An Improved Methodology for Switching Losses Estimation in SiC MOSFETs

Abstract

This work presents an improved analytical model concerning the prediction of switching losses in power MOSFETs by considering the influence of parasitic elements in the high-frequency operation of devices. By using the transistor voltage and current waveforms, it is possible to predict switching losses under hard-switching conditions adopting only parameters that can be obtained from the device datasheet. The method employs the nonlinearities associated with the junction capacitances, which are incorporated into the model through curve fitting. Besides, the sensitivity analysis is used to identify which parameters have a major influence on the estimated losses. The methodology is described in details and verified by means of experimental results concerning a SiC MOSFET, which is tested under various current and voltage conditions.