Improvement of an electro-thermal model of SiC MPS diodes

This study presents improvements introduced in a behavioural electro-thermal model of silicon carbide merged PIN-Schottky (SiC MPS) diodes, aimed at a better representation of device characteristics for a more accurate prediction of power dissipation. In the electrical domain, the junction capacitance model has been thoroughly validated with a new parameter extraction procedure, yielding realistic values of the turn-off charge as well as current and voltage waveforms for various operating conditions, which is crucial for dynamic loss evaluation. The validity of the thermal sub-model has been extended by reflecting the temperature dependence of thermal conductivity. As a result, temperature evolution on both the long and short time scales is properly computed, providing correct on-state voltage drop and on-state power loss results. Device behaviour with a heat sink attached is also correctly simulated.