Optimal charging control for electric vehicles in stand-alone PV charging stations

Optimal charging and scheduling control for electric vehicles (EVs) in stand-alone PV charging stations based on time compensation is analyzed in this paper. In stand-alone PV charging stations, PV array experiences large variations of its output power under intermittent and uncertain weather conditions, a large number of EVs fueled by stand-alone PV charging stations has a great stochastic and flexibility charging behavior, that makes it difficult for stand-alone PV charging stations under safe and economic operation. Under the constraints of stand-alone PV charging stations capacity and EVs charging needs, a stochastic optimization based dispatching model, capable of accommodating uncertain outputs of EVs and solar generation, is proposed to maximize the overall economic benefits of stand-alone PV charging stations. Then, the policy iteration algorithm is utilized to solve the objective function to obtain an optimal charging policy, which maximizes the overall economic benefits of stand-alone PV charging stations in the long run. Finally, the analysis results show that the synthetic efficiency for solar energy utilization, the service availability for EVs and the economic benefits of the stand-alone PV charging stations can be improved by reasonable allocating charging policies, and the practicality and effectiveness of the model are further verified.