ANOTHER VERSION OF THE EXTENDED EQUAL-AREA CRITERION APPROACH TO TRANSIENT STABILITY ANALYSIS OF THE TAIPOWER SYSTEM

Another version of the extended equal area criterion (EEAC) method for fast transient stability analysis is presented. First, an efficient method of identifying the critical cluster by a two-step gap-ranking process of rotor angles is devised to decompose the multimachine system into two coherent groups. Then, the recently developed EEAC method is revised to circumvent some of its major difficulties. The main appeal of the presented method lies in that the empirical corrective factors compensating for the truncation error in the Taylor series expansion are completely eliminated. Moreover, the iterative procedure involved in evaluating the critical clearing angle can be precluded. Another attractive feature to be emphasized is the considerable curtailment in solution time in identifying the critical cluster. Finally, the proposed method is tested on the Taipower system, which is the only power system in Taiwan. The results obtained agree rather well with those from the conventional step-by-step method. It is significant that the presented method is superior to the most prevailing direct method, the potential energy boundary surface method, in its rapidity with comparable accuracy.