Fuzzy logic based contingency analysis

This paper deals with the contingency selection problem in power systems. The main objective is to explore the application of fuzzy logic on contingency selection for voltage ranking. It shows how fuzzy logic could be used to tune both the weighting factors and the exponent index and hence reduce the masking effect. Firstly, the post-contingent voltages are expressed in fuzzy logic. Secondly, fuzzy logic rules are applied to rank the contingencies. There are two types of fuzzy control rules: Mamdani- and Sougeno-rules. The first part of this paper investigates the use of the Mamdani method for voltage ranking. The second part examines the application of Sougeno method to voltage ranking. Numerical results for the IEEE-30 bus test system are given. At the end of this paper there is a comparison study between these methods. It is found that the Sougeno method is much more flexible, suitable, and gives better results than the Mamdani method.