Energy Management Based on the Photovoltaic HPCS With an Energy Storage Device

This paper proposes the new energy management method based on the photovoltaic (PV) hybrid power conditioning system of 4 kW with an energy storage device (ESD). The use of the ESD such as a lithium-ion battery improves the energy efficiency of the overall system depending on time and weather conditions. In addition, the proposed system provides the new function for energy management in real time without weather forecasting while it considers the power generations from the PV system, residential load variations, and electricity price. In other words, the proposed energy management system (EMS) can reduce the electricity price by charging the energy of nighttime electric power. In addition, it can suppress the grid voltage variations caused by the large amount of PV generations during daytime with respect to relatively less load demand. The performances of the proposed EMS system based on the 4-kW PV HPCS with a lithium-ion battery are evaluated by time-domain simulation. Thereafter, the experimental prototype is implemented in hardware to verify the usefulness of the proposed system.