Analysis and Implementation of a High Power Interleaved Flyback Photovoltaic Microinverter With Valley Skip Conduction Mode for Low Cost and High Efficiency

ABSTRACT For photovoltaic microinverters, power generation cost and efficiency are critical considerations. To reduce cost, this article designs a high‐power flyback photovoltaic microinverter based on a novel connection architecture, while employing the valley skip conduction mode to enhance efficiency. First, a mathematical model of the reference current under valley skip operation is derived. Based on the derived model, this article further proposes using the grid‐connected current as the criterion for valley selection and implementing the valley skip function entirely through software. To evaluate the robustness of the system, a sensitivity analysis of parameter variations is conducted. Both analytical and experimental results demonstrate that the proposed method maintains soft‐switching capability under parameter deviations. Finally, a prototype featuring a four‐in‐one connection architecture with a rated output power of 1800 W was developed, and the effectiveness of the software implementation for the valley skip control strategy was validated.