Optimal Operation of Virtual Charging Systems for Plug-In Electric Vehicles

This article proposes a novel concept, denoted as virtual charging system (VCS), for electric vehicles (EVs). In a conventional charging system (CCS) with a competitive environment, the competition between charging stations can utilize game theory as a price competition game model. On contrary, charging stations with different ownerships under the VCS umbrella will cooperate to act as one charging station for EV drivers in order to increase customer satisfaction and obtain more profits collectively and individually. The proposed VCS consists of three parts - participating charging stations, EVs contracting with the VCS, and finally the VCS operator. The operator is responsible for optimally routing the EVs to a suitable charging station within the VCS. A new formulation for implementing this novel concept is presented to allow interaction between various VCSs to maximize the profit gained by each VCS as well as minimize the transit charging time and cost for each customer as a measure representing customer satisfaction. Different case studies are introduced to evaluate the significance of the VCS concept. The performance of the VCS is compared to CCS, and the results show that VCS provides superior customer satisfaction and higher profit.