Synchrophasors and the Smarter Grid
Synchrophasor 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.
Absolute Time Synchronization Has Fundamentally Changed the World Satellite GPS RCVR GPS RCVR IRIG-B IRIG-B PMU 1 Mag/Ang Mag/Ang PMU 2 A B
Time Waveform and Phasor Representation A 2 φ ωt φ Reference
A Timing Mark on a Generator Shaft
Synchrophasors Provide a Snapshot of the Power System P= V 1 V 2 sinф / X Ф= sin -1 (PX / V 1 V 2 ) V 1 0 P V 2 Ф Increase Stable Power Transfer
Synchrophasor System Components System Components Clocks PMUs PDCs Visualization Secure communications
ISO Super PDC System Architecture Utility Control Center System PDC Neighbor Utility Control Center PDC Visualization SEL-5078 Security Gateway Station PDC Other Substations PMU PMU GPS Clock
Timing Accuracy Requirements Synchrophasors require ±500 ns Modern Clocks provides ±100 ns GPS synchronized clocks typically used
Synchrophasor System Components System Components Clocks PMUs PDCs Visualization Secure communications
Phasor Measurement Units (PMUs)
Synchronized Phasor Measurement and Distance Protection
Enabling PMU Capability in the Relay Just Say Yes! SCADA Disturbance Record High-Speed Control
C37.118 Signal Processing Filter Selecting the Frequency Response
Synchrophasor System Components System Components Clocks PMUs PDCs Visualization Secure communications
Data Concentration & Archiving Time Alignment and Superpacket Creation Protocol Conversion Data Parsing Data Rate Change Archive Maximum Data Locally
PDC Architecture
Synchrophasor System Components System Components Clocks PMUs PDCs Visualization Secure communications
Visualizing Synchrophasors Bus Voltage Instantaneous Phase Angles Line MVA PMU ID Trended Phase Angles Frequency
Synchrophasor System Components System Components Clocks PMUs PDCs Visualization Secure communications
ISO Super PDC System Architecture Utility Control Center System PDC Neighbor Utility Control Center PDC Visualization SEL-5078 Security Gateway Station PDC Other Substations PMU PMU GPS Clock
Information Security End-to to-end Security Substation Security
Securing 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 Special Protection Schemes System operators need data before things start to happen
Sometimes the Need for Speed Is Not Obvious 64 Minutes
It Can Fall Apart in Three Minutes 64 Minutes
Synchrophasors Are a Flexible Tool State measurement Disturbance recording Modal analysis Dynamic response measurement and High-Speed Protection and Control
Synchrophasor Applications
Synchrophasors Provide a Snapshot of the Power System P= V 1 V 2 sinф / X Ф= sin -1 (PX / V 1 V 2 ) V 1 0 P V 2 Ф Increase Stable Power Transfer
Streaming Data Better than SCADA - Imagine Driving in 5 Second Blinks
Synchrophas or Data is Critical
Courtesy of Entergy Corp.
Courtesy of Entergy Corp.
Synchrophasors Detect Island Courtesy of Entergy Corp.
Florida Power & Light: Distributed Generation Anti-Islanding Angle Freq df/dt Voltage
SEGIS Anti-Islanding Demo Advanced Energy led ODOT solar project: 100 kw installation Stage 3 demo planned for August 11
SEGIS Field Testing Results Island event Longest trip 1.1 seconds Utility functions Curtailment Ramp rate Power factor
Archiving System Disturbance Recording Event Capture and Analysis SEL-3306
Utilities Are Operating Closer to the Edge Margin Margin 1.0 Operating Point Bifurcation Point 0.5 0.0 PU Nominal Load 1.0 1.3 1.5 1.7
Eskom s s Voltage Stability Assessment System
The Texas Synchrophasor Network Blue outlines: Central ERCOT McDonald Observatory Wind country Waco Austin 120V and Harris 69kV Boerne (SEL) Austin Houston (SEL) Brazos Electric PMU Austin Energy PMU Funding provided by EPRI Concentrated distant load UT Pan Am 2
Estimate Thevenin Equivalent Impedances Across the Grid with Synchrophasors Vangle = δ Bus 7 WIND Pexport 500 km Thevenin Impedance jxth Central ERCOT Vangle = 0 Local conventional Pload,conv Pgen,conv Use the Excel Solver with angle measurements to minimize least-squared error and obtain Xth P VV sin( 1 2 δ X TH ) 8
A 2 Hz Mode in Ambient Oscillation Forms with High Wind Generation Small Wind (2%) without 2 Hz Cluster Big Wind (20%) with 2 Hz Cluster March 12, 02:00 03:00 Wind Generation 2% March 18, 02:00 03:00 Wind Generation > 20% 1 hour 2 Hz Cluster 9
Only Synchrophasors Provide Angle Difference Angle Difference Frequency Charts provided by University of Texas
Integration 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 46 46
Oscillations Due to Wind Farm Wind farm PMU shows many undesirable components, the worst at 14Hz 47
Big Creek Controls Rector Static VAR Compensator
C37.118 to SCADA based FACTS Control SCADA Master DNP3 Information Processor IEEE C37.118
SRP SynchroWAVe Synchroscope 230 kv Bus 115 kv Bus SEL-421 SEL-421 13.8 kv Bus
SRP Operator Closes Tie Based on Synchrophasors, 2004
Relay-to to-relay Synchrophasors for Generator Shedding
Generator Shedding Based on Angle Chicoasen Angostura
Wide-Area Protection at Relay Speeds
Modal Analysis Shows System Response 1996 Event
Slow Oscillations Facilitate Control P= V 1 V 2 sinф / X 0.4 Hz 2.5 sec. Raise Voltage Reduce Voltage
A New Tool for Old Problems Synchrophasors 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
Disturbance recording Apply Synchrophasors Now Relay-to-relay control Modal analysis Special protection schemes System control
Don t t Imagine It Engineer It What Can You Do With Synchrophasors?
URLs for More Application Information SEL 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 https://www.selinc.com/workarea/downloadasset.aspx?id=3194 Anti-islanding at FPL https://www.selinc.com/workarea/downloadasset.aspx?id=6375 UT Texas with Dr. Mack Grady https://www.selinc.com/workarea/downloadasset.aspx?id=7264 SCE Static VAR Control https://www.selinc.com/workarea/downloadasset.aspx?id=3487 Using Modal Analysis to Mitigate Power System Oscillations https://www.selinc.com/workarea/downloadasset.aspx?id=5322 Another useful website - North American SynchroPhasor Initiative (NASPI) website: http://www.naspi.org/ OGE presentation, Entergy presentation and many others