Assessment of PSpice model for commercial SiC MOSFET power modules

In this paper, a circuit level simulation model for SiC MOSFET power modules has been assessed. The static and dynamic characteristics of a 1.2 kV 800 A SiC MOSFET power module has been measured, simulated and verified in the PSpice circuit simulation platform. The SiC MOSFET power module is evaluated in two case studies, first where the power module is treated as a single device (simulated with one sub-module) and secondly where the performance of the power module is simulated as multiple MOSFET chips in parallel (multiple sub-modules). Here, the bond-wires between the chips are also included as inductive elements. The simulated static characteristics of the SiC MOSFET power module are well aligned with the measured data. In the first case, the simulation model in PSpice shows accurate dynamic performance overall, with exceptions from high-frequency oscillations that arises during turn-on and turn-off. The second case study shows that the oscillations can be captured by introducing multiple MOSFET chips in parallel and where the bond-wires in between are represented by inductors. A slight increase of high-frequency oscillations is noticed but on the cost of reduced simulation robustness (e.g. convergence issues) due to a more complex simulation circuit. Finally, it is concluded that the simulation model performance is overall accurate, both for static and dynamic performance. Further, the model is capable to estimate on-state loss and switching loss in a satisfactory manner and is utilized to evaluate and optimize power electronic converter cell parameters, for instance stray inductance, gate resistance and temperature, and their impact on converter energy loss.