GaN HEMT based single-phase inverter control with consideration of nonlinear load

Abstract

GaN HEMT devices provide significant advantages over silicon MOSFET with lower gate charge, faster switching speed and smaller reverse recovery charge. It is hopeful to use this device to get high efficiency and high power density compatibly. A GaN HEMT device based full-bridge single-phase inverter with switching frequency 260kHz is proposed to evaluate the advantages of GaN power transistors in this paper. Synchronous reference frame proportional-integral (SRFPI) based outer voltage control and inner inductor current control in stationary reference frame are used in inverter control system, voltage feedforward decoupling is introduced to simplify control system design and degrade negative effect of voltage dynamics to inductor current. Load current feedforward and repetitive control are used to prevent voltage distortion caused by nonlinear load. Simulation and experiments validate the proposed control method.