An Isolated Single-Stage Single-Phase Micro-Inverter Topology with Integrated Magnetic Components

This paper introduces a new single-phase, single-stage, grid connected and isolated micro-inverter (MI) topology for Solar Photovoltaic (PV) applications. The proposed topology is a flyback (FB) based voltage source inverter (VSI), which alternates the role of an integrated magnetic component (IMC) between high frequency (HF) FB transformer and grid inductor, depending on the operating cycle. The inclusion of these IMCs facilitates delivery of continuous sinusoidal grid current and provides galvanic isolation. Additionally, by integrating these functions into one device, the total component count is not only reduced, but the topology is kept simple, since the proposed IMCs are basic two winding structures that are easy to design and analyze. Practical operation of the proposed MI is verified by simulation and experiment using a laboratory prototype. The results confirm the operation of the MI and show that the proposed topology guarantees sinusoidal current output and conforms to other theoretical predictions.