Clemson University Power Systems Conference Synchrophasor Technology in Control Centers Clemson University, SC March 12, 2014 Vikram S. Budhraja
Outline Synchrophasor Technology Infrastructure Lessons Learned from Major Blackouts Synchrophasor Technology in Control Centers Monitor, Diagnose and Act Wide Area Visualization Angle Difference Oscillations Voltage Sensitivities Alarming Use Cases Illustrating Use of Synchrophasor Technology in Control Room Summary 1
Synchrophasor Technology Infrastructure Time Synchronized High Resolution Measurements and Wide Area Visualization 1. Measurement (CT, PT) 2. Conversion to phasor quantities - PMU 3. Data Aggregation and Time Alignment 4. Data Transport 5. Wide Area Visualization MEASUREMENTS Phase Conductor 1 Potential Transformer Instrumentation Cables Courtesy: Adapted from EIPP presentation Substation Current Transformer Burden Optional Analog Signal Conditioning Unit PMU 2 PMU DATA CONCENTRATION & TIME ALIGNMENT Substation 2-N 3 Data Concentrator Burden Utility s Footprint TO 1 Regional View IEEE C37.118 5 Secure Internet Utility s Footprint TO 2 Regional View Wide Area View IEEE C37.118 Common ISO View ISO IEEE C37.118 ISO Data Concentrator 4 TO 2-N DATA TRANSPORT WIDE AREA VISUALIZATION 2
Lessons Learned from Major Blackouts WECC 1996 blackout Lack of wide area situational awareness EI 2003 blackout Lack of wide area situational awareness Pacific SW 2011 blackout Lack of phase angle separation monitoring Similar blackouts: Italy 2003 Europe 2006 India 2012 3
Synchrophasor Technology in Control Rooms Monitor, Diagnose and Act Operator s Mission: Keep the lights on! Wide Area Visualization, Situational Awareness Monitoring, Alarms, Analysis and Corrective Actions 4
Synchrophasor Technology in Control Rooms Monitor, Diagnose and Act Synchrophasor technology enables operators to get early warning and take timely actions through monitoring: Wide Area Situational Awareness Grid Stress phase angle differences Oscillation low damping, modal frequency Voltage Instability low voltage zones and areas approaching nose of the Power-Voltage curves Reliability Margin How far are we from the edge? sensitivity metrics 5
Monitoring Wide Area View and Grid Metrics Angular Stability Angle Sensitivities Grid Stress Phase Angle Separation Wide Area View Margin How far are we from the edge? Dangerous Oscillations Modal Damping & Energy Voltage Stability Low Voltage Zone Frequency Instability Frequency variations across grid 6
Real-Time Monitoring Display - Dashboard Wide Area View Incident Indicator Angle Differences System Frequency Trend System Frequency Value Screenshot of RTDMS Real Time Dynamics Monitoring System Synchrophasor technology provides wide-area visibility to enable operators to Monitor, Diagnose, and Act Electric Power Group. Built upon GRID-3P platform, US Patent 7,233,843, US Patent 8,060259, and US Patent 8,401,710. All rights reserved. 7
Wide Area Monitoring Phase Angle Displays Focus On Phase Angle Difference Between Sources and Sinks Angle Difference Display Trends Arrow shows Phase Angle Difference between two PMUs may not represent a transmission line Incident Indicator Screenshot of RTDMS Real Time Dynamics Monitoring System Polar Chart - Common Reference Angle 8
Wide Area Monitoring Oscillations Modal frequency Damping % Energy Level Screenshot of RTDMS Real Time Dynamics Monitoring System Detect oscillations of interest based on event analysis and system characteristics in each interconnection Monitorsmodal frequency, energy, damping, mode shape in real-time 9
Characterizing Oscillations Frequency and Damping Oscillatory Frequency & Damping Interpretation Desirable Condition Oscillation Frequency Decay Rate (i.e., Damping) Well Damped: 10% or Higher Damping Poor Poorly Damped: Less Than 3% Damping Growing Oscillations- Negative Damping Dangerous Screenshot of RTDMS Real Time Dynamics Monitoring System 10
Wide Area Monitoring Voltage Sensitivity Analysis Voltage Sensitivity Chart Screenshot of RTDMS Real Time Dynamics Monitoring System Monitor Voltage Stability at the desired PMU w.r.t changes in power flow on a Path Provide operators real-time assessment of the Power Voltage curve and a calculation of change in voltage per 100 MW in power flow 11
Wide Area Diagnostics in Real Time RTDMS Real Time Dynamics Monitoring System - Used in Control Rooms at ISOs and Utilities Frequency Trends Chart Voltage Angle Difference Chart Power Flow Chart Mode Trend Chart Frequency Numerical Chart Voltage Polar Chart Voltage Sensitivity Chart Mode Damping Gauge Screenshot of RTDMS Real Time Dynamics Monitoring System Islanding Detected 12
Use of Alarms in Real-Time Operations Early Warning of Grid Stress (Increasing Phase Angle differences) Pinpoint Zone of Incident Location (First Mover PMU - frequency, voltage etc.) Assess Incident Severity (Number of Metrics that Alarm) Assess Vulnerability to Cascade (Multiple Alarms in Large or Multiple Footprints) 13
Use of Alarms in Real-Time Operations Early Warning of Grid Stress (Increasing Phase Angle differences) Pinpoint Incident Location (First Mover PMU - frequency, voltage etc.) Assess Incident Severity (3 Metrics alarm) Assess Vulnerability to Cascade (Multiple Alarms in Large or Multiple Footprints) 14
Use of Alarms in Real-Time Operations Early Warning of Grid Stress (Increasing Phase Angle differences) Pinpoint Incident Location (First Mover PMU - frequency, voltage etc.) Assess Incident Severity (3 Metrics alarm) Assess Vulnerability to Cascade (Multiple Alarms in Large or Multiple Footprints) 15
Use of Alarms in Real-Time Operations Early Warning of Grid Stress (Increasing Phase Angle differences) Pinpoint Incident Location (First Mover PMU - frequency, voltage etc.) Assess Incident Severity (3 Metrics alarm) Assess Vulnerability to Cascade (Multiple Alarms in Large or Multiple Footprints) 16
Synchrophasor Technology in Operations Use Cases Use Cases Illustrating Use of Synchrophasor WECC Simulations of Stressed Conditions Pacific Southwest Blackout Simulations 17
Monitoring WECC System WECC Simulation Case: California - Oregon Intertie Stress Test COI Malin Grand Coulee, WA Power Flow - COI 6370 MW WECC Stress Test: 1. Increase Power 5680 along MW COI Path 2. Monitor Grid Stress via Angle Difference between Grand Coulee in Washington Devers in Southern California 4860 MW 3. Monitor Voltage Sensitivities at Malin in Oregon Devers Angle Difference - Grand Coulee and Devers 129.3 Degrees 88.1 Degrees Operator s Action: Validate 108.5 system Degrees status and re-dispatch Screenshots of RTDMS Real Time Dynamics Monitoring System 18
Monitoring WECC System WECC Simulation Case: California - Oregon Intertie Stress Test COI Malin Grand Coulee, WA Power Flow - COI 6370 MW WECC Stress Test: 1. Increase Power 5680 along MW COI Path 2. Monitor Grid Stress via Angle Difference between Grand Coulee in Washington Devers in Southern California 4860 MW 3. Monitor Voltage Sensitivities at Malin in Oregon Voltage at Malin 540 kv 520 kv Operator s Action: Validate system status and re-dispatch 493 kv Devers Screenshots of RTDMS Real Time Dynamics Monitoring System 19
Monitoring WECC System WECC Simulation Case: California - Oregon Intertie Stress Test Grand Coulee, WA Power Flow - COI 6370 MW Malin 5680 MW 4860 MW COI Voltage Sensitivity - Malin Voltage Sensitivity - Malin Voltage Sensitivity - Malin -2kV/100MW -4kV/100MW Operator s Action: Validate system status and re-dispatch -6kV/100MW Devers Screenshots of RTDMS Real Time Dynamics Monitoring System 20
Case Study Pacific Southwest Blackout Simulation of a real event Event occurred on Sep 8, 2011 and took about 12-minutes Simulation Created Based on Sequence of Events in NERC/FERC report Outage of Hassayampa-North Gila line Outage of IID transformers Load drop in IID and CFE Loss of CFE and IID generation Separation of SDGE at San Onofre Nuclear Gen. Station (SONGS) Simulation results match the event Simulation developed to validate event and train operators 21
Pacific Southwest Blackout Simulation 22
Pacific Southwest Blackout (Simulation replay: Just after start of event) ALARMS: Angle Differences Angle Differences: INCREASE Angle Differences in Southwest increase and get alarmed. Simulations enable operators to test corrective actions. 23
Pacific Southwest Blackout Alarm Panel Alarms just after start of event Alarms just before system separation The number and severity of alarms triggered increases as the event worsens. Operators can evaluate corrective actions to prevent worsening of event and cascading. 24
Pacific Southwest Blackout ALARMS Multiple Angle differences, Devers bus voltage & sensitivity, Power flow on South of SONGS Reduce power flow on South of SONGS Drop load in SDGE Increase generation in SDGE Add voltage support at Devers substation Heavy power transfers from SCE to SDGE System in insecure state 25
What can operators focus on with Uses of Synchrophasor Technology in Control Rooms Synchrophasor Technology? Wide Area View - Situational Awareness Grid Dynamics Monitoring Phase Angle Difference Damping and Oscillation Voltage and Angle Sensitivities Diagnosing Grid Conditions Alarms, Metrics Timely Corrective Actions Integrate Renewables, Improve Asset Utilization, Prevent Blackouts and Enable Faster Recovery 26
Q&A Thank You! Vikram Budhraja Budhraja@ElectricPowerGroup.com 201 S. Lake Ave., Suite 400 Pasadena, CA 91101 (626)685-2015 www.electricpowergroup.com 27