A Novel Forced Resonant Mechanical DC Circuit Breaker by Using Auxiliary Oscillation Switch for Zero-Crossing

A low-cost mechanical circuit breaker (MCB) is an important solution in the field of dc breaking. However, the zero-crossing points in the breaking process of the existing MCBs are either insufficient in number or slow in generation, which limits the breaking performance of MCBs. This letter proposes a novel forced resonant MCB (FR-MCB). A large number of zero-crossing points can be generated in a short time by utilizing a resonant circuit and a power electronic-based auxiliary oscillation switch. Thus, the FR-MCB can exhibit more reliable and faster breaking performance while maintaining the low cost. After the detailed analysis of current oscillation and breaking process in the FR-MCB, a prototype experiment of up to 10 kV/8 kA is conducted to verify its feasibility.