Thermal Performance Investigation of a High-Current & High-Power Density GaN-Based Motor Drive for All Electric Aircraft Applications

Integration of electric machine, drive system, and cooling system in a single structure was proposed as a solution to meet the high power density and efficiency requirements in aviation applications. From the drive perspective, both the efficiency and power density are highly dependent on the switching device selection. Thus, semiconductors with small footprint and low on-state resistance are desirable. Integrating the power converter with the electric machine limits the available space, thus the PCB should be designed accordingly. Considering the space constraint in addition to the efficiency and power density requirements for such an application, the thermal performance of the designed converter is pivotal. In this paper, the thermal performance of a high-current & high-power density GaN-based motor drive is evaluated. At first, using the PLECS software, the performance of the power converter was simulated at rated load conditions. Using PLECS’s thermal library, the characteristics of the cooling system are modeled. Based on the simulation results, the cooling system configurations that can satisfy the constraints of the drive system are determined. Finally, the performance of the drive module was evaluated through DC and AC testing.