High-Power-Density GaN-Based Inverters for Drone Motor Drive Applications

Abstract

The demand for high-efficiency and high-powerdensity propulsion systems in unmanned aerial vehicles (UAVs) has driven the adoption of wide-bandgap semiconductor devices in electrical drives. Gallium Nitride (GaN) FETs enable higher switching frequencies, reduced passive component size, and improved thermal performance compared to conventional silicon MOSFETs. This paper presents an experimental and simulation-based investigation of GaN-based three-phase inverters for drone propulsion systems operating from a 48 V DC bus. Two hardware configurations based on EPC2361 GaN FETs are evaluated at switching frequencies from 40 kHz to 100 kHz. Thermal behaviour, motor temperature, and inverter losses are experimentally characterized. Furthermore, LTSpice simulations compare different GaN device configurations in terms of conduction loss, switching loss, PCB area, and cost. The results show a switching frequency evaluation for an optimal trade-off between inverter thermal stress and motor temperature reduction, over the power range for the motor propulsion considered, while enabling DC-link capacitor downsizing and improved power density for the inverter system.