synchrophasors olutions for the** smartg rid · • voltage • mw, mvar • rms magnitude •...

SYNCHROPHASOR SOLUTIONS FOR THE SMART GRID

October 5, 2011

Ken Martin Electric Power Group

Real Time Dynamics

Monitoring System Alarming

Phasor Grid Dynamics Analyzer

enhanced PDC

Presenta:on

•  Introduction to synchrophasors •  Synchrophasor characteristics •  Synchrophasor applications •  Synchrophasor systems

Tradi:onal power system measurements

•  Voltage •  MW, MVAR •  RMS magnitude •  Average

reading over 100 ms +

•  Report 1-2 sec •  Timetag at EMS

Voltage

Data output

RMS magnitude

MW MVAR

-5 0 5 10 15 20 25 30 35-1

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

0.8

1

Phasor measurements

•  Voltage •  Current •  Frequency •  Magnitude & phase

angle •  1-5 cycle averaging •  Report 10-60/sec •  Timetag at

measurement •  Can compute MW,

MVAR

Data output

-5 0 5 10 15 20 25 30 35-1

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

0.8

1

. f A

PMU

Phasor Representa:on

.

A phasor is the complex form of the AC waveform

√2 A cos (2 p ω0 t + f) A ejf

-1

-0.5

0

0.5

1

-50 0 50 100 150 200 250 300 350 400

f f A

A

Basic phasor calcula:on •  Discrete Fourier Transform

(DFT) •  Fourier coefficients from cos &

sin waves (kø) •  Multiply & sum with waveform

samples (xk) •  Time & frequency reference

arbitrary

-5 0 5 10 15 20 25 30 35-1

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

0.8

1

-5 0 5 10 15 20 25 30 35-1

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

0.8

1

φkxN

X kr cos2∑=

ir jXX −=X

φkxN

X ki sin2∑=

-5 0 5 10 15 20 25 30 35 40 45-1

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

0.8

1

Synchrophasor calcula:on •  Reference sine/cosine reference to nominal frequency (ω0) •  Time reference fixed - UTC time •  Estimation windows move in time, sinusoid reference fixed •  Measurements can be made in 1 cycle

-5 0 5 10 15 20 25 30 35 40 45-1

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

0.8

1

WINDOW 1 WINDOW 2 WINDOW 3

Reference: Cosine – black Sine - red

Waveform being sampled

Time & reference angle

.

Phase angle is computed relative to UTC time reference •  Time is common reference for all angles •  ANY phasor can be used for reference •  A time error results in an angle error

•  Time errors are detected & flagged

-1

-0.5

0

0.5

1

-50 0 50 100 150 200 250 300 350 400

f A

√2 A Actual time T = 0 Actual phasor

value

Reported phasor value

Off nominal frequency

•  f > f0, CCW rotation; f < f0, CW rotation

f2

f1

-10 0 10 20 30 40 50 60-1

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

0.8

1

-10 0 10 20 30 40 50 60-1

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

0.8

1

-10 0 10 20 30 40 50 60-1

-0.8

-0.6

-0.4

-0.2

0

0.2

0.4

0.6

0.8

1

f2 f1

f2

f1

f > f0

f < f0

f = f0 f1 f2

-‐-‐ a typical Phasor Measurement Unit

DFT

DFT

DFT Time synchronized sampling of three phase waveform. 12 samples/cycle (720/sec). Discrete Fourier Transform uses 12 samples for each phasor conversion.

60 Hz component

Symmetrical Component Transformation

Frequency & Rate-of- Change of Frequency Algorithm

Disturbance and transient detectors, data table storage

Phasors

Trigger flags

Frequency, dFreq/dt

Real Time Data Output

GPS Timing

Phasor Measurement Process

Phasors provide accurate frequency

•  Frequency is rate of change of Phase •  F = D(q-f) / (t2 - t1) •  Accuracy better than .005 Hz •  Measurement in < 1.5 cycles

Vt1

q f

Vt2

Phasors provide MW, MVAR

•  Power P = V I cos(q-f) = VI = Vx Ix + Vy Iy •  Reactive Power Q = V I sin(q-f) = V (jI)

= Vy Ix - Vx Iy

V e = Vx + j Vy

I e = Ix + j Iy

jq

jf q

f

Phasors indicate safe power flow

•  Power flow follows voltage phase angle –  Power flow: P = V1 V2 sin(θ - ø)/Z

•  Synchrophasors measure phase angle with universal time –  Allows comparison over wide area

•  Across lines for traditional 2 machine stability

•  Across regions to monitor bulk power flow

V1 e V2 e jq jf

Line impedance Z

P

Substation 1 Substation 2

0 45 90 135 1800

1

0 90 180

P Unsafe

Safe

Applica:ons – data analysis

•  Off-line analysis •  Use recorded data

–  Verification of operations –  Analyze dynamic

performance –  System model maintenance

© Electric Power Group 14

Model Valida:on: Ringdown analysis of real data

The modal estimates (dotted line) are a good fit to the real data , indicating that

the ringdown analysis results are accurate

Dominant mode at .29 Hz---close to the simulated mode

© Electric Power Group

Inter-‐area System Swing •  Frequency:

F = d/dt •  Clearly shows system

acceleration •  Shows reaction

progressing through system: –  Yellow nearest event –  Purple furthest away –  Green near middle

•  High-speed, precise timetag allows these measurements

System monitoring & visualiza:on

•  Wide-area displays –  Actual measurement in real-time

(strip-chart) –  System setup & operation

•  Operation use –  Operational awareness –  Confirmation of dynamic operation

(SCADA too slow) –  Overall system –  Detail reporting


Wide Area Situa:onal Awareness -‐ EI

November 9, 2010

Wide Area Situa:onal Awareness – WECC

System monitor & alarms

•  Integration of all data sources –  Phasors for dynamic operation –  EMS for static reporting

•  Operational systems & alarms –  Limit alarms

•  Line loading •  Phase angle, cut plane

–  State estimation

•  Particularly from phasors –  Low damping –  Islanded sections –  Event location

Ve-jf Ve-jf

Ve-jf Ve-jf

Spectral Monitoring of Select Signal

Mode Estimates

Most Significant Mode

Small Signal Monitoring


Other monitor metrics …detect Grid Stress (angle separa:on).

…detect Dangerous Oscilla:ons – reveal low damping.

…detect Frequency Instability / Islanding.

…detect Generator or Line Trip condi:ons.

…detect Low Voltage (Instability) condi:ons.

…determine System Norm or Baseline.

…perform Event Analysis .

Grid stress -- Angle separation

Small Signal instability -- % damping

Frequency Instability -- cohesive-ness

Dangerous inter-area Oscillations – dynamic stress

System control applica:ons

•  System protection & control –  Wide area problem detection –  Low and high speed operation

•  Applications include –  Out-of-step detection & remediation –  Excessive power flow relief –  Reconfiguration for high phase

angles –  System oscillation damping –  Controller modulation & supervision –  Relay adaptive control & supervision

PMU PDC (Data Concentrator)

~ SVC

)( Controller

PMU

PMU

Signal Delay -‐ PMU to PDC

•  Direct connection through local hub •  Ave delay 4.4 ms, max 5.4 ms

•  Remote installation, 200 mi distance •  2 routers, synchronous WAN, 128 KBPS •  Ave delay 17.5 ms, max 18.7 ms

•  Communication with Ethernet connections •  10M BPS system

0 500 1000 1500 2000 2500 3000 3500 40004.2

4.4

4.6

4.8

5

5.2

5.4

5.6

5.8Delay - ABB PMU

Milli

seco

nds

Data Points0 200 400 600 800 1000 1200 1400 1600

16.8

17

17.2

17.4

17.6

17.8

18

18.2

18.4

18.6

18.8Delay - McNary 500 PMU, samples

Milll

isec

onds

Data Points

Comparison of Frequency & Phase Angle -‐ Power Flow

Grand Coulee frequency - blue, Coulee - Vincent phase angle - red, San Onofre power - green

~0.4 sec

Power Compensation (southern Cal)

Initial fault

GC frequency N. Washington

•  Event occurred in N. Washington where frequency recorded

•  Reaction recorded in Los Angeles area

•  Power system event reaction travels slower than phasor measurement and communication

•  An event can be measured, the severity estimated, and appropriate control action in another area can be taken before adverse action occurs

WECC Wide Area Control

•  Tie lines from the Pacific NW to California (red)

•  Loss of generation in California –  Tie lines overload –  N-S systems go out of

step –  Systems separate –  Large load loss

•  Control strategy –  Phasors detect swing,

data sent to controller in NW (green) - (0.2 s)

–  Drop generation to prevent tie line overload (0.5 s)

–  Action complete before overload occurs (1.0 s)

P H O E N I X A R E A

M I G U E L N . G I L A

V A I L P A L O V E R D E

C H O L L A G L E N

C A N Y O N N A V A J O S P R I N G - E R V I L L E

F O U R C O R N E R S

G R E E N L E E W E S T M E S A

S A N J U A N B L A C K W A T E R C O R O N A D O

A R T E S I A A M R A D

C A L I E N T E D I A B L O

D E N V E R A R E A C R A I G

R I F L E B O N A N Z A B E N L O M O N D

C A M P W I L L I A M S

M I D P O I N T V A L M Y

T R A C Y H A R R Y A L L E N

M A R K E T P L A C E I N T E R - M O U N T A I N

S I G U R D H U N T E R / E M E R Y

P I N T O R E D B U T T E D E V E R S L O S

A N G E L E S A R E A

M E D F O R D M A L I N

R O U N D M T . O L I N D A

T A B L E M T . V A C A - D I X O N

T E S L A S A N L U I S

G A T E S D I A B L O C A N Y O N M I D W A Y

S U M M E R L A K E G R I Z Z L Y B R O A D M A N P O R T L A N D

A R E A H A R T F O R D M I D W A Y

C H I E F J O E S P H

G R A N D C O U L E E N A N E U M

L O W E R M O N U M E N T A L

D W O R S H A K T A F T G A R R I S O N T O W N S E N D

B R O A D V I E W C O L S T R I P

J I M B R I D G E R L A R M I E

R I V E R S T A . B O R A H B R A D Y

S E A T T L E / T A C O M A A R E A

S A N F R A N C I S C O A R E A


Large genera:on loss example •  2750 MW Generation loss

in SW near Phoenix •  Intertie operating 2/3

capacity •  Frequency drop near

generators immediate and large (plot b)

•  Power ramp (plot a) and phase angle ramp (plot c) immediate & steady

•  Voltage dip actually delayed start but drops fast

•  Frequency may be better indicator

•  Model controller detected swing correctly

•  (Actual swing was barely stable)

Overall event – voltages over 20 sec

Event detail – 2 sec, voltages in plot d


PMU’s w GPS

(Phasor Data Concentrator)

Real Time Monitoring & Alarming Platform

(Offline Analysis Software System)

3rd Party Historian

Basic Synchrophasor Network Architecture

Current Grid-‐wide/ISO system •  Hierarchal architecture •  Transmission Owner (TO)

–  Installs PMUs & communication –  Has PDC & applications for own PMUs –  Stores data locally

•  ISO/RTO –  Coordinates installation & data flow –  Collects data for grid-wide

measurement

•  Issues include –  Data identification –  Data sharing & ownership –  Maintenance & problem notification –  Transmission delays

Application

TO PDC

PMU

TO PDC

TO PDC

PMU

PMU

PMU

PMU

PMU

PMU

PMU

PMU

Application

ISO PDC

Application

Application

Application

Application

N. America WISP ERCOT MISO NEISO NYISO PJM TVA Southern Co

World Wide China Japan India Russia Slovenia Denmark Germany France Spain S. Africa Brazil Mexico

Synchrophasor projects


30

Standards IEEE C37.118.1 & C37.118.2

•  IEEE C37.118.1 covers the measurement –  Phasor and frequency –  Steady-state and dynamic conditions –  Includes measurement tests and limits

•  IEEE C37.118.2 covers communications –  Describes a simple messaging –  Includes message contents and formats –  Communication methods & protocols open –  RS232 serial and IP TCP & UDP usually used

•  Final approval expected in December 2011 •  Publication expected in January 2012


31

Standard IEC 61850-‐90-‐5

•  Work started in October 2009 •  Includes several additions to 61850

–  New modeling –  USV for routable sampled values –  End-to-end security features

•  Completed document to IEC in October 2011 •  Final approval expected late 2011


Future needs

§  Full grid visualiza-on

§  Wide area controls

§  Alarms for less predictable situa-ons –  System & equipment oscilla-ons –  Excessive system phase angles

§  Integra-on of renewables –  Less predictable –  Reduced iner-a

§  Many others!!!

08.17.10

201 South Lake Avenue, Ste 400 Pasadena, CA 91101 626-‐685-‐2015 www.ElectricPowerGroup.com

Real Time Dynamics

Monitoring System Alarming

Phasor Grid Dynamics Analyzer

enhanced PDC for Control Centers/

Substations

Ken Martin

[email protected]

Thank You -‐ Ques:ons?

synchrophasors olutions for the** smartg rid · • voltage • mw, mvar • rms magnitude •...

Documents