Queue Based Dynamic Charging Resource Allocation and Coordination for Heterogeneous Traffic in an Electrical Vehicle Charging Station

Abstract

ABSTRACT Electric vehicle (EV) fast-charging stations (CSs) with innovative operation management strategies can help to meet the growing EV charging needs. Despite the short charging time associated with the fast charging of EVs, massive deployment of plugged-in EVs for fast charging triggers network surges in the distributed network. Nevertheless, these challenges can be effectively addressed with appropriate EV admission control, charging resource allocation, and coordinated charging strategies. This work proposes an innovative EV-CS operation mechanism that maximizes the CS profit by allowing fast charging EVs to access the CS opportunistically without stressing the distributed network. Furthermore, a queue is employed in the dynamic resource allocation process to favor more fast charging requests through buffering non-critical slow charging EVs, as fast charging users would otherwise be blocked or forcibly terminated. Performance of the proposed priority-based charging coordination is analyzed in terms of the optimum utilization of demand limit, charging completion rate, and charging station utilization. Therefore, it keeps the average charging station utilization above 90% at higher arrival rates of EVs while the distribution transformer is being loaded only up to 50% of its rated capacity. Moreover, the blocking and forced termination probabilities of fast charging users are used to evaluate the service quality of EV charging. The presented dynamic resource allocation and charging coordination strategies for heterogeneous EV traffic maximize the CS profit while assuring quality service to EV users without stressing the distributed network.