Modeling and Validation of Medium Voltage SiC Power Modules

Ongoing advancements in medium-voltage (MV) SiC technology are setting the stage for the development of power dense and efficient MV converters. However, computationally-efficient models to support application development with MV SiC MOSFETs are not yet widely available. This paper presents an efficient and robust behavioral model for MV SiC MOSFETs that is implemented in LTspice. In this paper, the parameters of this model are tuned to the static characteristics of a 6.5 kV SiC MOSFET. Reasonable agreement is obtained for the forward, transfer, third quadrant, and CV characteristics of this device. This single-die model is used to implement a full-scale LTspice model for a 6.5 kV SiC MOSFET half-bridge module (XHV-7) currently under development by Cree|Wolfspeed. The developed model is empirically validated using Double-Pulse Test (DPT) experiments at a range of operating conditions up to 5 kV and 800 A. The XHV-7 LTspice model predictions are shown to be in good agreement with the empirical DPT waveforms at multiple operating conditions. Finally, a comparison is performed with the measured switching losses, in which the XHV-7 module is found to demonstrate approximately 12⨯ lower switching losses than similarly rated IGBT modules.