A High-frequency Compact Zero-Voltage-Transition GaN-based Single-phase Inverter

Abstract

This paper presents a high-efficiency soft-switching GaN-based single-phase inverter composed of a full-bridge DC-AC inverter and an auxiliary circuit. The auxiliary circuit incorporates two active switches and an inductor coupled with the filter inductor. The auxiliary circuit does not add any components in the main power path, and no isolated gate driver is needed. Besides, using a coupled-inductor in the auxiliary circuit reduces the voltage stress on the switches and enables the utilization of GaN switches. Moreover, a variable-timing method controls the auxiliary circuit and reduces the conduction losses in the auxiliary switches. As a result, the efficiency and power density are improved. The proposed inverter is analyzed, and experimental results of a 200kHz, 500W prototype converter are reported.