A 3 kW GaN HEMT Based Three-Phase Converter Achieving a Switching Frequency of 300 kHz and an Efficiency of 97.06%

Abstract

With wider electrification in various sectors, there is a great demand for high-power, high-efficiency and high-power-density converters. Compared with conventional Si devices, the ultra-fast-switching speed of gallium nitride (GaN) high-electron-mobility-transistors (HEMTs) can enable power electronics converters to achieve very high switching frequencies, which can help to reduce the current ripple and hence significantly reduce the filtering components such as filter inductors and capacitors. The high-frequency GaN HEMT converter can also be used for very high-speed, high-fundamental-frequency motor drives and other applications. This article has evaluated the performance of GaN HEMTs through double pulse test (DPT) as well as continuous test in a DC/AC three-phase converter, which provides benchmarking results demonstrating the capabilities of GaN devices. A detailed power loss and efficiency model considering the parasitic capacitive effect has been developed for GaN converters and an experimental prototype has also been built to evaluate the converter performance. Through experimental evaluation, 3 kW output power, 300 kHz switching frequency and 97.06% efficiency have been achieved. Further, 1.5 kW output power, 600 kHz switching frequency with an efficiency of 94.42% have also been achieved.

Keywords

• DC/AC converter
• efficiency
• GaN HEMT
• switching frequency