Research on Current Limiting Protection Method of Short Circuit Faults in Medium Voltage DC Integrated Power Systems

The problem of short-circuit fault limitation and protection is a big challenge in the development of medium voltage DC integrated power system. The traditional current–time protection principle cannot limit the fast rising short-circuit current, which will have a serious impact on the system. It is an effective protection idea to install fault current limiter in the power system. In this paper, the network structure and basic parameters of a medium voltage DC integrated power system are given, and the short-circuit fault characteristics and protection requirements are analyzed. Then, a protection strategy based on a new liquid metal current limiter is proposed, and the optimal configuration scheme and characteristics of the current limiter are analyzed, thereby achieving fast limitation of short circuit faults and rapid support of bus voltage, significantly reducing the system’s requirements for circuit breaker breaking capacity and speed.