A systematic method and its near-real time application to analyze the Low Frequency Oscillation based on WAMS

In this paper, a systematic method is presented to research the Low Frequency Oscillation (LFO) in bulk power system based on the Wide Area Measurement System (WAMS). This method contains two different approaches: the nonlinear analysis method (NAM) and energy analysis method (EAM). The NAM extracts the oscillatory parameters and oscillation mode based on the nonlinear viewpoint of each single measured signal and the EAM analyzes the LFO phenomena from the energy aspect based on the ensemble measurement matrix. Two methods work as a complementary manner and their calculated results check each other. The near-real time application of proposed method is described based on the instantaneous computation ability of NAM and the recursive relationships of the covariance matrix of ensemble measurement matrix. The actual measured data from WAProtector is utilized to evaluate the feasibility and validity of the proposed method.