Electro-Thermal Simulation for Predicting the Temperature of SiC Dies in the Power Module of a High Frequency Operating Power Converter

摘要

In the proposed study, an accurate electro-thermal simulation was performed to predict the temperature of SiC metal-oxide-semiconductor field-effect transistor (MOSFET) chips in a power module used for constructing a buck converter. This method is capable of reproducing an uncommon characteristic of SiC MOSFETs, which is the negative gate-voltage of the SiC MOSFETs increases the forward operation voltage of its body diode. This yields a precise estimate of power dissipation in the buck converter and stationary-state temperature of the SiC MOSFET. The buck converter selected for the experiment comprised a 1200 V, 40 A power module operating at switching frequencies varying from 50 to 350 kHz. The deviation ratio between the measured and simulated temperature results was less than 6.0%, even for the worst-case scenarios.