Research and Application of a Combined Energy Management Strategy of EV Charging Station with PV and BES

Abstract

Electric vehicle (EV) charging station with photovoltaic (PV) and battery energy storage (BES) is an innovative attempt in the construction of EV charging station. Three subsystems-PV, BES and charging facilities form a microgrid within the station, making intelligent interaction between the station with the public power grid possible. In this paper, a combination of several energy management strategies is designed, which are put into use at different stages. At the initial stage of operation, a basic rule-based control strategy including seven modes is designed. When sufficient historical operation data are acquired to forecast the EV charging load and PV output of the next day, a day-ahead optimization strategy based on mixed integer linear programming (MILP) model is designed to maximize the profit of the charging station, considering the impact of time-of-use (TOU) electricity price, PV generation subsidy, PV feed-in tariff and charging business revenue. With the above day-ahead plan, a real-time adjustment strategy based on MILP model is also designed to ensure real-time power balance with an objective of minimum adjustment cost. This paper takes Shanghai Xinqiao charging station as an example to test the effectiveness of the strategies in optimizing the station-level operation.