A Novel Single-Phase Nonisolated Dual-Input Microinverter With Active Power Decoupling

Aiming at the challenges faced by single-phase nonisolated microinverters (MIs) such as leakage current and power fluctuation, a nonisolated common-ground MI with active power decoupling capability is proposed in this article. In this topology, the photovoltaic (PV) module and the grid have a common terminal, thereby eliminating the common-mode leakage current. Power decoupling between dual-input sources and the grid is inherent, so electrolytic capacitors can be replaced with long-life, small-capacity film capacitors. The proposed MI requires only four switches and can handle the power of two PV modules in a modular manner. A 400-W experimental prototype has been built in the laboratory to verify the performance of the proposed MI and the feasibility of the proposed scheme.