Design of LVDC Bidirectional Hybrid Circuit Breaker

One of the most challenging hindrances to the spread use of the DC grids is their protection devices. Due to the absence of zero crossing, when a fault occurs, arc extinction becomes an issue for the traditional mechanical circuit breakers. Thanks to the recent advances in solid-state circuit breakers, this problem is solved because of the absence of mechanical contacts in their topology. However, these breakers cause not negligible conduction losses. This paper illustrates a new low-voltage bidirectional hybrid circuit breaker able to interrupt short-circuit current in few milliseconds. It provides a low-loss path for the current during the normal conduction and a fast current interruption with a limited arc level in case of fault occurrence. The working principle of the device is explained, and its functionality is proven through simulation results.