Long term profit maximization strategy for charging scheduling of electric vehicle charging station

As electric vehicles (EVs) penetration level is increasing, charging infrastructure should expand. This study concentrates on the economic aspects of EV charging stations (EVCSs). When CS capacity is not enough to simultaneously charge all EVs, the EVs will wait in queues to get service. This study presents a model for EVCS and a profit-based algorithm for charging scheduling (ChSc) of EVs from viewpoint of EVCS owner. The objective function is to maximise long-term profit of EVCS owner and to minimise delay time of EVs. The charging prices of queues are different from each other, which are determined by the EVCS owner, considering energy price. The time needed to charge an EV from the minimum state of charge to fully charge is considered as a time interval. It is shown that maximising profit at each interval, named as short-term profit maximisation (STPM), does not necessarily maximise long-term profit of the EVCS owner. Then, another ChSc strategy, referred to as long-term profit maximisation (LTPM), is proposed. Simulation results confirm that with LTPM, the owner of EVCS obtains more profit in long term. Also, in comparison to STPM, the incurred average delays of EVs in queues are much less.