFRA DPRADPRA CBMACBMA PQMAPQMA

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PSERCObjectives

• Develop substation automation system which enables: • Integration of data from multiple IEDs• Processing of data at substation level by

implementing novel applications• Sharing of results with other substations

and remote control centers• Develop methods of detecting and

identifying network parameter errors

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PSERCSubstation Developments

Software Architecture

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PSERCSubstation Developments

Software Architecture

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PSERCSubstation Developments

Substation Topology

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PSERCSubstation Developments

Integrated GUI

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PSERCSubstation Developments

Integrated GUI

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PSERCSubstation Developments

IED Data Simulation – Data Flow

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PSERCSubstation Developments

IED Data Simulation – Substation Data Model

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PSERCSubstation Developments

IED Data Simulation – Faults and Switching Sequences

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PSERCSubstation Developments

IED Data Simulation – Errors Insertion

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PSERC

• Verifies the correctness of substation IED data before they are stored into the substation database. The IEDs can be:• Analog – (currents, voltages) and/or• Digital – (statuses of contacts of circuit

breakers)

Verification of substation database (VSDB)

Substation Developments

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PSERCVSDB - algorithmSubstation Developments

T o p o l o g y l o a d

f u n c t i o n

T o p o l o g y l o a d

f u n c t i o n

I n p u t l o a d

f u n c t i o n

D o u b l e c u r r e n t m e a s u r e m e n t

c h e c k f u n c t i o n

K i r c h o f f ’ s c u r r e n t l a w

c h e c k f u n c t i o n

B r a n c h s t a t u s c h e c k f u n c t i o n

T i m e s e r i e s c h e c k f u n c t i o n

R e p o r t g e n e r a t i o n

T o p o l o g y f i l e C O M T R A D E f i l e s

D a t a f r o m A T P

G R A P H I C A L

U S E R I N T E R F A C E

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PSERC

• Monitors and verifies switching sequences of circuits breakers in the substation

• Traces and concludes what reasons caused extensive switching

Substation Switching Sequences Verification (SSSV)

Substation Developments

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PSERC

SSSV

Substation Developments

Sequence & topologyInformation file

(info.txt)

COMTRADE files(ss.CFG, ss.DAT)

SwitchingSequenceAnalysis

Report file(report.txt)

SequenceInformationDetractor

Detractedswitching

information

OUPUT

Switching Sequence Verification

INPUT INPUT

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PSERC

• Analyzes the protection (relay and circuit breaker) operations

• Verifies data consistency of relay event report and oscillography file

Digital Protective Relay Analysis (DPRA)

Substation Developments

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PSERCDPRA

Substation Developments

Fault Report (local relay)

Setting FilePerformance Specification

Fault Report (remote relays)

Fault Report(other fault analysis

applications)

COMTRADE File

(digital signals)

Event Report

Hypothesis of Protection Operation

Facts of Protection Operation

Disturbance Information

Protection Operation Prediction ES Module

Validation and Diagnosis ES Module

Analysis Report

Validation and diagnosis of relay operation

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PSERCDPRA

Substation Developments

Begin

Fault analysis applications based on advanced algorithms and techniques are

available?

Use disturbance information from

these applications

The local relay indicates Zone 1 fault?

Use disturbance information from the

local relay

Find the remote relay which indicates

Zone 1 fault

Use disturbance information from the

remote relay

Yes

No

Yes

No

Over

Detecting source of disturbance information

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PSERC

• VSDB analysis application• SSSV analysis application• DPRA analysis application• Integrated GUI• Substation Data Model in ATP enabling simulation of CT,

PT, CCVT, CB statuses and DFR data for arbitrary Faults and CB switching sequences

• Substation Topology Description in SCL • Digital Protective Relay Model in C++• Converter from PL4 -> COMTRADE file format• Custom COMTRADE file viewer

Software

Project Deliverables

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PSERC

Documentation

Project Deliverables

• Statement of work

• Functional Requirements

• Implementation Description

• Testing

• Conclusion

• Appendices – demonstration scenarios

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Parameter error detection and identification

• Causes:

Network parameters change due to environmental conditions

Network parameters are incorrectly recorded after maintenance

Modeling errors may show up as parameter errors

PSERC

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Parameter error detection and identification

• Effects:

State estimator will generate bad data flags

Good measurements will be incorrectly discarded by the bad data processor

Estimated state will be BIASED !

PSERC

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Parameter error detection and identification

• Challenge: Suspecting errors in all network

parameters will lead to an exponentially complex problem.

Bad analog measurements may exist simultaneously with incorrect network parameters.

PSERC

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Parameter error detection and identification

• Proposed approach: Apply the method of Lagrangian which

was previously successfully applied to circuit breaker status error identification.

Develop an automated procedure to account for different types of parameter errors (transmission line parameters, transformer taps, shunt cap/reactance).

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Parameter Error Identification Method

et ppp

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2

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n

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n

tn

tn

c

zr

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C

IH

CWH 0

00

0

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rS

t

p

p

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WHS

987

654

3211

EEE

EEE

EEE

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8

2

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EHIs n

tsRsr cov

tSrS covcov

Solve for the state variables:

Normalizing λ:

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Numerical Example: 14-bus system

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Numerical Example:Test A: Measurement p45 is wrong.

Test B: Reactance of line 4-5 is wrong.

81.088186.2912

172.8344108.4855

280.2699165.5449

91.35468.5355

109.408414.1172

196.9072256.0877

Test BTest A

Normalized residual / multiplierMeas. or

Constraint

mp45mp24

mp25

45x

24x

25x

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Benefits:

• State vector dimension remains fixed, so even very large scale SE problems can be handled.

• Bad analog measurements and parameter errors can be differentiated.

• No need to pre-specify the suspect parameter.

• Existing WLS state estimator code can be revised to incorporate this capability.

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PSERCConclusions

• All project goals are accomplished• Deliverables are being prepared (will be

available August 31, 2005)• Software demonstration is available (will

be presented during the poster session)• Sponsors for future field implementation of

the specific scenarios of the proposed concept are found:

- EPRI - Department of Energy - Vendor