Improvement of the Evaluation of the Wide Area Power System Stability Based on Multiple Synchronized Phasor Measurements with Observation Sites Changed

Abstract

This paper presents a method for monitoring the power system stability based on wide area phasor measurements. The authors have developed a method for detecting inter-area low-frequency modes from measured small oscillations associated with the load fluctuation by approximating filtered oscillations as a simplified oscillation model. The advantage of this method is that steady state phasor fluctuations are available to evaluate the stability of the power system. In this paper, another type of the filter based on the FFT analysis is developed for improving the accuracy of identified eigenvalues with observation sites changed. The method based on the FFT-based filtering is also applied to extract low-frequency oscillations from phasor data of one observation site. Some numerical analyses demonstrate the effectiveness of the method by using phasor dynamical data obtained by a power system simulation package and the phasor measurement system developed in Japan.