A new single phase transformerless photovoltaic inverter topology with coupled inductor

This paper presents a new single phase transformerless PV inverter topology using a coupled inductor to meet the requirements of high efficiency, small volume and low cost. The new topology provides a solution for an inverter with inherent step-up and step-down behaviour especially suitable for grid connected PV systems. The main advantages of this inverter are simple symmetrical control, flexible grounding configuration and high efficiency over a wide input voltage range. To prove these features, a theoretical analysis of the proposed circuit is performed first. Then design approaches and optimizations of the circuit components are explained. Finally a constructed and tested 2.5kW prototype will be presented and measured results of the proposed single phase transformerless PV inverter are shown.