Global oscillation mode analysis using phasor measurement units-based real data

This study employs the Hilbert-Huang transform (HHT), the wavelet transform (WLT) and the fast Fourier transform (FFT) to analyze the inter-area (global) oscillation characteristics of Western Japan 60 Hz power system. The data are collected from a network of distributed phasor measurement units (PMUs) through a national project called Campus wide area monitoring system (Campus WAMS). In the present paper the Campus WAMS is introduced, and then the recorded phase difference data are analyzed using WLT, FFT and HHT methods, respectively. A comprehensive comparison is performed, and it is demonstrated that HHT offers more flexibility in terms of detailed profile and enough description, which can be beneficial for power system small signal stability analysts following estimation of system low-frequency oscillation. The results could be useful for on-line tuning of power system stabilizers.