Impedance source converter for photovoltaic stand-alone system with vanadium redox flow battery storage

Photovoltaic stand-alone systems require an energy storage component to provide continuous energy to the load when the solar intensity is inadequate. A vanadium redox flow battery has many prominent attributes which make its integration with a photovoltaic stand-alone system highly attractive. This paper investigates a 3kW photovoltaic stand-alone system including solar panels, impedance source converter and vanadium redox flow battery. Impedance source converters are new type of DC-DC converters with buck and boost operating capability, offer greater range of DC output voltage, high reliability and reduce ripple currents. The equivalent circuit and the charging characteristics of the vanadium redox flow battery are provided. Impedance source converter acts as the power conditioning converter which receives the maximum power from the photovoltaic panel and maintains the constant voltage across the battery by controlling its duty cycle. The results are provided to study the charging behavior of the battery and to validate the advantages. (c) 2017 Elsevier Ltd. All rights reserved.