A 2 kW Gallium Nitride based switched capacitor three-port inverter

Abstract

This paper presents a single phase, multilevel, three-port, switched capacitor inverter based on Gallium Nitride (GaN) devices from Transphorm. The features of this inverter include one 200 V dc port, and two ac ports, which are two-level 120 V (1X inverter) and three-level 240 V (2X inverter), respectively. This circuit harness the superior characteristics of GaN devices, especially their faster switching speed and lower on resistance, to reduce the passive components size, increase overall power density, and achieve multiport operation. In this paper, complete circuit description, operation principles and device evaluation are provided. Also, to verify proposed functions, a 2 kW prototype has been built and the preliminary testing results have shown a 98.5% peak efficiency with two ac outputs.