FPGA-Based Forced Air-Cooled SiC High-Power-Density Inverter for Electrical Aircraft Applications

High power density and high-efficiency inverter is required for electric aircraft application due to the restriction of volume and weight. In this paper, a prototype of a 150 kVA inverter using wide bandgap SiC has been developed for electric vertical takeoff and landing (eVTOL) aircraft application. The thermal properties of the SiC MOSFET have been analyzed and a corresponding air-cooled heatsink has been designed and tested. The gate driver circuit is carefully designed to minimize the stray inductance and the ringing of voltage is mitigated. The inverter system has been tested with 700V input and 70A phase current at a 20 kHz switching frequency. For the control of the 3-phase inverter, this design proposed an FPGA-based control board for high-resolution high-speed modulation index adjustment. A system power density of 47 kW/L is estimated to be achieved with a dimension of 110*155*185 mm.