Dynamic Switching of SiC Power MOSFETs Based on Analytical Subcircuit Model

Compared to silicon counterparts, silicon carbide (SiC) power mosfets have lower on-state resistance and faster switching speed, which in turn makes them better candidates for high-voltage power switching applications. This creates a growing need to develop device models for such SiC power devices. The models that are currently being used are mostly physics-based models, which require all the physical parameters of the device and are not so suitable for real time hardware in loop simulations. In this article, we show a subcircuit model based on the analytical study using nonlinear curve fitting method for modeling of dynamic switching behavior. Using a 1.2 kV, 17 A mosfet as a testbed, this subcircuit model is validated by implementing the model into Synopsys Saber in comparison with the measured dc characteristics, the Saber mosfet Tool model, and the manufacturer's model. The switching behavior of the device at 800 V/17 A and 800 V/5.5 A based on the subcircuit model were also compared and validated with experimental measurements, the Saber mosfet model, and manufacturer's model. Excellent agreements were achieved on both dc characteristics and switching behaviors. On the LTspice platform, the computation time of the analytical subcircuit model is 4.5 times faster than the manufacturer's model. This subcircuit model is adoptable and suitable for real time hardware in loop simulations and power converter designs.