Electrical-Thermal-Mechanical Considerations for the Design of a Compact Two-Level Current Source Inverter using GaN Devices

This paper presents an application of GaN devices for the development of a low temperature current source inverter (CSI) meant for higher efficiency and power density applications targeting future electric aircrafts. A detailed investigation about influence of layout parasitics onto device over voltages and output voltage waveform is carried out. The paper optimizes the commutation loop by having a 'Y' shaped layout for CSI with the lowest ever re-ported inductance of 3.51 nH. The paper also discusses the CSI inverter design from thermal and mechanical aspects and their impact on electrical performance. The design concept is validated with three phase experiments using GaN devices, by developing two different configurations of CSI, where design of commutation loop inductance has also been verified by double pulse test (DPT) results. The paper presents detailed analysis and trade-offs between commutation loop optimization, and its impact on gate driver placement, and mechanical assembly.