Single‐Phase Single‐Stage Isolated DC–AC Inverter With Double‐Frequency Current Ripple Compensation Port

ABSTRACT The single‐phase single‐stage isolated photovoltaic (PV) microinverter typically requires bulky electrolytic capacitors to buffer double‐frequency ripple power, limiting lifespan and power density. This paper proposes a novel single‐stage isolated DC–AC topology with an integrated compensation port for active power decoupling. The topology‐level power decoupling mechanism between the AC and compensation ports is realized through resonant network optimization, eliminating complex software decoupling matrices. A multi‐loop closed‐loop control strategy is designed based on a derived small‐signal model to achieve PV‐side ripple suppression, grid current control, and compensation‐port voltage regulation. A 400‐W prototype is built for experimental verification. The proposed inverter reduces the required DC‐side capacitance from a conventional 9752 μF to only 300 μF, and limits the double‐frequency current ripple within 10% over the 10%–100% rated load range. All active switches achieve reliable zero‐voltage switching (ZVS) within the same load range, with a peak efficiency of 94.9%.