Nonlinear Capacitance Model of SiC MOSFET Considering Envelope of Switching Trajectory

The nonlinear capacitance model is important to predict the dynamic characteristics of SiC mosfet s. Different from the conventional modeling method extracting the parameters from the full data, this article proposes a modeling method based on the envelope of the switching trajectory, which greatly reduces the complexity of the model and avoids divergence during the simulation. The proposed modeling method clarifies the value range of gate–source voltage v _gs and drain–source voltage v _ds in each interterminal capacitance operation period, and only necessary data will be taken into consideration, whereas the unnecessary data out of switching trajectory will be discarded. In order to verify the correctness and accuracy of the proposed model, the SiC mosfet C2M0080120D (1200 V/36 A) with the nonlinear capacitances is modeled in the Pspice environment and compared with the measured results of the double-pulse experiment. The proposed model is also simulated in a full-bridge inverter. The results show that the proposed model has enough accuracy and efficiency in dynamic behavior prediction of SiC mosfet s, which would be potential for the more complex system-level simulation.