Examination of severe contingencies in a small area of a large composite power system using adequacy equivalents

The quantitative evaluation of the adequacy of a major load point or of an overall power system involves the examination of both generation and transmission facilities. The main task in such an analysis is to consider all those credible outage events which can significantly affect the performance of the network. The number of events which must be examined is dependent upon the intent behind the studies and the adequacy indices being calculated. This may involve a detailed examination of a large number of events involving multiple component outages. The consideration of the required outages, however, is severely restricted in a practical network by the required computation time. This paper presents a new and efficient approach to include the effect of high-level independent outages in a part of a network which utilises an adequacy equivalent developed for the remaining part of the network. The applications and advantages of using the proposed method are illustrated by presenting results for two test systems which are described in the paper.