Fuzzy logic based MW contingency ranking against masking problem

The main objective of an electric power system planning and operation is to maintain the system security while respecting certain constraints imposed on the system. As a framework of security, it is important to investigate the influence of potential failure states on the system performance in advance. Contingency ranking quantifies the severity of each outage with a scalar performance index, by which all possible contingencies can be ranked. Low order performance indices are preferred for the sake of computational efficiency. However, they cannot succeed in accurate ordering because of masking effect. This paper presents a fuzzy logic based MW contingency ranking algorithm for line outage contingency analysis, which minimizes the masking effect. Following the presentation of theoretical basis, the proposed algorithm is applied to several test systems. The concordance of the resulting rankings and the actual rankings are tested with several statistical quantities