Academic Experience with Wide Area Sensors

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Virgilio CentenoVirgilio Centeno

Virginia TechVirginia Tech

PSC, Distributed Generation, Advanced Metering and PSC, Distributed Generation, Advanced Metering and CommunicationsCommunications

March 9, 2005March 9, 2005

Clemson UniversityClemson University

Historic Development of PMU at Virginia Tech1982 - 1986 Conceptual Development1986 - 1988 Implementation1988 – 1990 Tests on Experimental Units1989 - 1991 Transfer Technology to Industry1992 – now Diverse Applications

Model ValidationOut-of Step RelayingUnit Placement State EstimationVisualizationOscillation DetectionUnit Testing Error Assessment

1999 – now Wide Area frequency Measurement

1982 – 1986 Initial Concepts

Expansion of algorithm derived for distance protectionFor computer based relays.

xi

xr

E 1 1 2E 2

21 -

2E

E12EE1

2EE1

Time as a Reference

GPS Receiver: - 1Second Pulse (±100 nS)

- Time Tag

Time Synchronization with GPS

GPS Clock:- Sampling Pulse- Accuracy reduced to 1 s ( 0.022° )

1986 GPS not fully developed and under military control

Virginia Tech Experimental PMU

First Commercial PMU

(1989-1991) Technology Transfer to Industry

1992: First Wide Area Measurement with PMUs

Duke Power

TVA

Alabama Power

Hatch

Thalmann

Duval

Vogtle

MartinGenerationSubstation

1992Measurements used for Model Validation

Georgia

Florida

Out of stepcondition

S-PMU

Relay

S-PMU

Relay

Main Problem:Communication Errors

9600 Baud Modem 4 wireleased telephone line

1993-1994 Applications: Out-Of-Step Relaying

Linear state estimator

Enhanced State Estimation State Measurement

1990 – Present: State Estimation Applications

Algorithms for PMU Placement for Obserbability

1993- Present Dynamic Applications

Unit Placement Detection of System Oscillations

Defines the interface between the GPS receiver and PMU

Defines the data format of phasors being transmitted

first transmitted SOC SMPCNT STAT Phasor #1

Phasor #2 Phasor #n FREQ DFREQ

DIG #1 DIG #K CRC last transmitted

. . .

. . . 16

4

2

2

2 2

2

2 2

4

4 4

MSB LSB DATAFORMAT

IEEE standard 1344-1995SYNCHROPHASOR

1993 – present Standardization Efforts

(March 2003) PMU Testing

Single Phase Voltage at off-nominal FrequenciesAngle vs Frequency

30

50

70

90

110

130

150

170

190

55 56 57 58 59 60 61 62 63 64 65

Frequency (Hz)

An

gle

Deg

rees

Unit A

Unit B

Unit C

Unit D

1992 – Present Wide Area Data Visualization

1995 – Present: New Devices and Concepts

89.0 90.0 91.0 92.0 93.0 94.0 95.0 96.0 97.0Seconds

-0.2

-0.1

0.0

Her

tz

Comanche Peak Nuclear Station Full Load Rejection Test

Jewett Min. -0.2186 HzOdessa Min. -0.2456 HzVenus Min. -0.2262 HzRobinson Min. -0.2344 Hz

(dev

iati

on f

rom

60H

z)

Continuum Model for Power Systems

Frequency Monitoring Network (FNET)

GPSReceiver

A/D Converter

Processor NIC

Low Pass Filter

Analog Signal

Analog Signal

Output Pulse

Synch Time Network Card

FNET - Frequency Recording Unit (FRU) DesignFNET - Frequency Recording Unit (FRU) Design

Measurements from any Single Phase 120Volt outlet

1999- Present: Frequency Wide Area Measurement

GPS/Internet Based Frequency Monitoring Network GPS/Internet Based Frequency Monitoring Network (FNET)(FNET)

Gateway Server

WANWAN TCP/IP LAN

Data Warehouse

MMI

Router

Firewall

Router

Firewall

WANWAN

FRU 1

FRU n

Internet User

FRU 2

FRU n

Internet User