Design and Development of A Hybrid DC Circuit Breaker for 380V DC Distribution System

Design and operation of a hybrid DC circuit breaker for 380V DC distribution system is presented in this work. A hybrid DC circuit breaker offers reduced on-state loss compared to its full solid-state alternative while ensuring arc-free, fast current interruption. Power electronic converters’ current limiting capability during overload in a DC distribution system can be leveraged to accommodate slow response time of mechanical switch compared to its solid-state counterpart to increase system efficiency during normal operation. A hybrid circuit breaker for a 380V/10kW system, along with its control and device thermal models, is implemented in PLECS. Operational and thermal simulation results are provided to validate safe breaker operation. Additionally, a compact hybrid DC circuit breaker design is presented and a prototype has been fabricated. Performance of the constructed hybrid DC circuit breaker has been evaluated experimentally for a scaled down 380V/5kW DC system to demonstrate very low on-state loss and arc-free current interruption.