A Very High- Power Density Multilevel Inverter Using Silicon Carbide (SiC) Commercial-Off- The-Shelf (COTS) Parts

The objective of this work was to design a motor drive for electric aircraft propulsion using commercial-off-the-shelf components with a power density above 50 kW/ kg. A three-level flying capacitor topology was selected and co-simulated with the motor design in detail. The mechanical design was carried out including the thermal management system. This design involved custom-built aluminum laminated buswork. A single-phase prototype was constructed with SiC MOSFET modules and tested up to the designed dc voltage of 1.8kV. It was necessary to increase the gate resistance to improve the electromagnetic compatibility. The thermal management system design involved a loop of the cryo-cooled motor and thus the MOSFET junction temperature could be regulated to room temperature at rated operation. The power density of the motor drive was calculated to be 60 kW/ kg.