RC assisted close-loop Active Gate Control (AGC) for Solid-state DC Circuit Breaker (SSCB)

Solid-State DC Circuit Breaker (SSCB) have been proposed for faster breaking response as compared to traditional electromechanical circuit breakers. It offers the potential for integration of functionality and reduction of footprint of the system. This is achieved by operating the devices in active region to limit the start-up current through capacitive loads. This paper proposes a RC assisted close-loop Active Gate Control (AGC) to soft-start capacitive loads. The proposed solution aims to achieve a more generalized solution which is independent of device type and characteristics while offering utilization of off-the-shelf gate drivers. The negative feedback based close-loop AGC offers the advantage of compensating device's non-linearities and dependencies. The proposed solution also gives the flexibility of either using RC circuit to soft turn-off under load and bypass it after start-up process for faster response under low impedance fault. This paper discusses the dynamics of the devices and close-loop design of the system. To validate the proposed solution, simulation and experimental results are given on a 900 V 15 kW prototype.