Three-phase three-level GaN-ANPC inverter with a 1 MHz switching frequency

Abstract

Gallium nitride high-electron mobility transistors (GaN HEMTs) have superior switching performance, when compared to similarly rated silicon switches. High switching frequency operation is enabled by low switching transition times and switching losses. High switching frequency can be beneficial in an electric drive, as the output filter size can be decreased, and furthermore a sinusoidal inverter output current produces low motor losses and torque ripple. Nevertheless, the performance of GaN HEMTs in high switching frequency three-phase inverters remains unraveled. In this paper, the design and implementation of a three-level ANPC inverter prototype employing GaN HEMTs and a 1 MHz switching frequency is presented. The measured output voltage and current waveforms are sinusoidal, however, some distortions are visible due to modulator design. Furthermore, the prototype exhibits a peak efficiency of 96.56 % at 2.1 kW output power with an LR load.