Day-Ahead Scheduling for Electric Vehicles in Charging Stations Intergrated with Renewable Energy Source

Abstract

Electric vehicles are increasingly growing worldwide as a result of their environmental benefits. However, uncoordinated charging of electric vehicles has several adverse effects on the charging stations and the electric network. So, coordination of electric vehicles charging is essential. These vehicles can operate in two modes, grid-to-vehicle mode when they charge from the electric network and vehicle-to-grid mode when discharging their energy. Therefore, electric vehicles can help charging stations in minimizing their operating costs by permitting the stations use them as distributed storage. The economic and environmental advantages of electric vehicles can be significantly increased if the charging station is integrated with renewable energy sources. The charging and discharging schedules for electric vehicles in a charging station provided by a photovoltaic system are proposed in this paper. The scheduling of the day ahead is optimized to minimize the operating cost of the charging station using the improved whale optimization algorithm which simulates the humpback whales' hunting behavior and hybridized with the mutation part of the differential evolution algorithm to improve the optimal solution. Case studies have been simulated to compare the coordinated charging/discharging strategy with uncoordinated and coordinated charging strategies. The results show that the proposed strategy provides better results compared to other strategies in terms of the daily charging station's operating cost.