VOC-Based Active Power Decoupling for Single-Phase Photovoltaic Inverter

Active power decoupling control methods are effective in solving the problem of the second-order ripple power in single-phase inverter systems. Among them, the automatic power decoupling control method is widely used for its excellent power decoupling performance. However, when the inverter achieves power decoupling, the decoupling capacitor voltage generates a large second-order ripple to buffer the ripple power, which degrades the output AC current quality of the inverter. In addition, the phase-locked loop also affects the quality of the AC power, especially in the case of grid voltage distortion. To address these problems, in this paper, an active power decoupling control method based on virtual oscillator control is proposed. Simulation and experimental results show that the proposed method has the advantages of stronger robustness in mitigating fluctuations of capacitor voltage and good adaptability to distorted power grids.