Maximum Power Flow Management for Stand-alone PV Based Battery Charging System

Photovoltaic (PV) system can be one of the renewable energy source used to charge the electric batteries. However, a significant amount of PV power is wasted if the maximum available power does not fully utilized by the batteries charging process appropriately. In this study, a maximum power flow management technique is proposed for stand-alone PV based battery charging system. A set of Li-ion battery cells of different capacity and state of charge (SOC) is considered for charging. A decentralize three stages constant current/constant voltage (CC/CV) charging strategy and DC-DC buck converter with maximum power point tracking (MPPT) is utilized to charge these battery cells by using the PV system. A maximum power flow management algorithm based on forecasted PV generated power is proposed to select the appropriate number of battery cells for charging at a particular time that able to receive maximum power from the PV system. In addition, the different preventive measure including overheating and overcharging is also considered in the charging process. The simulated system achieved 88.3% utilization of PV generated power.