Novel Hybrid Circuit Breaker Topology Using a Twin Contact Mechanical Switch

DC smart grids have become very popular over the last decade. Furthermore, protection of DC grids has always been a challenge that must be addressed. DC fault has a different behavior from AC fault in which zero crossing current helps current interruption in circuit breakers. Moreover, DC fault current increases to much higher levels and in a faster pace as there is a small amount of reactance in DC systems comparing to AC systems. Hybrid Circuit Breakers (HCBs) are attractive for slow dynamic traditional load based microgrids due to their excellent conduction loss. However, the effect of their added reactance to the grid, which is a necessity to limit the fault current, severely decreases the grid response time to the pulse loads disqualifies them for most of the high demand modern micro grids. The all new Twin Contact HCB (TCHCB) offers a significantly smaller Current Limiting Reactance (CLR) making it a great alternative to Solid State CBs (SSCBs) with considerably high conduction loss and prerequisite of a cooling system.