Model-Based Cost-Benefit Analysis on Si/SiC Hybrid Switches for Traction Inverters

Abstract:
This study presents a model-based cost-benefit analysis of a silicon/silicon carbide (Si/SiC) hybrid switch (HyS) traction inverter for electric vehicles. The HyS consists of a SiC MOSFET and a Si IGBT connected in parallel. We simulate how a chip area ratio between the two affects the cost-benefit balance of a traction inverter, assuming that the cost comes from the chips used and a battery, where the battery capacity is set to meet a target mileage. The simulations provide the optimal chip configuration mapping for a given battery capacity and SiC MOSFET cost. The results demonstrate that the HyS is optimal for inverters with a battery capacity of 10–30 kWh, typical of plug-in vehicles, compared with configurations employing only Si or only SiC devices.