Development of Solid State Circuit Breakers for 380V DC Microgrid Protection

摘要

The DC distribution system is becoming an appealing research spot in recent years and has also been investigated and applied in DC shipboard, airplane system, telecommunication system, DC buildings and DC data centers, etc. However, the protection of DC system is facing several harsh issues including the arcing phenomenon at the time of disconnection, the large and fast inrush current and discharge current generated by distributed capacitance on DC bus, etc. The traditional Miniature Circuit Breaker (MCB), Molded Case Circuit Breaker (MCCB) and fuses are not the qualified candidates for dealing with these new issues. A new protection architecture is proposed for 380V DC Microgrid protection. Three different equipment are proposed, analyzed, developed and tested for different current rating in this paper. A hotswappable outlet is designed with zero standby power to eliminate the arcing with solid-state devices. Moreover, it is used to isolate the downstream fault with current limiting capability. Then a solid-state node circuit breaker is created with paralleled devices. Interleaved hiccup startup and transient junction temperature monitoring are presented. Finally, a hybrid branch circuit breaker is designed for the high current application. A novel driving strategy based on mechanism analysis is considered and tested for performance enhancement. Besides, multiple solid-state devices are investigated and selected for above circuit breaker applications. Comparison and evaluation based on specifications and experimental results are introduced.