System Impact of Silicon Carbide Power Electronics on Hybrid Electric Vehicle Applications

The emergence of silicon carbide- (SiC-) based power semiconductor switches with their superior features compared with silicon (Si) based switches has resulted in substantial improvements in the performance of power electronics converter systems. These systems with SiC power devices are more compact, lighter, and more efficient, so they are ideal for high-voltage power electronics applications including hybrid electric vehicle (HEV) power converters.

In this dissertation, first, a power supply converter and a traction drive converter of an HEV are selected and then, the impact of SiC-based power devices on these converters is investigated. Reductions in heatsink size and device losses with the increase in the efficiency are analyzed using an averaging model of a three-phase PWM inverter in the traction drive. In addition to these, the reductions in the filter and transformer size for the power supply are also included. For more accurate results, experimental data and/or device physics are taken into consideration to model power diodes and MOSFETs.

Finally, suggestions of parameter modification to design better performing application specific power devices are made after a parametric study of the devices.