Lessons Learned in Model Validation for NERC Compliance

Lessons Learned in Model Validation for NERC Compliance usa.siemens.com/digitalgrid

NERC Modeling, Data, and Analysis MOD 025 2: Generator Real and Reactive Power Capability Demonstration MOD 026 1: Verification of Models for Generator Excitation Control Systems MOD 027 1: Verification of Models for Turbine/Governor and Load Control Functions, including validation of turbine droop and determination of governor s deadband MOD-033-1: Steady-State and Dynamic Power System Model Validation Page 2

Unit Size for NERC Model Validation Requirement (MVA) ERCOT Eastern Interconnection WECC Individual Unit Plant Individual Unit Plant Individual Unit Plant MOD-25-2 >20 >75 >20 >75 >20 >75 MOD-26-1 >50 >75 >100 >100 >75 >75 MOD-27-1 >50 >75 >100 >100 >75 >75 Page 3

Siemens PTI Services Onsite technical assistance for performing the tests Field tests data processing Model validation (PSS E/PSLF) Verification of generator OC excitation curve and generating unit inertia constant Adjustment of controllers parameters AVR and PSS tuning Over- and Under-excitation limiter adjustment V/Hz limiter adjustment Development of user-written models Page 4

MOD-025-2 Generator Tests Estimated and Operating capability curve (D-curve) Page 5

MOD-025-2 Generator Tests Measurements: Active & reactive power, voltage at unit terminals (point A) Active & reactive power, voltage at the high voltage side of the GSU (point F) Active & reactive power through the high voltage side of the auxiliary transformer (point B) Voltage at the low voltage side of the tertiary winding (point C) Active and reactive power at the high voltage side of the GSU of the other units (point D) Page 6

MOD-026-1 Generator Excitation Control System Model Verification Open-circuit dynamic response calibration Interconnected dynamic performance calibration Validate model parameters by comparing field test records against current PSS E or PSLF dynamic models Page 7

MOD-026-1 Generator Excitation Control System Model Verification Open-circuit dynamic response calibration Interconnected dynamic performance calibration Validate model parameters by comparing field test records against current PSS E or PSLF dynamic models Page 8

MOD-027-1 Turbine/Governor and Load Control Functions Model Verification Validation of the speed governor response for an on-line perturbation test with synthetic speed signal of ±0.2Hz Page 9

Governor Modeling Improvements for Stability and Frequency Response Studies MISO Experience usa.siemens.com/digitalgrid

Result of NERC MOD-033 System Model Validation performed by MISO MISO uses the Eastern Interconnect Wide Model for Transient Stability Analysis. These models predicts system frequency response settling at a higher value. This difference between the simulated and the PMU recording is due to lack of deadband in the governor model. This modeling issue has been a known for a long time. Frequency in Hz 60.0200 60.0000 59.9800 59.9600 59.9400 59.9200 59.9000 Frequency nadir differs 59.8800 59.8600 Gen trip simulated at 0.5 sec Settling frequency is optimistic. Frequency with Current Models PMU Synchrophasor data Frequency comparison on 345 kv Bus near the generator 0.00 0.28 0.55 0.83 1.09 1.37 1.64 1.92 2.19 2.47 2.74 3.02 3.29 3.57 3.84 4.12 4.39 4.67 4.94 5.22 5.49 5.77 6.04 6.32 6.59 6.87 7.14 7.42 7.69 7.97 8.24 8.52 8.79 9.07 9.34 9.62 9.89 10.17 10.44 10.72 10.99 11.27 11.54 11.82 12.09 12.37 12.65 12.92 13.20 13.47 13.75 14.02 14.30 14.57 14.85 15.12 15 40 TIme in sec Page 11

Governor Dadband Modeling Improvement 14 governor models with deadband blocks were released in PSS E versions 33.10 and 34.2 MISO did extensive testing of these new models on the Eastern Interconnection with very encouraging results IEEEG1* asymmetrical dead-band IEEEG1SDU* Page 12

MISO Test Results of 2020 Summer Dynamic case with New Governor Models, compared to Real Time Data 60.010 60.000 59.990 Green trace represents base case with current governor models. Incorrect model prediction. 59.980 59.970 Hz 59.960 59.950 PMU : Frequency at 345 kv Bus near Fermi Generating Plant Unit Frequency, New Governor Type, 2020SUM Frequency, Base Model, 2020SUM 59.940 59.930 59.920 Settling frequency in simulation (red trace) closer to Real time data (purple trace), which is critical for any frequency related studies. Note :Some difference expected as case represents an out year scenario, not the actual system condition pre-event. 0.0 0.4 0.7 1.1 1.4 1.8 2.2 2.5 2.9 3.2 3.6 4.0 4.3 4.7 5.0 5.4 5.8 6.1 6.5 6.9 7.2 7.6 7.9 8.3 8.7 9.0 9.4 9.8 10.1 10.5 10.8 11.2 11.6 11.9 12.3 12.7 13.0 13.4 13.7 14.1 14.5 14.8 15.2 15.6 15.9 16.3 16.6 17.0 17.4 17.7 18.1 18.5 18.8 19.2 19.6 19.9 seconds Page 13 *MISO Dynamics model Wind at 15.6% of Pmax in MISO

Power Plant Model Validation using PSS E Playback Model usa.siemens.com/digitalgrid

PSS E Playback Model PLBVFU1 Overview The PLBVFU1 model plays back a known set of voltage and frequency signals The PLBVFU1 model acts as a generator model (with no excitation system or turbine-governor models) The played-in voltage and frequency signals must be included in a data input file Page 15

PSS E Playback Model Playback Model for Voltage Signal Page 16

PSS E Playback Model Playback Model for Frequency Signal Page 17

PSS E Playback Model Playback Model Example Test System Unit to be tested Playback generator Page 18

PSS E Playback Model Playback Model PMU data vs. PSS E simulation results Page 19

Contact Us Carlos Grande-Moran Principal Consultant Siemens Power Technologies International E-mail: carlos.grande@siemens.com Dinemayer Silva Staff Consultant Siemens Power Technologies International E-mail: dinemayer.silva@siemens.com usa.siemens.com/digitalgrid Page 20