Solid-state breaker protection in MVDC systems

The development of medium-voltage DC power distribution for future Naval ships brings questions about the protection methods to be used in various places within the architecture. This paper starts with overlaying the current-time curve of a solid-state DC breaker with a traditional DC breaker. Using both methods can address slowly encroaching faults and rapidly occurring faults. A medium-voltage DC system demonstrator is described which includes solid-state breaker protection. The system is tested in the laboratory where it is demonstrated that a hard fault can be isolated from a controlled rectifier by the solid-state breaker within the ultra-fast time period (sub-millisecond). With this system, faults of various time scales (slow, fast, and ultra-fast) can be addressed using traditional breakers, power electronic controls, and solid-state breakers.