Design and Experimental Validation of a High-Power-Density GaN-Based Inverter Module for Integrated Modular Motor Drives in All-Electric Aircraft Applications

The integrated modular motor drive (IMMD) concept is a promising solution for transportation electrification. IMMDs offer essential features such as high power density, efficiency, and reliability which are critical for electrified propulsion systems. While integration provides advantages in power density and efficiency, it also presents significant design challenges due to space constraints. In this study, a single inverter module of a 250 kW IMMD is designed and tested, which functions as an autonomous power converter. Each module contains a power converter, dc-link capacitor bank, and a local microcontroller, enabling independent control. The modules of the targeted IMMD are identical, allowing for easier replacement of failed units and reducing production complexity and cost. The designed inverter module underwent testing to evaluate both its switching characteristics and continuous operation. The manufactured inverter module obtained a gravimetric power density (specific power) of 43.96 kW/kg and an efficiency of 98.65%.