Design of Ultracompact Gate Driver Integrated With Current Sensor and Commutation Path for a 211-kW Three-Level SiC Aircraft Propulsion Inverter

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 multi-level 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 paper proposes an ultra-compact multi-functional 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, ultra-fast short-circuit protection, and ac load current sampling. The gate driver’s electric-field can be controlled by PCB-based shielding and shaping to eliminate the PD at high altitudes, thereby improving power density and reducing insulation risk. The paper presents the design methodology of the multi-functional ultra-compact 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.