High-Performance and Economical Forced Resonant DC Circuit Breaker: Topology, Design, and Development

A dc circuit breaker (DCCB), which can interrupt a fault current, is the key equipment in a voltage source converter-based high-voltage dc (VSC-HVDC) transmission system. However, the existing DCCBs cannot balance economy and high reliability, thus preventing their large-scale application. This article proposes a new type of forced resonant mechanical circuit breaker (FR-MCB) that can generate an unlimited number of zero crossings to meet the requirements of low cost and high performance. To improve the performance of interrupting a fault current, a control strategy is proposed to offset the adverse effects of the delay in switching the insulated-gate bipolar transistor (IGBT) on and off. Moreover, the parameter optimization method is studied to further reduce the cost of the FR-MCB. Finally, an 80-kV/10-kA prototype with high reliability and a much lower cost than those of the existing hybrid circuit breaker (HCB) and MCB schemes is developed, providing a new technical route for improving the economy of dc fault protection.