Reliability Analysis of Relay Protection Based on the Fuzzy-Markov Model

Abstract

Relay protection and safety device are regarded as the sentry of safe and reliable operation of the power grid. It plays a very important role in the power grid, and can determine whether the normal operation of the power system. This article considers the influence of the fuzzy uncertainty of relay protection failure rate to power system on the basis of Markov model, and researches the dynamic fault tree analysis method in the case of fuzzy failure parameter. A dynamic fault model has been built. The triangular fuzzy numbers are used to express the failure rate of the components and system, after which the fuzzy Markov model has been established based on the dynamic fault tree model obtained before. The fuzzy reliability curve and fuzzy failure probability on given degree of membership could be obtained. Finally, the fuzzy Markov model based dynamic fault tree analysis method is used for reliability modeling and analysis of relay protection. The results show that this method can conduct reliability modeling and quantitative assessment effectively for systems which have dynamic failure characteristics and uncertainty of failure rate.