Fuzzy fault tree analysis of a power transformer

Power transformer is an essential and integral part of any power system. Failure of power transformer affects the working of entire system. Since failure probability is smaller as compared to success, it is easier to carry out the failure analysis for estimating the success probability. However, past failure information results in short term failure probability which does not provide reliable information about the future behavior of the system. In order to overcome the uncertainty in the analysis, expert fuzzy number based fault tree analysis may be adopted for estimating the failure probability of the transformer. In this study, fuzzy fault tree approach has been described and applied for failure probability estimation of a distribution transformer. The results are compared with Conventional Fault Tree Analysis. Further, the basic failure events are ranked according to Fuzzy Importance Index (FII). This will help the decision maker to prioritize the components for repair and attention so as to improve the reliability of the system.