Syncrophasor measurement based small signal stability assesment using FFT-CWT approach in Japan-Campus-WAMS

A sequence of Fast Fourier Transform (FFT) and Continuous Wavelet Transform (CWT) are elaborated to deal with Phasor Measurement Unit (PMU) data. FFT algorithm identifies the center of oscillation and filters the signal then Complex Morlet (CM) Continuous Wavelet transforms it to the three dimensional (3-D) representation for further analysis. Damping ratio is estimated by demodulating signal slices at the ridge of signal using a linear regression approach. To verify the authenticity, the Two Area Four Machine (TAFM) system is exploited by simulating a step by step change in the load and then its damping ratio is estimated using the proposed approach and Power System Analysis Toolbox (PSAT) which is based on Eigen Value analysis. The results show both methods are fitting each other. Finally, a real PMU data from Japan CampusWAMS are analyzed.