PI/PSLF Based Model Validation Application Eric Bakie and Milorad Papic WECC JSIS Meeting Tempe, AZ January 21-23, 2014 1
OUTLINE 1. Background Information 2. What is PI/PSLF Based PPMV Application? 3. IPCO PI/PSLF Based Tools 4. Play-In validation examples using PI data 5. Lessons Learned and Future Work 2
1. Background Information 3 Grid Planning and Operating Decisions relay on good/realistic models of power system and its elements such as (generators, lines, transformers, loads, etc.) Having realistic models is very important for safe, reliable and economic system operation Validation and benchmarking of planning and operation models have always received a great deal of attention in the past and will receive increasing attention in the future by the utility industry Need for Validation exist for both Component and System-wide Models Observation, measurement and analysis of multiple system events provide the best opportunity for model validation
1. Background Information 4 After major disturbances on July 2 and August 10, 1996, the WSCC Control Work Group (CWG) and the Modeling and Validation Work Group (M&VWG) were tasked with developing guidelines for testing generators, excitation systems, power system stabilizers (PSS) and turbine governors for all units greater than 10 MW for verification of reactive limits, proper performance of the dynamic control systems, and validation of the computer models used for stability analysis. NERC Recommendation 14 from August 14, 2003 The regional reliability councils shall within one year establish and begin implementing criteria and procedures for validating data used in power flow models and dynamics simulations by benchmarking model data with actual system performance. Validated modeling data shall be exchanged on an inter-regional basis as needed for reliable system planning and operation. NERC/FERC Recommendation 17 from September 8, 20111 WECC, as the RE, should lead other entities, including TOPs and BAs, to ensure that all facilities that can adversely impact BES reliability are either designated as part of the BES or otherwise incorporated into planning and operations studies and actively monitored and alarmed in RTCA systems.
1. Background Information 5 Study of WECC frequency Events by BPA over years and by IPC just recently indicates in many cases a wide discrepancy between simulations and recording of disturbance events. Finding from BPA show that differences in frequency have been noted in both the initial transient dips and in the settling frequencies. Assessment of the first transient dip is important for load shedding while the settling frequency is a measure of the responsiveness of turbine-governors in the system. Model validation by IPCO System Planning was performed to screen the quality of the dynamics models used to represent the turbine-governor system for all Units in Idaho system for ten major events in 2013. PI Data was used as the model validation input data.
1. Component & system-wide Model validation Component Model Validation Generator model Load model HVDC, SVC model, etc. System-wide model validation is not done routinely at present. Power flow simulation results are compared with time-synchronized recordings of bus voltages, angles, and key paths flows. The following aspects of a power system model that need to be matched to a specific event include: Network topology Generation dispatch Load profile Load dynamics and composition Power plant dynamics 6
1. Background Information 7 Several NERC MOD Standards deal with power system models and their verification/validation to ensure they are accurate and up to date. MOD 012 requires power plant owners to provide power plant data for dynamic simulations MOD 026 requires power plant owners to verify that the provided dynamic models of excitation controls are accurate and up to date MOD 027 requires power plant owners to verify that the provided dynamic models of governors and turbine controls are accurate and up to date MOD 032 1 exists in conjunction with MOD 033 1, both of which are related to system level modeling and validation. Reliability Standard MOD 032 1 is a consolidation and replacement of existing MOD 010 0, MOD 011 0, MOD 012 0, MOD 013 1, MOD 014 0, and MOD 015 0.1, and it requires data submission by applicable data owners. Standard MOD 033 1 is a new standard, and it requires each Planning Coordinator to implement a documented process to perform model validation within its planning area. Validation using disturbance recordings has been recognized to be an acceptable method for periodic model validation.
1. Background Information 8 Disturbance based model validation provides: A very effective way of filling in aspects of the models that cannot be validated effectively or safely through baseline testing A very effective way of detecting when baseline testing has produced misleading or inaccurate modeling The opportunity to observe and analyze generating unit behavior in operational situations that cannot possibly (or safely) be realized in the staged conditions of baseline testing. The opportunity to detect failures, changed adjustments, drifting, and improper operation of equipment that have occurred since baseline tests were done. [Ref. Power Plant Model Validation in BPA, July 12, 2012]
2. PPMV Application [Ref. BPA PPMV, Nov. 2011] 9 General Electric implemented a disturbance play-in function in their PSLF simulator in 2001. The function plays in recorded voltage bus, voltage and frequency at a power plant Point of Interconnection. The power plant active and reactive power are compared between the actual disturbance data and play-in simulations. BPA found that were quite few instances when a power plant model failed to match a disturbance response event. The most common modeling deficiencies include Power System Stabilizers (PSS) Turbine-governor models Generator Inertia
2. PPMV Application Power Plant Model Validation (PPMV) Application 10 Build a sub system by extracting data from the latest base case. Create a *.dyd file by extracting data from the latest dynamic file and solve load flow and confirm. Before running model validation studies, a mini-base case representing power plant conditions just prior to a disturbance is created. PPMV includes an automated mini-state estimation routine which sets up power plant initial condition using SCADA unit status information and PMU bus voltage, and active and reactive power. The model validation process is to play-in the recorded voltage and frequency of the disturbance and calculate real and reactive power using GE PSLF simulation tool.
2. PPMV Application Model Validation Setup 11 An infinite-bus model was developed and implemented in General Electric PSLF program. The model injects recorded bus voltage and frequency in dynamic simulations. The infinite bus is modeled with a large synchronous machine with fast-responding exciters and governors. Recorded bus voltage and frequency are input as references for the governor voltage regulator and governor respectively. If the turbine-governor model is correct, the simulated power should be very similar to the recorded power for events of system frequency excursions
2. PPMV Application Validation Overview - GE PSLF Simulations Inject Recorded Voltage and Frequency Compare Recorded and Simulated Power: MW and MVAR ~ Disturbance playback is a standard feature in PSLF
2. PPMV Application PPMVa_SetBaseCase_v1b.p Power Flow Template (plant.sav) SCADA Data File: SCADA_Plant_Event. dat Event Data File: PMU_Plant_Event.csv PSLF - Mini State Estimator Powerflow File: PLANT_EVENT.sav 13
2. PPMV Application PPMVa_SetBaseCase_v1b.p Purpose: Create a validation base case with initial conditions matching those prior to a disturbance Pre-requisites: A template file with power flow model (*.sav) A disturbance data file compatible with play-in format (*.csv) A SCADA file with generating unit status and loading (*.dat) Result A powerflow file with initial conditions matching those during the event (*.sav) 14
2. PPMVa_SetBaseCase_v1b.p 15 Powerflow case with kv, MW, MVAR at POI matching initial conditions of disturbance record EPCL is setup for one facility - one disturbance
2. FRresponse_v1r.xls Event on 03-14-2013 at 18:14 mdt Plot Function FREQUENCY 60.02 60 59.98 59.96 59.94 59.92 59.9 59.88 18:10 18:11 18:12 18:14 18:15 18:17 BROWNLEE UNIT 5 MW 178 176 174 172 170 168 18:10 18:11 18:12 18:14 18:15 18:17 16
2. PPMV Application PPMVa_RunValidation_v1b.p Power Flow File: PLANT_EVENT.sav Plant Dynamic Data: PLANT.dyd PSLF Channel File: PLANT_EVENT. chf Event Data File: PMU_PLANT_EVENT. csv 17
2. PPMV Application PPMVa_RunValidation_v1b.p Purpose: Perform play-in simulation of a disturbance event Pre-requisites: A powerflow file with initial conditions matching those during the event (*.sav) A disturbance data file compatible with play-in format (*.csv) Dynamic data file with a power plant model (*.dyd) Result Channel file with disturbance data (*.chf) 18
2. PPMVa_RunValidation_v1b.p 19 Validation Comparison of Model to Disturbance Recording EPCL is setup for one validation run of one facility
2. Minimum File Requirements for Play-In in PSLF Input Files Powerflow case representing disturbance I.C. (*.sav) Dynamics data (*.dyd) Disturbance data in PSLF Play-In format (*.txt, *.csv) EPCL that calls the PSLF Play-In Functions (*.p) Output File 20
3. IPCO Tools: Modified FRresponse_v1r.xls 21
3. IPCO Tools: Plot Macro 22
3. IPCO Tools: *.csv Macro Separate Tab for each unit with disturbance data in PSLF Play-In format Macro writes a (*.csv) file to the specified working directory for each unit 23
3. IPCO Tools: *.dat Macro Separate Tab with SCADA Initial Conditions Data for each unit Macro writes a (*.dat) text file to the specific working directory with bus number, bus name, base kv, ID, status, generator kv, MW, MVAR, and baseload flag status data for each unit that was on-line during the disturbance 24
3. IPCO Tools: Set Base Case Batch (*.p) Macro 25 Macro writes a (*.p) text file containing the mailbox variables called by the Set Base Case batch EPCL Only writes records for units that were on-line during the disturbance
3. IPCO Tools: Run Validation Batch (*.p) Macro 26 Macro writes a (*.p) text file containing the mailbox variables called by the Run Validation batch EPCL Only writes records for units that were on-line during the disturbance
3. IPCO Tools: Get Plot Data Batch (*.p) Macro 27 Macro writes a (*.p) text file containing the mailbox variables called by the Get Plot Data batch EPCL Only writes records for units that were on-line during the disturbance
3. IPCO Tools: SetBaseCase_PI_FR_batch.p Template File (*.sav) 28 Disturbance Data File (*.csv) SCADA I.C. File (*.dat) PSLF EPCL to Match Boundary Conditions (*.p) Disturbance Case (*.sav)
3. IPCO Tools: RunValidation_PI_FR_batch.p Disturbance Case (*.sav) 29 Disturbance Data File (*.csv) Dynamics Data File (*.dyd) PSLF Play-In (*.p) Channel File (*.chf)
3. IPCO Tools: Create Validation Files Macro 30
3. IPCO Tools: GetPlotData_PI_FR_batch.p Channel File (*.chf) SCADA I.C. (*.dat) PSLF Plot (*.p) Tab Delimited Text File (*.txt) 31
3. Play-In process using developed Tools 32
33 3. Desired Play-In Validation Tool Features Batch processing capability for validation multiple units Ability to easily process multiple events Retain program structure similar to ALLDYNS batch processor Query PI Data and plot disturbance records for all units Generate disturbance record files in PSLF Play-In format Generate SCADA Initial Conditions files for each generator Generate Powerflow files that reflect I.C. for each generator Create tab delimited text files from channel files for each validation run for external plotting in MATLAB Ability to re-run the process with modified dynamics data
4. Play-In validation examples using PI data A List of WECC Frequency Events used to perform Model Validation at IPCO Event 03-14-2013 @ 1814 mdt (59.89 Hz) Event 03-31-2013 @ 1905 mdt (59.90 Hz) Event 04-01-2013 @ 0908 mdt (59.84 Hz) Event 04-29-2013 @ 1148 mdt (59.86 Hz) Event 05-07-2013 @ 1137 mdt (59.88 Hz) Event 05-22-2013 @ 1621 mdt (59.88 Hz) Event 05-30-2013 @ 1621 mdt (59.70 Hz) Event 08-03-2103 @ 0351 mdt (59.88 Hz) Event 08-13-2013 @ 1630 mdt (59.89 Hz) Event 08-18-2013 @ 1704 mdt (59.82 Hz) 34
35 4. Examples
36 4. Examples
37 4. Examples
4. Examples Red = Recording Blue = Simulation 38 Modified hyg3 Ki from 0.35 to 3.25 Added lcfb1 model
4. Play-In Validation Process 10 Frequency Events (2013) Step 4 Post Process Results Create Validation Report 39
4. Cautions 40 SCADA Problems Noise, Poor Resolution PI update rate and dead band - Sampling intervals can be as high as 10 s Aliasing can result in incorrect conclusions if the sampling frequency is not sufficiently high. The minimum of 4-s resolution must be maintained. Another problem in SCADA could be the megawatt threshold before a new number is recorded. In some cases, the threshold is set as high as 10 MW, creating a dead band effect, exceeding the governor response during recordings of frequency disturbances. SCADA thresholds for unit and plant power recordings must therefore be set to appropriate lower threshold levels
5. Lessons Learned Approach works for Governor validation Bigger events to get outside of input data dead bands provided better matches Good for identifying undesired control behavior Good for identifying units represented with sustained frequency response but actually operate under load control 41
5. Future Work Develop automation tools for creating validation reports Expand validation tool set for compatibility with PMU database Expand validation tool set for compatibility with DFR records Work with Generator Owners to identify areas for improving model performance Identify how the developed PSLF Play-In tools can be incorporated into the data validation process used to meet the proposed requirements of NERC MOD-033-1 Steady-State and Dynamic System Model Validation 42
Questions? 43