Control Scheme for Single-Phase Grid-Connected Inverter Based on Modified Odd-Harmonic Repetitive Control

A control method is proposed in this article for grid-connected inverters, and the main feature of the method is that it contains a modified odd-harmonic repetition controller (MORC), and the other parts of the controller also contain proportional-integral controller (PI) and capacitor current feedforward. The MORC is originated from the repetitive controller and has the characteristics of greater gain and wider bandwidth at odd-harmonic frequencies. Due to this feature, the proposed control scheme has high control accuracy, fast transient response and stronger adaptability to grid frequency fluctuations. The control parameters are designed based on the stability analysis of the system under the proposed control method. Simulation results verify the effectiveness of the control method.