Capacity Optimization of Energy Storage for Photovoltaic Station Considering SOC Control

Power fluctuations of photovoltaic stations can be attenuated by battery energy storage system (BESS). Considering the expensive energy storage cost, BESS is still an expensive option for smooth the PV power fluctuations. Thus, capacity optimization of energy storage can reconcile the relationship between energy storage cost and the smoothing effect. Based on this, a novel algorithm is proposed to optimize the capacity of energy storage system. The adaptive control of state-of-charge (SOC) is proposed to avoid over-charge or discharge of energy storage system which will improve life span of energy storage devices. Afterwards, an objective function is presented to minimize the sum value of invest cost, operation cost and punishment cost. The calculation results verify the validity of the proposed algorithm.