Predicting the junction temperature of SiC MOSFETs during continuous operation is essential for evaluating ampacity and reliability requirements. These predictions are often performed in circuit-simulation software such as PLECS. However, developing these models requires accurate measurements and implementation of various loss mechanisms. While conduction losses and hard-switching losses are generally well understood and included in models, EOSS losses caused by the charging and discharging of the COSS capacitance in SiC MOSFETs are often omitted. This can cause substantial inaccuracies in simulation, particularly for soft-switching applications with zero current switching (ZCS) schemes, where EOSS is a dominant loss factor. This presentation discusses calculation methods of EOSS and its implementation in PLECS simulation models. Attendees will gain insight into the importance of EOSS in soft-switching applications and how to include them for ZCS applications.
