Design and Implementation of a Single-Phase Buck-Boost Inverter

In order to simplify the configuration of photovoltaic (PV) grid-connection system, this paper proposes to adopt a buck-boost dc-dc converter, and then develops a single-phase inverter via the connection with an H-bridge unfolding circuit with line-com mutated. Depending on the conditions of dc inputvoltage and ac output-voltage, the proposed circuit can work functionally as either a step-down or step-up inverter. It is suitable for the applications with wide voltage-variation range. Since only one switch is operated with high-frequency, the switching loss can be significantly reduced to improve the efficiency. Finally, a laboratory prototype with 110 V-rms / 60 Hz output voltage is then simulated and implemented accordingly to verify the feasibility of the proposed inverter.