Structure and analysis of the Z-source MVDC breaker

The medium-voltage dc (MVDC) architecture shows potential for future ship power systems. Components of the MVDC system are fairly well established; with the exception of circuit breakers. The main problem with the breakers in dc systems is the absence of a zero crossing in the current needed to extinguish an interrupting arc. Options for breakers in MVDC systems include over-sizing traditional ac breakers, hybrid mechanical/semiconductor breakers, and solid-state breakers. The recently introduced z-source breaker is most similar to the solid-state breaker, but has the additional feature of automatically responding to faults quickly and without the need for fault detection. Furthermore, the z-source breaker isolates the generation source from the fault current. This paper presents detailed analysis of the z-source breaker as well as variations on the topological structure. The various breaker options are validated through detailed simulation.