A Single-Source-Based Non-Isolated Micro-Inverter with Active Power Decoupling

In order to mitigate the negative effect of multi-frequency ripple power, a non-isolated micro-inverter with active power decoupling has been proposed in recent years, which shows some potential advantages, in terms of low cost, fewer switches, high efficiency, and a brief system control strategy. However, it has two independent PV panel input dc sources, which may be asymmetrical in realistic PV systems, resulting in a decrease in the power generation capacity of the whole system. To address this problem, an improved non-isolated micro-inverter topology with active power decoupling is proposed in this paper. Similar to the conventional micro-inverter, it can effectively suppress the common-mode leakage current. Different from the conventional micro-inverter topology, it uses a single PV panel input dc source and achieves positive and negative half-line cycle equivalent dc sources through two split-bus capacitors. The simulation has validated the effectiveness of the proposed non-isolated micro-inverter.