Single-stage low cost grid connected inverter in photovoltaic energy applications

Due to the rising fuel costs and growing worldwide demand for electricity, renewable energy sources become a necessity rather than a luxury. This paper presents an original control strategy for a buck-boost based converter used as a low cost inverter in a photovoltaic (PV) system. The main objective of the inverter is to harvest maximum power from the PV module and to inject it into the grid. The design of the converter is detailed and, together with the control method, a macro-model for the inverter is proposed. The macro-model is developed in order to have shorter simulation times and test various maximum power point tracking (MPPT) algorithms. Simulations and experimental results validate the proposed PV system.