Charging Control of A Vanadium Redox Flow Battery Integrated With Solar PV Plant

Renewable energy sources such as solar and wind power are increasingly being used as alternative energy sources globally to create a low carbon society. For the next generation grid with significant share of distributed energy sources, energy storage technologies are essential. Vanadium redox flow batteries (VRFBs) have many advantages over other energy storage technologies. In the context of the solar plant operation, these batteries can significantly improve ancillary services of frequency regulation and voltage control to support the grid. This paper develops a VRFB model to apply a stand-alone solar system for residential applications. Both maximum power point tracking and voltage control modes are applied to the solar system. A bidirectional DC-DC converter is designed for management of the 5 kWh battery system. The vanadium redox flow battery (VRFB) is used to control the unpredictability of energy supply, serving both as an energy source and a consumer. Introduction of the VRFB and corresponding energy management system enables smoothening and energy shift of solar output, enhances the system reliability with real-time monitoring, operation, regulation, stable and effective operation, and overall system performance optimization. Described system is validated by simulations in MATLAB/Simulink.