Power system fault diagnosis using fuzzy sets for uncertainties processing

Great emphasis has been put into applying expert systems to power transmission system fault diagnosis. However, very few papers deal with the unavoidable uncertainties which occur during operation involving fault location and other available information. This paper proposes a method using fuzzy sets to cope with such uncertainties. A fuzzy expert system is developed, which requires much less memory space to store active databases than those used by conventional expert systems. The fuzzy expert system identifies two basic data sets, S_faultand S_no-fault, using the status of operated and maloperated circuit breakers and relays. It then conducts inference to determine the most likely faulty components and the associated faulty component sequences. Two case studies are given in the paper to demonstrate salient features of the proposed approach