PSSE Playback Model Validation with PMU Data Damien Sommer, P.E. Senior Transmission Planning Engineer

ATC Footprint

DATC Transmission in WECC

PSSE Playback Feature Model will be available in PSS®E version 34.1 The model is supplied as part of PSS®E installation; therefore, use of this model will not require compilation and link. For version 33 users a .dll file can be downloaded from the Siemens PTI website

Time, voltage, frequency PSSE Playback Feature This model plays back a known set of voltage and frequency signals. The PLBVFU1 model acts as a generator model. In using this generator model, do not attach an AVR or governor model to the machine associated with the PLBVFU1 model. The played-in voltage and frequency signals must be described in a file as shown below, with each sample described in a separate record and the values in each line separated by spaces or commas: Time, voltage, frequency

PSSE Playback Feature The file containing the measurement has to be supplied in a file with an extension “.plb”. The file name (without the “.plb” extension) has to be less than or equal to 12 characters long for PSSE v 34 and less than or equal to 2 characters for PSSE v 33. This file has to exist in the working folder. If the “plb” file is not found, the PLBVFU1 model will keep the internal voltage and frequency fixed at the initial value (i.e., the playback feature will be ignored).

PSSE Playback Feature The voltage signal which is played back is the internal (Thevenin) voltage of the playback generator. The ZSORCE of the generator used to represent the PLVFBU1 model should be non-zero. The sampled voltage and frequency values may be smoothed via a first order block with time constants Tv (for voltage signal) and Tf (for frequency signal).

PMUs On ATC Transmission System 21 PMUs on high side of GSUs: 9 Coal 4 Combined Cycle Gas 2 Nuclear 4 Wind Farms 2 HVDC terminals

Python Script v1 – User Input Data baseCase = ‘Large_Coal_Unit_v33_20151008' plbfile = 'AA' dyrfile = 'Large_Coal_Unit_v33_20151008' csvoutfile = ‘Large_Coal_Unit.csv' testGenNum = 700001 testGenID = ‘1' equivFrom = 700000 Vnom = 345

Python Script v1 – Mini State Estimation Retrieve initial conditions recorded by PMU at POI Sets the initial conditions in the simplified case to those observed by the PMU at the POI Save case with initial conditions as temp.raw

Python Script v1 – Run and Output Run simulation using PMU data to define playback unit response Creates channel files for voltage, frequency, active power and reactive power at POI bus where PMU was recording Outputs a .csv file with data for each channel

Playback Simulation Process place PMU data .csv file, PSSE files, Python script in event folder Save .csv file as .plb file Run script (takes about 30 seconds)

Example 1: Large Coal Unit, Line Faults Simplified Model Used in Playback Runs:

Demonstration

Example 1: Large Coal Unit, Line Faults Event 1

Example 1: Large Coal Unit, Line Faults Event 2

Example 1: Large Coal Unit, Line Faults Event 3

Example 1: Large Coal Unit, Line Faults Event 4

Example 2: Large Coal Unit, Large Unit Trip Event 1 If monitored unit is not dispatched to PMAX governor PMAX value in .dyr file will likely have to be updated Values in MMWG case Unit MVA = 825 PMAX = 634 IEEEG1 governor model PMAX (pu on machine MVA rating) = 0.847 (~700/825) PGEN = ~500 MW during this event

Example 2: Large Coal Unit, Large Unit Trip Event 1, PMAX = 0.847

Example 2: Large Coal Unit, Large Unit Trip Event 1, PMAX = 0 Example 2: Large Coal Unit, Large Unit Trip Event 1, PMAX = 0.606 (Pgen / MVA)

Example 2: Large Coal Unit, Large Unit Trip Event 1, PMAX = 0.615

Example 2: Large Coal Unit, Large Unit Trip Event 3, Oscillations

Example 3: Combined Cycle Plant, Large Unit Trip – CT1 First Pass

Example 3: Combined Cycle Plant, Large Unit Trip – CT1 First Pass If using actual bus numbers and reusing the same python script check channel numbers PSSE orders model information by bus number ascending order If gen bus number is larger than POI bus number in one raw file but smaller than POI bus number in another raw file your exported channels will be different

Example 3: Combined Cycle Plant, Large Unit Trip – CT1 Second Pass

Example 3: Combined Cycle Plant, Large Unit Trip – CT2

Example 3: Combined Cycle Plant, Large Unit Trip – ST

Example 3: Combined Cycle Plant, Line Fault – CT1

Example 3: Combined Cycle Plant, Line Fault – CT2

Example 3: Combined Cycle Plant, Line Fault – ST

Example 4: ~300 MW Coal Unit Line Fault Event

Example 5: ~300 MW Coal Unit Trip of 850 MW Unit in Remote Location

Example 6: ~600 MW Nuclear Unit Trip of 1200 MW Unit in Remote Location

Example 7: ~600 MW Nuclear Unit 345-kV Line Fault

Harder Configurations to Validate: Gas Plant with PMU at Shared POI

Harder Configurations to Validate: Gas Plant with PMU at Shared POI PMU is on the POI bus and thus captures the output of both units simultaneously Version 2 Python Script required Investigate PI Historian data on the two units and set one plant P and Q output to initial output Fix the P and Q of the second unit with state estimation in in the python script

Harder Configurations to Validate: Wind Farm with Multiple Var Sources

Harder Configurations to Validate: Wind Farm with Multiple Var Sources PMU is on 138-kV Bus, there is a DSTAT model and switched shunt device on the 34.5-kV bus Cap Bank on unit bus is supposed to be manual set in the model based on wind unit output PI Historian data will have to be pulled to find starting points for wind unit, switched shunts and DSTAT model

Conclusion Still early in process of validating units but so far we haven’t found any events where the models matched reality very well This is a very important tool to help get us to better models More work is needed with GOs to improve models

Contact Information Damien Sommer, P.E. (262) 506-6949 dsommer@atcllc.com

Questions