Integrated Optimal Control System for a Household Photovoltaic-Battery Energy Storage System

Due to substantial uncertainty and volatility, photovoltaic (PV) power generation is often paired with a battery energy storage (BES) system to generate electricity, especially in a low-voltage distribution system. This paper proposes an integrated optimal control system for a household PV-BES system. The PV-BES system can feed the local load, sell the excess power to the grid in grid-connected conditions, and feed the local load to avoid losses during power outages. The integrated optimal control system can automatically or manually select the economic operation mode or forced charging mode in grid-connected conditions and stably supply the local load considering the battery’s state of charge (SOC) in the islanded cases. To verify the performance of the proposed control system, the validation is implemented under various scenarios, considering electricity on-peak and off-peak hours, the SOC of the battery, the difference between the load and output of the PV-BES system, and grid-connected or islanded situations. The hardware experiment results show that the proposed integrated control system can control the PV-BES system well and maximize the benefit for households, regardless of grid-connected and islanded conditions.