Parameter Matching of DC Reactor and DC Circuit Breaker in Multi-terminal DC Distribution System

Compared with the two-terminal distribution system, the multi-terminal system has the characteristics of high flexibility and reliability. However, the fault analysis and protection are more complex. This paper analyzes the generation mechanism of short-circuit current of half-bridge converter, calculates the fault current of three-terminal ring network, and proposes a parameter matching method of DC circuit breaker and current limiting reactor which lays a foundation for the protection of the DC line. A three-terminal DC loop network is built in MATLAB to verify the correction of the parameter calculation method by simulation. The DC circuit breaker cooperated with the current limiter can isolate the fault within the breaking capacity, and the system voltage can recover rapidly after the fault is isolated.