Using Synchrophasors for Preventing Cascading Outages

CAMS/RRPA Panel SessionMitigation and Prevention of Cascading Outages:

Methodologies and Practical ApplicationsPES General Meeting, Vancouver, Canada

July 24, 2013Eric Heredia (BPA) and Ryan Quint (BPA) on

behalf of Dmitry Kosterev (BPA)

BPA “Defense in Depth” approach Reliability starts with good planning – long-range and

operational planning… But, actual system conditions are often different from what is planned …

State estimator based real time contingency analysis … But, your model may be wrong (model errors, control failures, etc) …

… or a dispatcher may not have adequate time to respond to an event …

Intrinsic indicators of system stability

IEEE Boise, Nov 16, 2012

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BPA PMU Project

• 5-year, $35M investment began in 2010• PMU Installation

– 50 substations and wind sites– 120 PMUs installed

• Control center upgrades for system operators– PDCs, Applications, Archives

• Wide Area Controls (RAS)

IEEE Boise, Nov 16, 2012

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ApplicationsThe value of the investment will be realized

through the deployment of applications

• Engineering Applications– Understand system performance issues, make

better capital investments, set safer operating limits

• Real-Time Wide-Area Situational Awareness– Give grid operators better visibility of the system

state

• Wide Area Controls– Increase stability limits

IEEE Boise, Nov 16, 2012

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Model Validation for Better Planning• BPA has installed PMUs at power plant POIs• General Electric Company implemented disturbance playback function

in GE PSLF• BPA developed Power Plant Model Validation (PPMV) application using

PMU data

~

Record: -POI bus voltage-POI bus frequency-Power plant MWs and MVARs

Point of Interconnection

V I

Model Validation for Better Planning• What a good models looks like:

Blue line = actual recordingRed line = model

Voltage and frequency are inputsActive and reactive power are “measures of success”

Model Validation for Better Planning• What a bad model looks like:

Blue line = actual recordingRed line = model

Voltage and frequency are inputsActive and reactive power are “measures of success”

Mode Meter• Mode Meter (Active)

– Developed by Dan Trudnowski at Montana Tech

– Application estimates frequency and damping of inter-area oscillations from ambient data

– Available to BPA dispatchers– Operating procedures are under

development

IEEE Boise, Nov 16, 2012

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Display of oscillation trend

MMM: N-S_A DampingMMM: N-S_A2 DampingMODE METER NS-A LOW DAMPING LIMIT

percent

percent

15:00 15:30 16:00

2.00

4.00

6.00

8.00

10.00

12.00

0.00

15.00

5

9.90

9.27

MMM: N-S_A Frequency MMM: N-S_A2 Frequency

Hz

Hz

7/9/2013 2:14:48 PM 7/9/2013 4:14:48 PM2.00 hours

0.205

0.210

0.215

0.220

0.225

0.230

0.235

0.240

0.245

0.200

0.250

0.217

0.217

Oscillation Detection Application• Oscillation Detection Application (Active)

– Developed by Dan Trudnowski at Monata Tech– Scans voltages, frequencies, active and reactive power for signs of

sustained or growing power oscillations– Applied to interties, load centers and generating facilities

IEEE Boise, Nov 16, 2012

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The oscillation spectrum is divided into four frequency bins

A bin turns to red when a sustained oscillation is detected

How can we use angles?

Wide-Area Stability Controls• Wide-Area Stability Controls (Under Development)

– Takes synchronized wide-area measurements to determine voltage stability risks– Enable fast switching of reactive devices

IEEE Boise, Nov 16, 2012

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Malin 500-kV Bus Voltage

0

0.2

0.4

0.6

0.8

1

1.2

1.4

4 5 6 7 8 9 10 11 12

Time (sec)

Vo

ltag

e (p

er u

nit

)

Disturbance

Timely actions are needed to ensure the system stability

Defense in Depth Study

Value of Synchrophasor Investment

IEEE Boise, Nov 16, 2012

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• Improved capital investment– Better understanding of the system risks through deployment of

engineering analysis applications

• Improved reliability and large scale outage avoidance– Better situational awareness by dispatchers of oscillation and voltage

stability risks– Wide area control schemes and defense in depth to deal with

extreme events

• Reliable wind integration– Improved modeling, validation– Dynamic transfer capability