Application of Solid-State Circuit Breaker in Selective Relay Protection of Marine DC Distribution System

DC distribution electric propulsion is the trend of ship power development in the future. The problem of selective relay protection for bus-connected equipment has not been properly solved, which directly threatens the safety of navigation. Therefore, on the basis of analyzing the short-circuit fault principle of marine DC distribution system and the simulation and experimental verification, a relay protection scheme using solid-state circuit breaker instead of the bus-tie fast fuse is proposed. The scheme uses high-speed interruption to isolate the impact of fault on bus voltage on the normal side to ensure the continuity of power supply and navigation safety. Finally, the realization method of selective relay protection for DC distribution system and the strategy of power supply recovery after fault are put forward, which meet the requirements of marine power engineering application.