Research on reliability evaluation method of DC circuit breaker based on Markov model

摘要

Natural commutation hybrid DC circuit breakers integrate the low loss of mechanical circuit breakers and the fast switching speed of solid-state circuit breakers. Its overall reliability determines the success or failure of the control of the current distribution of the DC distribution network. In this paper, the Fault Tree was used to analyze the basic components that caused the circuit breaker to fail, based on the topology of hybrid DC circuit breaker. The Markov model is introduced into the reliability modeling of hybrid DC circuit breaker to calculate steady state availability, failure rate and mean time between failures. On this basis, k(G) model and Gamma distribution are used to analyze the redundancy of weak components in hybrid DC circuit breakers. Finally, the influence of different redundancy components and different redundancy modes of weak components on the reliability of hybrid DC circuit breakers is analyzed quantitatively. The analysis methods and results can provide a reference for reliability prediction and design of hybrid DC circuit breakers.