A dynamic RC-network equivalent thermal model is constructed to analyze the behavior of a three-phase pulse-widthmodulated (PWM) voltage source inverter using silicon carbide MOSFETs (SiC MOSFET) as the switching devices. A Spice model containing parasitic parameters is introduced to evaluate the switching energy loss that significantly affects the switching device thermal behavior. A prototype based on SiC MOSFET is developed and tested to validate the proposed model. Furthermore, the model is extended to perform a generalized trade-off study consisting of different topologies and switching devices. It is shown from the trade-off study that a SiC MOSFET based PWM inverter is the optimal choice for the specific system discussed in this paper.