High Step-Up DC-AC Inverter Suitable for AC Module Applications

In this paper, a novel grid-connected high step-up inverter is proposed. The topology is composed of two stages. The first stage is a single-switch high step-up dc-dc converter with bipolar outputs, and the second stage is a conventional half-bridge dc-ac grid-connected inverter. Negative grounding of the photovoltaic (PV) module has resulted in elimination of unwanted ground leakage currents in the PV system. Simple structure, employing few semiconductor switches, simple control, and high efficiency are the features of the proposed topology. Theoretical analysis and principal operation of the circuit are discussed. An experimental prototype is implemented to verify the performance of the proposed inverter. The experimental results confirm the aforementioned features and the theoretical analysis of the converter operation.