A Modeling Method of SiC-MOSFET Short-circuit Failure Based on COMSOL Multiphysics and Simulink Co-simulation

As a typical device of wide-band semiconductor, SiC-MOSFETs have the advantages of high temperature and high voltage tolerance, fast switching speed, and low conduction loss, which have great potential in high power density and high-power applications. Thanks to the advantages, the short-circuits withstand time is much shorter than Si-MOSFET (2-7μs), so the establishment of the SiC-MOSFET short-circuit thermoelectric coupling model is important to improve the device application reliability and short-circuit protection circuit design. However, it is difficult to accurately characterize the junction temperature variation of different types of power devices, especially for the power devices of different processes technology. Since the short-circuit junction temperature of the device changes rapidly, considering the unbalanced thermal conductivity of different heterogeneous structures inside the chip, the accuracy of the short-circuit junction temperature model becomes the key to analyzing the short-circuit failure of power devices. Therefore, this paper proposes a simulation method based on the combination of the Simulink circuit model and the COMSOL Multiphysics device model, which can couple the actual power circuit and power device through the function interface. It realizes the joint simulation of independent SiC-MOSFET device models and different simulation circuits so that the circuit system is approached to the actual power circuit.