Power system low frequency oscillation monitoring and analysis based on multi-signal online identification

Abstract

The advance in the wide-area measurement system (WAMS) is driving the power system to the trend of wide-area monitoring and control. The Prony method is usually used for low frequency oscillation online identification. However, the identified amplitude and phase information is not sufficiently used. In this paper, the amplitude is adopted to detect the occurrence of the oscillation and to obtain the mode observability of the sites. The phase is adopted to identify the oscillation generator grouping and to obtain the mode shapes. The time varying characteristics of low frequency oscillations are studied. The behaviors and the characters of low frequency oscillations are displayed by dynamic visual techniques. Demonstrations on the “11.9” low frequency oscillation of the Guizhou Power Grid substantiate the feasibility and the validation of the proposed methods.