Energy Management Method of PV-battery System Based on Doubly Grounded Topology

To address the problem of common mode leakage current effect in PV-battery systems based on transformer-less PV inverters, a doubly grounded topology is used to fundamentally eliminate this defect, which contains a photovoltaic unit, two energy storage units, and an inverter. On this basis, the power relationship of each unit of the system is analyzed. An energy management control strategy is proposed to achieve the power balance of the system and the state of charge (SOC) equalization of two batteries to maximize the energy utilization. Finally, the feasibility of the proposed energy management control strategy is verified by simulation results.¹