High-Frequency Split-Phase Air-Cooled SiC Inverter for Vehicular Power Generators

This paper presents a novel high-frequency split-phase SiC inverter suitable for vehicular power generators. Electrification of vehicles such as recreational vehicles (RV's), fire trucks, and media/telecommunication vans requiring variable-speed generators and power electronics are discussed. Two inverters, designed using commercially available all-SiC MOSFET and Si IGBT power modules, are built and tested to compare their electrical and thermal performances. PSIM models of the SiC MOSFET and Si IGBT inverters are developed to estimate the power losses of the split-phase inverter topology. For a given low-cost air-cooling system designed using extruded aluminum heatsink with limited air flow of 300 CFM, the thermal performance of two inverters using an SiC MOSFET and an Si IGBT power module are evaluated to estimate their output power capabilities. For this predefined air-cooling system, the simulation, experimental, and thermal analyses show that SiC MOSFET inverter offers 40% more output power at 14 kW compared with 10 kW of Si IGBT inverter when switched at 20 kHz. Furthermore, for an 8 kW split-phase inverter design, losses in 40 kHz SiC module are evaluated to estimate the size and cost reduction of the output filter inductor to demonstrate the commercialization potential of wide bandgap (WBG) power electronics for mobile power generators in transportation.