3300-V SiC MOSFET Short-Circuit Reliability and Protection

This paper investigates the short-circuit (SC) capability of the 3.3-kV 5-A silicon carbide (SiC) metal–oxide–semiconductor field-effect transistor (MOSFET) from GeneSiC (Generation-1, engineering sample). The SC withstand time (SCWT) of the tested 3.3-kV device could not reach the benchmark of 10-μs at a 2.2-kV bus voltage and 18-V gate voltage. A three-step ultra-fast SC protection method is introduced and validated. It can detect a SC fault and reduce the saturation current within 80 ns, then softly turn off the device within 2 μs. Using this protection method, the SC energy can be reduced by around 32%. Additionally, a noise immunity test showed this protection would not be falsely triggered at the device’s rated current. Medium-voltage (MV) SiC MOSFET based power conversion systems could utilize this method to enhance their SC capabilities without incurring efficiency losses.