Copyright © SEL 2008

Synchrophasor-Based Monitoring, Analysis, and Control

Roy Moxley Schweitzer Engineering Laboratories, Inc.

The Power System Is Changing

Photo Courtesy of Shawn Jacobs, OG&E

‘02 ’03 8/03 ‘05 ‘06 ’06 ’07 ’07+

Synch

roph

asor

s in a

Mete

r

Synch

roph

asor

s on t

he W

eb

IEEE P

rotoc

ol in

a Rela

y

Synch

roph

asor

s in a

Rela

y

Retrofi

t Syn

chro

phas

ors

In a R

elay

Utility

Grade

PDC

SCADA Syn

chro

phas

ors

Real-T

ime C

ontro

l in

a Rela

y (Mex

ico)

SEL Synchrophasor Vision

0

5

10

15

20

25

AG10AB10BCG10ABC10

AG50AB50BCG50ABC50

AG80AB80BCG80ABC80

AG90AB90BCG90ABC90

Fault Type and Distance

Tim

e (m

s)

Local side trip times WITHOUT synchrophasors Local side trip times WITH synchrophasors

Real-T

ime V

ecto

r

Proce

ssor

Synchrophasors Are StandardSEL-421

IEEE C37.118

SEL-451SEL-487ESEL-787SEL-734 SEL Fast Message

SEL-311A, B, CSEL-311LSEL-351SEL-351SSEL-351A

Protection AND Synchrophasors

0

5

10

15

20

25

AG90AB90BCG90ABC90

AG50AB50BCG50ABC50

AG20AB20BCG20ABC20

AG10AB10BCG10ABC10

Fault Type and Distance

Tim

e (m

s)

Remote side trip times WITHOUT synchrophasors Remote side trip times WITH synchrophasors

0

5

10

15

20

25

AG10AB10BCG10ABC10

AG50AB50BCG50ABC50

AG80AB80BCG80ABC80

AG90AB90BCG90ABC90

Fault Type and Distance

Tim

e (m

s)

Local side trip times WITHOUT synchrophasors Local side trip times WITH synchrophasors

Synchrophasors do not hurt relay performance

Relaying Has No Impact on PMCU Function

No lostdata

4 4.1 4.2 4.3 4.4 4.5 4.6 4.7 4.8 4.90

1

2

3

Local bus side phase A voltage synchrophasorSynchrophasor data check

Time (s)

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

SEL Synchrophasor Equipped Devices Worldwide !

North AmericaNorth America>20,000 units>20,000 units

South AmericaSouth America>2,000 units>2,000 units

Europe/AsiaEurope/Asia>3,000 units>3,000 units

Africa/Middle EastAfrica/Middle East>1,000 units>1,000 units

Asia Asia PacificPacific

>5,000 units>5,000 units

Application Options – Not “One Size Fits All”

SEL-5078 Visualization

SEL-5077, SEL-5078 Archiving

System Operator, Reliability Council

SEL-3306 Hardware PDC SEL-5077 Software PDC

SEL-3378 Vector Processor

PMU’s

Protection and Control Time Frame

~1.0 Second ~30 Seconds

Relay Action Human ActionControl Action

METER PM 13:22

Monitor a Gen Drop Test (New Zealand)

49.1

49.3

49.5

49.7

49.9

50.1

50.3

Timestamp 5/3/2007 3:10:18.6805/3/2007 3:11:06.6805/3/2007 3:11:54.6805/3/2007 3:12:42.6805/3/2007 3:13:30.6805/3/2007 3:14:18.6805/3/2007 3:15:06.680

Whakamaru_Frequency Huntly_Frequency

Test Shows System Remains Stable When 400 MW Dropped

Frequency recordings at both ends perfectly overlap and align in time.

Malin – Round Mt. 500 kV Trips June 18, 2007

“The MRI of Power Systems”

NERC press release on Florida outage

Feb. 26, 2008:

Synchrophasors are “Like the MRI of bulk power

systems”

Synchrophasor-Based Control – Now a Reality

Big Creek Controls Rector Static VAR Compensator

SCE Uses C37.118 From Relays and PMU

SCADAMaster

DNP3

IEEE C37.118

InformationProcessor

(Harris 5000/6000, IEC 60870-103, Modbus, SEL Fast Message, SES 92, Telegyr 8979, Conitel 2020, GETAC, Recon 1.1, CoDeSys, OPC, …)

Impact of the Rector SVC: 6-14-07 (pre-SVC) vs. 8-30-07 (post-SVC)

Magunden Substation Voltage Comparison(Rector Substation Events 6-14-07 and 8-30-07)

220

222

224

226

228

230

232

234

236

238

240

-5.00 0.00 5.00 10.00 15.00 20.00 25.00

Time (seconds)

Mag

unde

n Vo

ltage

(kV)

Rector 8-30-2007 event (POST-SVC) Rector 6-14-2007 event (PRE-SVC)

The Rector SVC had the apparent effect of reducing the magnitude & duration of the fault-induced slow voltage

recovery…

6-14-2007 (pre-SVC)

8-30-2007 (post-SVC)

NOTE: Voltages shown were measured ~70 miles south of Rector Substation (actual low voltage event was of greater

magnitude at Rector substation itself)

Effect of SVC Operation on Big Creek Before -

Effect of SVC Operation on Big Creek After -

Synchronous Vector ProcessingSystem

MeasurementFunction

CalculationOutput

Designation

Send Control to System(Application)

f(x)

Apply the

Collect synchronous phasor measurements

Collect logical inputs

Perform vector and scalar math

Make decisions

Produce outputs

Report data

Select Quantities From Each PMU

PMU1PMU2PMU3

Analogs| V1 |∠V1

| I1 |∠I1

FreqPSV42TE (time error)

Binary dataStatusTriggers

Integrate Wide-Area Protection and Control

Static Var Control

SEL-421

SEL-421

SEL-421

Apply Flexible Function Calculations

IEC 61131 engineMathTrigDifferentials

Preprogrammed blocksPowerAngle differenceModal analysisStation topology check

Combine Pre-Configured with Custom Functions

Provides Function Blocks

Map PMU Quantities to Phase Angle Difference Monitor

Improve Local Measurements

V A

Substation State and Topology Processor

Refined Is, Vs, Alarms,

and Topology52

52

52

52 52 52

Identify and Quarantine Bad Data

Measurements Measurements+

Calculate Median

Measurements+

Calculate Median+

Flag and Quarantine

Set Flag

Line Trip…Stable

System Separation

Line Trip and Generation

Loss…Unstable

Real-Time Modal Analysis Monitor Predicts System Disturbances

Use Oscillation Frequency and Damping Ratio

For the complex Eigen value pair:

Oscillation frequency is:

Damping ratio is:

djω±σ=λ

πω

=2

f dosc

d

i

ωσσς+

=2

–2

Modal Analysis Shows System Response

Develop Custom ApplicationsVoltage Collapse Detection

Instability of Distributed Generation

Complex Power Swings

Others ?

Operating Point

Bifurcation Point

Utilities Are Operating Closer to the Edge

PU Nominal Load

Operating Point

Bifurcation Point

MarginMargin

1.61.51.31.00.0

0.5

1.0

Long Island: Monitor Angles Between Transmission Distribution Buses to Detect and Prevent Voltage Collapse

( )X)θcos(2V)θsin(1S 2

2s

max−=

S = P + jQ

ZL = R + jX

δ∠rV

0VS ∠

Calculate Voltage Stability Index (VSI)

SVP calculates maxima: P, Q, and S

Calculate margins:

QQQ maxmargin −=

⎟⎠

⎞⎜⎝

⎛=

max

margin

max

margin

max

margin

SS

,QQ

,PP

minVSI

PPP maxginmar −=

SSS maxmargin −=

Improve Power Swing Detection

Actual Swing from 2003 Blackout

Wide-Area Measurement Is Better than Traditional “Blinder” Methods

Impedance Loci

Wide-Area Measurement

Replace and improve on local out of step

What if load or source impedance changes?

Delta/Delta-Dot Phase Plane Analysis

-20 0 20 40 60 80 100 120 140 160 180-200

-100

0

100

200

300

400

500

Angle Difference δ (deg)

Slip

(de

g/se

c)

Delta-Dot Delta-Doubledot Phase Plane

0 0.5 1 1.5 2 2.5 3 3.5 4-40

-30

-20

-10

0

10

20

30

40

Slip (Hz)

Acc

eler

atio

n (H

z/se

c)

Use Fast Operate Control Blocks for Closed-Loop Control

Synchrophasors Are StandardSEL-421

IEEE C37.118

SEL-451SEL-487ESEL-787SEL-734 SEL Fast Message

SEL-311A, B, CSEL-311LSEL-351SEL-351SSEL-351A

Synchrophasors Provide New and Improved Capabilities

Angle measurement

Disturbance analysis

Modal analysis

Out-of-step detection

Real-time control

What Else Can They Do For You?

Thank You!Thank You!