Dynamic characteristic analysis of power system interarea oscillations using HHT

Utilizing the Hilbert–Huang transform (HHT) analysis techniques, the authors propose a practical method for detection and estimation of interarea oscillations in power systems from a nonlinear and nonstationary perspective. The methodological approach proposed here can analyze local dynamic behaviors and characteristics of nonstationary and nonlinear signals, better reflect the time-varying law of multi modes involved in oscillation process as well as the mutual influences among these modes, and improve the identification ability and processing effect. An initial application to the data acquired through the wide-area measurement system (WAMs) of Guizhou Power Grid in China is presented to verify the ability of estimating the time-varying characteristics inherent to the electromechanical oscillation processes. The preliminary test results prove the potential and feasibility of the proposed method, and suggest that it can be used as one of on-line identification methods in power system.