High Current Solid-State Circuit Breaker for safe, high efficiency DC systems in marine applications

We present the design and experimental validation of the parallel connection of Reverse Blocking IGCTs (RB-IGCT) for high current solid-state circuit breakers for DC shipboard power systems up to a nominal voltage of 1 kV and a nominal current of 5 kA. DC power distribution enables efficient and flexible distribution of power between primary sources and loads for both all-electric commercial and combatant ships. However, the power requirements and the performance of the DC distribution system requires very fast fault protection in order to provide protection selectivity, high survivability, and reconfigurability after a fault event. The high current solid-state circuit DC breaker presented here can react and limit fault current up to a thousand times faster than electromechanical and hybrid solutions. The circuit topology is based on the parallel connection of low conduction loss RB-IGCTs which delivers efficiency as high as 99.9%. The developed solid-state DC circuit breaker can detect a fault current within 10 µs or less, limit the fault current within 20 µs or less, even in distributions systems with very high di/dt and perspective fault currents of 100 kA or more.