Optimal Sizing of Photovoltaic and Battery Energy Storage of Electric Vehicle Charging Station Based on Two-part Electricity Pricing

This paper focuses on optimal sizing of photovoltaic (PV) and battery energy storage system (BESS) of special-use charging station for electric taxi cabs. Aiming to minimize annual equivalent cost of the charging station under two-part electricity pricing mechanism, an optimal sizing algorithm of PV and BESS is established considering the randomness of PV output and the power constraint of the grid, as well as whether charging station participates in demand response (DR). The cooperative operation strategies of charging facilities, PV and BESS under typical scenarios are proposed. Considering the factors that affect the optimal results, this paper provides sensitivity analysis in a charging station. Finally, the proposed optimal sizing algorithm is verified in the charging station equipped with 24 EV charging piles, and the economic analysis of the optimal sizing scheme is carried out. Based on economical analysis of optimal sizing results, it is found out that the equivalent cost of EV charging station is lower when participating in demand response. The results show that the annual equivalent total cost of the charging station is significantly reduced under the new optimal sizing scheme.