November 16, 2012 Synchrophasor Meeting Dynamic Model Validation Project Jonathan Rose Engineer, Resource Integration Sidharth Rajagopalan Engineer, Dynamic Studies

2 Need for Model Validation… Synchrophasor MeetingNovember 16, 2012 Source: sentations/1/ %20Power%20Plant%20Model%20Validation%20Using%20Disturbance%20Data.pdf

3 Validation Methodology Compare computer simulations to actual generator behavior, measured during a disturbance. Synchrophasor MeetingNovember 16, 2012 Compare Results Field Measurements PMUs, DFRs... Pass / Fail

4 Overview Near Term Goals –Validate a few generator dynamic models based on available measured response during system events. Long Term Goals –Develop plan to systematically validate generator models in ERCOT. –New responsibilities? (NERC MOD Standard) Resource Entities, ERCOT, TSP –Install measurement devices PMU at every power plant Synchrophasor MeetingNovember 16, 2012

5 Challenge #1: Gathering Measurements Existing PMUs available to ERCOT –Installed for specific purpose of transmission observability. –none measure generator output Some gen companies have continuous fault recorders –Difficult to access data. “Leap-frog” communication. –Need coordination on setting up recorders. This issue is unresolved. –Only attempted to validate Governor models. Synchrophasor MeetingNovember 16, 2012 POI Generator High-speed measurements of V, , P, Q, Hz. >= 30 samples / second. Measure unit output, not plant.

6 Possible Solution #1: Gathering Measurements Install PMU or proper set Continuous DFR at each generator –Does not need to stream live data. (Communication $$). –PMU preferred over DFRs. –Installation and Maintenance Provide easy access to data Synchrophasor MeetingNovember 16, 2012 POI Generator Need method to easily get data to ERCOT.

7 Challenge #2: Identifying Disturbances AvailableDifficult Frequency disturbancesVoltage disturbance (e.g. faults) Angle disturbance due to unit tripAngle disturbance due to line open Synchrophasor MeetingNovember 16, 2012 Problem: Some stochastic disturbances difficult to monitor and identify. Possible Solution: Move a nearby switched shunt. Change generator voltage set point.

8 Brainstorming A Synchrophasor Plan… PMUs for Operational Needs –Stream live data. –Penetration: capture system condition PMUs for Generator Model Validation –Archive data for 30 days. Data downloaded as needed. –Measure terminal behavior of each plant. Overlap? –Some generator PMUs stream data for Operations. Synchrophasor MeetingNovember 16, 2012

Questions? Thank You November 16, 2012Synchrophasor Meeting

10 Synchrophasor MeetingNovember 16, 2012 ADDITIONAL MATERIAL

11 Overview of Validation Process 1.Capture electrical measurements during a disturbance using PMU. Need plant-level or unit-level measurements. 2.Introduce disturbance and measurements into simulation. 3.Check that the simulated response matches plant actual response. 4.If not, discuss the results with the resource entity. Synchrophasor MeetingNovember 16, 2012 Field Measurem ents POI Present independent variables (V, , Hz) to Generator Test Generator Comparison Measure vs. Simulation  Pass /Fail.

12 Example – Simple Model Validation Exercise SPWG MeetingNovember 16, 2012Synchrophasor Meeting

13 Types of Measurement Devices Phasor Measurement Units –Stand-alone measurement device. High-fidelity. Synchrophasors –Relay with PMU-like features. High-fidelity. –E.g. Schweitzer 421. Digital Fault Recorders (Continuous) –Predecessor to synchrophasors. –Similar to PMUs except no GPS-clock and cannot measure angle. –May or may not be able to stream live measurements. Digital Fault Recorders (Triggered) –Oscilloscope-type measurements that are triggered. Used for relay performance reviews, event forensics, etc. SCADA Synchrophasor MeetingNovember 16, 2012

14 Measurement Device Comparison High Speed Real Time GPS Clock Angle Meas Penetra- tion Model Validation PMU & Synchroph. ~50 DFR 100’sDifficult SCADA 1000’s Governor Only November 16, 2012Synchrophasor Meeting

15 ResponseDisturbances GENFastFault, sudden angle shift due to nearby unit trip / line open. AVRFastFault, switched shunt adjust, V-schedule adjust. GOVSlowLarge unit trip anywhere. PSSFastNearby unit trip or line open. Gathering Measurements – Need a Good Disturbance! AVR GOV PSS V meas Hz d  /dt Q gen P gen The nature of the disturbance determines which system is affected. –Multiple disturbances needed to validate all parts of model. d  /dt V P gen, Q gen Machine Synchrophasor MeetingNovember 16, 2012

16 Disturbances Voltage Disturbances are difficult to find! –Wait for a fault? How know when it happened? WECC creates their own disturbances –1400 MW Chief Joseph braking resistor. Could ERCOT do similar? –Disturb generator by adjusting nearby tap, switched shunt or change Voltage set point. Chief Joseph: November 16, 2012Synchrophasor Meeting

17 Synchrophasor MeetingNovember 16, 2012