Robust predictive current control of a grid-connected inverter with harmonics compensation

Abstract

Usually, predictive current controllers have been known as the dead beat controller with a high bandwidth. Most predictive current control methods have shown high performances in RL based inverter model. The grid-connected inverter need to interface with LCL filter, however it is very sensitive in terms of resonance problem. In this paper, a robust predictive current control scheme is proposed for the grid-connected inverter with LCL filter. Three stages deadbeat control is designed to decouple the discrete inverter model. In order to minimize the resonant behavior during the grid connection, the predictive active damping method is added with the phase and gain compensations. In addition, a DQ-reference frame filer based harmonics prediction provides enhanced current regulation under the grid distortion. Finally, the proposed control method is able to obtain fast controller's responses as well as robust harmonic compensation through predictive approach. Simulation results show the proposed control method under the grid distortion is able to achieve fast and robust responses.