Design of a Mobile Charging Service for Electric Vehicles in an Urban Environment

This paper presents a novel approach to providing a service for electric-vehicle (EV) battery charge replenishment. This is an alternate system in which the charge replenishment is provided by mobile chargers (MCs). These chargers could have two possible configurations: a mobile plug-in charger (MP) or a mobile battery-swapping station (MS). A queuing-based analytical approach is used to determine the appropriate range of design parameters for such a mobile charging system. An analytical analysis is first developed for an idealized system with a nearest-job-next (NJN) service strategy explored for such a system. In a NJN service strategy, the MC services the next spatially closest EV when it is finished with its current request. An urban environment approximated by Singapore is then analyzed through simulation. Charging requests are simulated through a trip generation model based on Singapore. In such a realistic environment, an updated practical NJN service strategy is proposed. For an MP system in an urban environment such as Singapore, there exists an optimal battery capacity with a threshold battery charge rate. Similarly, the battery swap capacity of an MS system does not need to be large for the system to perform.