Dv/dt Sensing-Based Short-Circuit Protection for Medium-Voltage SiC mosfets

This letter presents a novel short-circuit protection (SCP) for medium-voltage (MV) SiC mosfet s, that utilizes the turn- on dv/dt of SiC mosfet within a predetermined interval to monitor SC faults. Unlike conventional methods that detect the fault current/voltage magnitude, proposed turn- on dv/dt detection and protection timing sequence enable a very fast fault response time as well as enhance the noise immunity to fast switching of MV SiC mosfet s. Furthermore, the proposed dv/dt sensing based SCP can be integrated with DESAT circuit to provide over-current protection under the fault-under-load condition. The proposed integrated implementation can respond to SC faults without the blanking-time limitation and eliminates the need for the extra high-voltage sensing capacitor to lower cost. Experimental results on 3.3-kV SiC mosfet s are provided to validate the effectiveness of proposed SCP method.