A Ground Clamped Solid-State Circuit Breaker for DC Distribution Systems

In solid-state circuit breakers, back electromotive forces need to be synthesized across the breakers to absorb the electromagnetic energy stored in the system inductors and ultimately clear the fault current. For the conventional solid-state circuit breaker, the back electromotive force is synthesized due to the difference between its switch surge voltage and its source voltage, which makes the voltage rating of its switching devices excessively overdesigned in the systems having significant inductances and sensitive loads. To overcome this dilemma, a new Ground Clamped Solid-State Circuit Breaker for DC distribution system has been proposed here. In comparison with its counterpart of conventional solid-state circuit breaker applied to the same scenario, the proposed breaker clears fault current in a significantly shorter break time by employing switches rated at lower voltage as well as surge protectors at lower energy volume and therefore the breaker can have lower material costs and longer life span. The installation of the proposed breaker into DC distribution systems with designs of integrated load converter, resonant capacitor and bi-directional configuration has also been proposed to demonstrate its practical values. The plausibility and superiority of the proposed breaker have been validated by the simulation and experimental results in the paper.