An Ultrafast Short-Circuit Protection for High-Voltage SiC MOSFETs Based on Q desat -Transfer Detection With Robust dv/dt Noise Immunity

This paper proposes an ultrafast short-circuit protection (SCP) scheme for medium-voltage (MV) SiC MOSFETs by introducing aQdesat-transfer-based sensing mechanism, offering robust immunity to highdv/dtnoise. The proposed scheme indirectly detects the drain-source voltage drop amplitude by using theQdesattransferred during highdv/dtto determine whether the MOSFET is properly turned on. Integrating a gate detection unit and a desaturation detection unit, it fully leverages the advantages of both gate charge characterization-based detection and desaturation detection methods, achieving ultrafast response. The blanking time of the desaturation detection method is determined by theVdsfalling time and the reverse recovery time of the diode, which allows the RC time constant to be set very small. Moreover, utilizing the charge transferred by the displacement current during highdv/dt, the proposed method eliminates the dependence on transientdv/dtmeasurements and thus enhances the noise immunity. Experimental results confirm the excellent performance of the proposed method, which achieves total response times of 69-92 ns for hard switching faults (HSF) and 134 ns for faults under load (FUL) under different bus voltages. The scheme provides reliable protection even under extremedv/dtconditions of up to 46.8 V/ns, ensuring secure operation for high-cost MV SiC-based power converters.