Abstract

The aviation industry is increasingly interested in high-efficiency and high-density electric propulsion systems enabled by high-power silicon carbide (SiC) modules. However, designing a high-power SiC-based multilevel inverter for aircraft faces several challenges, including high loop inductance, bulky current sensors, high-bandwidth sampling of device current, partial discharge (PD) at high altitudes, and shorter short-circuit withstanding time of SiC MOSFETs. To address these challenges, this article proposes an ultracompact multifunctional gate driver that integrates the driving circuit, Rogowski coil current sensor (RCCS), and commutation path for a 211-kW SiC-based three-level (3-L) propulsion inverter. The optimized commutation path and RCCS provide multiple functions, including suppressing overshoot voltage, ultrafast short-circuit protection, and ac load current sampling. The gate driver's electric field can be controlled by printed circuit board (PCB)-based shielding and shaping to eliminate the PD at high altitudes, thus improving power density and reducing insulation risk. This article presents the design methodology of the multifunctional ultracompact gate driver and the board-level to system-level common-mode (CM) noise modeling and suppression. The performance of the gate driver is verified on a 211-kW 3-L altitude-ready SiC propulsion inverter system, achieving a power density of 19.5 kW/kg and 7.1 kW/L.