The short-circuit robustness of Silicon Carbide (SiC) MOSFETs is crucial for the safety of traction inverters used in electric vehicles (EVs). This paper primarily addresses the challenges associated with accurately extracting the input capacitance CISS of SiC MOSFETs, particularly under high drain-source voltage VDS conditions with gate-source voltages VGS above the MOSFETs threshold voltage VGS,th, where traditional measurements based on LCR-meters or impedance analyzers limit the range of bias conditions to zero or low ID currents. We propose a novel methodology for CISS extraction that enhances the modeling of short-circuit behavior in SiC MOSFETs. By focusing on the depedency of CISS by VDS and VGS compared to solely on a single value, we improve the accuracy of models for short-circuit robustness estimation, thereby facilitating more reliable designs for traction inverters. The simulation results in comparison to measurements shown for 1200V SiC MOSFETs underscore the importance of well-defined and accurately modeled parameters in the development of robust power electronic systems.
