Synchrophasors and the Smarter Grid - IEEE PES Boston · Apply Synchrophasors Now Disturbance recording Relay-to-relay control Modal analysis Special protection schemes System control

Copyright © SEL 2011

Synchrophasors and the Smarter GridSynchrophasors and the Smarter Grid


A synchrophasor is a phasor measurement with respect to an absolute time reference. With this

measurement we can determine the absolute phase relationship between phase quantities at different

locations on the power system.

““SynchrophasorSynchrophasor””


Absolute Time Synchronization Has Absolute Time Synchronization Has

Fundamentally Changed the WorldFundamentally Changed the World

GPS RCVR

PMU 1

A B

Satellite

GPS RCVR

PMU 2

IRIG-B IRIG-B

Mag/Ang Mag/Ang


ωt

φφ

Time WaveformTime Waveform

and Phasor Representationand Phasor Representation

Reference

A

2


A Timing Mark on a Generator ShaftA Timing Mark on a Generator Shaft


Synchrophasors Provide a Synchrophasors Provide a ““SnapshotSnapshot””

of the Power Systemof the Power System

P= |V1| |V2|sinФ / X Ф= sin-1(PX / |V1| |V2|)

V1∠0 V2 ∠ФP→

Increase Stable Power Transfer


Synchrophasor System ComponentsSynchrophasor System Components

System Components

● Clocks

● PMUs

● PDCs

● Visualization

● Secure communications


ISO

Neighbor Utility Control Center

Visualization SELVisualization SEL--50785078

Utility Control Center

GPS ClockGPS Clock

Security GatewaySecurity Gateway

Station PDCStation PDC

System PDCSystem PDC

PDCPDC

Super PDCSuper PDC

PMUPMUPMUPMU

Other Substations

SystemSystem

ArchitectureArchitecture


Timing Accuracy RequirementsTiming Accuracy Requirements

● Synchrophasors require ±500 ns

● Modern Clocks provides ±100 ns

● GPS synchronized clocks typically used



System Components

● Clocks

● PMUs

● PDCs

● Visualization



Phasor Measurement Units (PMUs)Phasor Measurement Units (PMUs)

Synchronized Phasor Measurement Synchronized Phasor Measurement

and Distance Protectionand Distance Protection


Enabling PMU Capability in the RelayEnabling PMU Capability in the Relay

SCADA

Disturbance RecordHigh-Speed Control

Just Say Yes!


C37.118 Signal Processing FilterC37.118 Signal Processing Filter

Selecting the Frequency ResponseSelecting the Frequency Response



System Components

● Clocks

● PMUs

● PDCs

● Visualization



Data Concentration & ArchivingData Concentration & Archiving

● Time Alignment and Superpacket Creation

● Protocol Conversion

● Data Parsing

● Data Rate Change

● Archive Maximum Data Locally


PDC ArchitecturePDC Architecture



System Components

● Clocks

● PMUs

● PDCs

● Visualization



Bus Voltage

Line MVA

Frequency

Instantaneous Phase Angles

Trended Phase Angles

PMU ID

Visualizing SynchrophasorsVisualizing Synchrophasors



System Components

● Clocks

● PMUs

● PDCs

● Visualization



ISO

Neighbor Utility Control Center

Visualization SELVisualization SEL--50785078

Utility Control Center

GPS ClockGPS Clock

Security GatewaySecurity Gateway

Station PDCStation PDC

System PDCSystem PDC

PDCPDC

Super PDCSuper PDC

PMUPMUPMUPMU

Other Substations

SystemSystem

ArchitectureArchitecture


Substation Security

Information SecurityInformation SecurityEndEnd--toto--End SecurityEnd Security


Securing the InformationSecuring the Information

● Establish an electronic security perimeter• Use multilayered system architecture that

includes a firewall• Encrypt communications in/out of

substation• Disable unused ports on all devices• Send C37.118 data using UDP Secure

(UDP_S)

Multi-layered Secure Architecture


SCADA Speed Sufficient for Many SCADA Speed Sufficient for Many

Special Protection SchemesSpecial Protection Schemes

System operators

need data before things start

to happen


Sometimes the Need for Speed Is Not ObviousSometimes the Need for Speed Is Not Obvious

64 Minutes


It Can Fall Apart in Three MinutesIt Can Fall Apart in Three Minutes

64 Minutes


Synchrophasors Are a Flexible ToolSynchrophasors Are a Flexible Tool

● State measurement● Disturbance recording

● Modal analysis● Dynamic response

measurement

and…

High-Speed Protection and Control


Synchrophasor ApplicationsSynchrophasor Applications


Synchrophasors Provide a Synchrophasors Provide a ““SnapshotSnapshot””

of the Power Systemof the Power System

P= |V1| |V2|sinФ / X Ф= sin-1(PX / |V1| |V2|)

V1∠0 V2 ∠ФP→

Increase Stable Power Transfer


Streaming Data Better than SCADAStreaming Data Better than SCADA

-- Imagine Driving in 5 Second BlinksImagine Driving in 5 Second Blinks


Synchrophasor Data is Critical

Copyright © SEL 2011Courtesy of Entergy Corp.Courtesy of Entergy Corp.

Copyright © SEL 2011Courtesy of Entergy Corp.Courtesy of Entergy Corp.


Synchrophasors Detect IslandSynchrophasors Detect Island

Courtesy of Entergy Corp.Courtesy of Entergy Corp.


Florida Power & Light: Distributed Florida Power & Light: Distributed

Generation AntiGeneration Anti--IslandingIslanding

Angle

Freqdf/dt

Voltage


SEGIS AntiSEGIS Anti--Islanding DemoIslanding Demo

● Advanced Energy led● ODOT solar project: 100 kW installation

● Stage 3 demo planned for August ‘11


SEGIS Field Testing Results SEGIS Field Testing Results

● Island event � Longest trip 1.1 seconds

● Utility functions � Curtailment � Ramp rate

� Power factor


Archiving SystemArchiving System

SEL-3306

••Disturbance RecordingDisturbance Recording

••Event Capture and Event Capture and

AnalysisAnalysis


Utilities Are Operating Closer to the EdgeUtilities Are Operating Closer to the Edge

MarginMargin

1.0 1.3 1.5 1.7PU Nominal Load

1.0

0.5

0.0

Operating

Point

BifurcationPoint


EskomEskom’’s Voltage Stability Assessment s Voltage Stability Assessment

SystemSystem


UT Pan Am

Austin

McDonald

Observatory

Austin 120V and

Harris 69kV

Waco

Houston (SEL)

Boerne (SEL)

Brazos Electric

PMU

Austin Energy

PMU

• Funding provided by

EPRI

Wind

country

Concentrated distant load

Blue outlines: Central ERCOT

2

The Texas Synchrophasor Network

Bus 7

WIND

Bus 7

WIND500 km

Local conventional

Pload,conv − Pgen,conv

Pexport

Thevenin Impedance

jXTH

Central ERCOT

Vangle = 0

Vangle = δ

Use the Excel Solver with angle measurements to minimize least-squared error

and obtain Xth

Estimate Thevenin Equivalent Impedances Across

the Grid with Synchrophasors

80 1 2 3 4 5 6 7 8 9 10 11 12

)sin(21 δ•≈TH

X

VVP


2 Hz

Cluster

March 18, 02:00 – 03:00

Wind Generation > 20%

March 12, 02:00 – 03:00

Wind Generation ≈ 2%

Big Wind (20%) with 2 Hz ClusterSmall Wind (2%) without 2 Hz Cluster

A 2 Hz Mode in Ambient Oscillation Forms with

High Wind Generation

9

1 hour


Only Synchrophasors Only Synchrophasors

Provide Angle Provide Angle

DifferenceDifference

FrequencyFrequency

AngleAngle

DifferenceDifference

Charts provided by University of Texas


46 46

Integration of Renewable EnergyIntegration of Renewable Energy

● With over 28GW of wind power in the SPP interconnection queue, this is a big deal!

● OG&E requiring a PMU at the point of interconnection for every wind farm

● Important to monitor power quality and dynamic response

47

Oscillations Due to Wind FarmOscillations Due to Wind Farm

� Wind farm PMU shows many undesirable components, the worst at 14Hz


Big Creek Controls Rector Big Creek Controls Rector

Static VAR CompensatorStatic VAR Compensator


C37.118 to SCADA based FACTS ControlC37.118 to SCADA based FACTS Control

SCADAMaster

DNP3

IEEE C37.118

Information

Processor


SRP SRP –– SynchroWAVe SynchroscopeSynchroWAVe Synchroscope

115 kV

Bus

230 kV

Bus

13.8 kV Bus

SEL-421

SEL-421


SRP Operator Closes Tie Based

on Synchrophasors, 2004


RelayRelay--toto--Relay Relay

Synchrophasors for Synchrophasors for

Generator SheddingGenerator Shedding


Generator Shedding Based on AngleGenerator Shedding Based on AngleChicoasen Chicoasen –– AngosturaAngostura


WideWide--Area Protection at Relay SpeedsArea Protection at Relay Speeds


Modal AnalysisModal Analysis

Shows System ResponseShows System Response

1996 Event


Slow Oscillations Facilitate ControlSlow Oscillations Facilitate Control

P= |V1| |V2|sinФ / X

RaiseVoltage

Reduce

Voltage

0.4 Hz → 2.5 sec.


A New Tool for Old ProblemsA New Tool for Old ProblemsSynchrophasorsSynchrophasors

● Are cost effective● Provide accurate time-synchronized

event information● Can be used to meet NERC PRC-002-2

requirements

● Are being used for new approaches in protection and control

Apply Synchrophasors NowApply Synchrophasors Now

� Disturbance recording

� Relay-to-relay control

� Modal analysis

� Special protection schemes

� System control


DonDon’’t Imagine It t Imagine It –– Engineer ItEngineer It

What Can You Do With What Can You Do With

Synchrophasors?Synchrophasors?


URLs for More Application InformationURLs for More Application InformationSEL website:

● Eskom Voltage Stabilty

https://www.selinc.com/WorkArea/DownloadAsset.aspx?id=6378

● Solar Generator Control – PV Powered https://www.selinc.com/WorkArea/DownloadAsset.aspx?id=8494

● Generator Black-start – SRP


● Anti-islanding at FPL https://www.selinc.com/WorkArea/DownloadAsset.aspx?id=6375

● UT Texas with Dr. Mack Grady


● SCE Static VAR Control https://www.selinc.com/WorkArea/DownloadAsset.aspx?id=3487

● Using Modal Analysis to Mitigate Power System Oscillations


Another useful website - North American SynchroPhasor Initiative (NASPI) website: http://www.naspi.org/

● OGE presentation , Entergy presentation and many others

Documents

Synchrophasors and the Smarter Grid - IEEE PES Boston · Apply Synchrophasors Now Disturbance recording Relay-to-relay control Modal analysis Special protection schemes System control