Design, Implementation, and Validation of Electro-Thermal Simulation for SiC MOSFETs in Power Electronic Systems

Silicon carbide (SiC) mosfets are getting popular in high-frequency power electronic (PE) applications. More and more concerns for system efficiency and reliability are growing due to the increasing switching losses and thermal stress. In this article, an electro-thermal simulation method for SiC mosfets in modern PE systems is proposed. In the device simulation, a behavioral transient model of SiC mosfets is developed and used for generating a multidimensional power loss table in a wide range of operating conditions. The effects of parasitic elements, temperature-dependent parameters, and reverse recovery effect of the diode are taken into account. Furthermore, the power loss look-up table is integrated into the PE system simulation with an additional Cauer-based dynamic thermal model considering heatsink impact. In this way, the instantaneous power losses and junction temperature can be obtained, respectively, with fast simulation speed, reasonable accuracy, and improved simulation convergence. The proposed approach is implemented in PSCAD/EMTDC and further validated by the experimental results of a double pulse test setup and a power factor correction system.