25 kW 1200 V unidirectional DC solid-state circuit breaker design with SiC MOSFET desaturation detection

This paper proposes a silicon carbide (SiC) metal oxide semiconductor field effect transistor (MOSFET) based a solid-state circuit breaker (SSCB) with a desaturation detection method. Since the SiC MOSFET has a higher switching speed than general semiconductors, the SSCB can achieve faster and higher blocking performance. However, protecting SiC MOSFETs from short circuit conditions is not easy, because fault blocking occurs with a large overshoot in the drain-source voltage. Thus, this paper proposes design methods for a snubber circuit and a desaturation detecting method to protect SiC MOSFETs. This design method is based on SSCB blocking operation equations, and a simulation is conducted to verify the equations. In addition, the stray components of the printed circuit board (PCB) are simulated to make an exact comparison with experiments. An SSCB is built based on the equation and tested under fault conditions. The experimental results demonstrate that the proposed SSCB blocks short circuit current of less than 0.9 mu s. Finally, a thermal test is conducted at the rated load to validate the heat control performance.