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.