Robust repetitive control of three-phase inverter system using high order internal model

Abstract

© 2016 TCCT.In order to improve the static and dynamic responses of three-phase grid-connected inverter systems, this paper proposes a composite control consisting of a PI control and a repetitive control. This method can be used to reject the periodic harmonic signals, and thus improve the converter output performance. A high-order repetitive controller is adopted to further improve the robustness against the uncertainties in the period of signals. The main contribution of this paper is to analyze and compare the robustness of first-order repetitive control and high-order repetitive control against modeling error and frequency variation. Finally, comparative simulations based on a circuit level inverter model are conducted to show that high-order repetitive control can reduce the net current harmonics of the three-phase inverter system when there are period uncertainties, and thus obtain better steady-state and dynamic responses.