Bidirectional Single Stage Grid-Interactive Converter for Renewable energy applications

Abstract

In this concept PV-based stand-alone scheme for application in rural areas is proposed. Photovoltaic (PV) has become one of the most promising candidates among the available RESs. However, the availability of PV power is intermittent in nature, and hence, PV-based stand-alone systems need an energy storage element which is generally realized by utilizing a battery bank. Reformations in electricity sector along with various renewable energy promotion policies have increased the importance of small grid connected photovoltaic (PV) systems utilizing bidirectional single-stage grid-connected inverter (BSG inverter) for the battery energy storage system. This paper proposes BSG-inverter is composed of multiple bidirectional buck-boost type dc-dc converters (BBCs) and a dc-ac inverter for grid connected (PV) system. The output current of the inverter can be adjusted according to the voltage of the photovoltaic (PV) array. Advantages of the proposed BSG-inverter include: single-stage power conversion, low battery and dc-bus voltages, pulsating charging/discharging currents, and individual power control for each battery module.