PMU based midterm stability evaluation of wide-area power system

Since the aspect of instability phenomena during midterm is complicated, the stability analysis is significant in order to keep the power system stable. Synchronized phasor angles obtained by the PMU (phasor measurement unit) provide the effective information for evaluating the stability of a bulk power system. This paper proposes a midterm stability evaluation method of the wide-area power system by using the synchronized phasor measurements. Clustering and aggregating the power system to some coherent generator groups, the stability margin of each coherent group is quantitatively evaluated on the basis of the one machine and infinite bus system. The midterm stability of a longitudinal power system model of Japanese 60 Hz systems constructed by the PSA (Power System Analyzer), which is a hybrid-type power system simulator, is practically evaluated using the proposed method.