PMU Emulator for Power System Dynamics Simulators A. Srivastava, P. Banerjee, H. Lee, Smart Grid Demonstration and Research Investigation Lab (SGDRIL) Energy System Innovation center, Washington State University Evangelos Farantatos and M. Patel Electric Power Research Institute Contact: anurag.k.srivastava@wsu.edu JSIS October 2017

Outline Introduction to PMU based model validation Motivation and goals Frequency based Point of wave based PMU Emulator interface/software PMU Emulator Development Modulation Test Step Response Test Benchmark Test of PMU Emulator Fault case Parameter estimation Online small signal stability estimation Results & Application Summary

Introduction to PMU based model validation 6/27/2018 Introduction to PMU based model validation Application of PMU measurements for model validation: Line parameter estimation Power Plant (Generator) Model Validation Renewable Energy Models SVC and STATCOM HVDC Load Model

Outline Introduction to PMU based model validation Motivation and goals Frequency based Point of wave based PMU Emulator interface/software PMU Emulator Development Modulation Test Step Response Test Benchmark Test of PMU Emulator Fault case Parameter estimation Online small signal stability estimation Results & Application Summary

Motivation and goals Phasors from Dynamic simulator and PMU cannot be compared directly due to following reasons: • The attenuation of the digital filters in the PMU. • The delay caused by the digital filters in the PMU. • The length of the data window resulting averaging effect. • Time stamping the phasors at appropriate window position.

Comparison of phasor output from Dynamic Simulator and PMU Motivation and goals PMU Emulator provide additional compensation and interface such that phasors from dynamic simulators and PMU can be compared Comparison of phasor output from Dynamic Simulator and PMU

Outline Introduction to PMU based model validation Motivation and goals Frequency based Point of wave based PMU Emulator interface/software PMU Emulator Development Modulation Test Step Response Test Benchmark Test of PMU Emulator Fault case Parameter estimation Online small signal stability estimation Results & Application Summary

PMU Emulator Development Frequency based (FB) compensator for PMU Emulator Compensating for filtering effect in frequency domain for magnitude and phase response

PMU Emulator Development Point on wave based (POW) compensator for PMU Emulator The reconstructed POW signals are multiplied with synchronously generated sine and cosine signal from a quadrature oscillator. The two heterodyne signals are filtered using P or M class FIR filter Transformed to polar form and time stamp at the center of the data window. Magnitude and angle coefficients for POW mode

PMU Emulator Development Error Metric Phasors from the PMU are considered as the base value and the error of the PMU Emulator is reported w.r.t the phasors obtained from PMU Configuration I is PMU Emulator configured in FB mode Configuration II is PMU Emulator configured in POW mode with one cycle approximation Configuration III is PMU Emulator configured in POW mode with quarter cycle approximation.

PMU Emulator Development PMU Emulator interface/software

Outline Introduction to PMU based model validation Motivation and goals Frequency based Point of wave based PMU Emulator interface/software PMU Emulator Development Modulation Test Step Response Test Benchmark Test of PMU Emulator Fault case Parameter estimation Online small signal stability estimation Results & Application Summary

Benchmark Test for PMU Emulator Modulation Test Errors for modulation test (15 cycle of data window and Hamming function)

Benchmark Test for PMU Emulator Step Response Test: Magnitude step from 1pu to 0.6pu and phase step from 0 deg to 20 deg. The magnitude step occurs at 1s and phase step occurs at 1.4s. Errors for modulation test (15 cycle of data window and Hamming function)

Outline Introduction to PMU based model validation Motivation and goals Frequency based Point of wave based PMU Emulator interface/software PMU Emulator Development Modulation Test Step Response Test Benchmark Test of PMU Emulator Fault case Parameter estimation Online small signal stability estimation Results & Application Summary

Results & Application Fault case   Generator 1 Generator 2 MVA 615 100 Inertia 5.148 0.3 Damping 2 0.1 Tdo’ 7.4 3.2 Machine parameters: Two machines are used with following features. Machine 1 is very heavy as compared to Machine 2, so any disturbance in the system results in large oscillations to Machine 2 with respect to Machine 1 The fault is created at Bus 3 for 100ms and 0.1pu fault level. The system kV is 69kV, so fault impedance is 4.761ohm. The clearing of fault results in oscillation in the system of around 2.1Hz.

Results & Application Fault case Voltage TVE for Fault scenario

Results & Application Fault case Current TVE for Fault scenario

Results & Application Parameter estimation Model Parameter Estimation Framework

Magnitude Step response for Model Parameter Estimation Results & Application Parameter estimation Gain and time constant are unknowns while other parameters are known Magnitude Step response for Model Parameter Estimation

Results & Application Parameter estimation

Results & Application Online small signal stability estimation Eigenvalues shows that PMU Emulator is closer to PMU as compared to dynamic simulator

Outline Introduction to PMU based model validation Motivation and goals Frequency based Point of wave based PMU Emulator interface/software PMU Emulator Development Modulation Test Step Response Test Benchmark Test of PMU Emulator Fault case Parameter estimation Online small signal stability estimation Results & Application Summary

6/27/2018 Summary The FB mode of PMU emulator linearly approximates the non-linear behavior of the PMU, while POW mode of PMU emulator mimics the non-linear behavior of the PMU. PMU Emulator tested with modulation test case and step input test case. The magnitude and phase response of the POW mode of PMU emulator is closer to the PMU response. The quarter cycle approximation of POW mode PMU Emulator performs better than the one cycle approximation of POW mode for modulation test case. However, the step change test does not result in much difference of the two POW modes. The voltage and current TVE are plotted for fault scenario. POW mode with one cycle approximation performs better than FB mode. The improvement in model parameter estimation and online small signal stability assessment using PMU Emulator is also demonstrated. Template C Plain-crimson-bright

Contact: anurag.k.srivastava@wsu.edu 6/27/2018 Contact: anurag.k.srivastava@wsu.edu Template I-Aqua curve

Backup Slides Voltage Angle response for Fault scenario

Backup Slides Current Angle response for Fault scenario

Backup Slides Voltage Magnitude response for Fault scenario

Backup Slides Current Magnitude response for Fault scenario

Backup Slides

Backup Slides PMU Emulator USE CASES: Online small signal stability assessment The estimation of the modes for small signal stability assessment using PMU measurements consists of following steps [*]: • Select time interval for analyzing phasor data after the fault clearing. • Buffer voltage phase angle and frequency of the reference bus and the target bus  for the selected time interval. • Construct the Hankel matrix based on the measurement. • Construct the input matrix for the control action (zero for post fault condition) and stack below the state transition matrix to form augumented matrix. • Perform LQ decomposition of the augmented matrix. • Select the non zeros lower right partition of the LQ decomposition • Perform singular value decomposition of the non zeros lower right sub-matrix from previous step. • Construct the extended observability matrix using the span of the column space of non zeros lower right sub-matrix. • Estimate the state transition matrix from the extended observability matrix. • Calculate the eigenvalues of the state transition matrix. The real part of the eigenvalues is the damping and imaginary part is the frequency of the particular mode. [*] P. Chusovitin and A. Pazderin. Small-signal stability monitoring using pmu. In 2014 IEEE International Energy Conference (ENERGYCON), pages 267–272, May 2014.