In this paper, we propose a closed queueing network model for performance analysis of electric vehicle sharing systems with a certain number of chargers in each neighborhood. Depending on the demand distribution, we devise algorithms to compute the optimal fleet size and number of chargers required to maximize profit while maintaining a certain quality of service. We show that the profit is concave with respect to the fleet size and the number of chargers at each charging point. If more chargers are installed within the city, we show that it can not only reduce the fleet size, but it also improves the availability of vehicles at all the points within a city. We further show through simulation that two slow chargers may outperform one fast charger when the variance of charging time becomes relatively large in comparison to the mean charging time.

中文翻译：

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电动汽车共享系统中的车队规模和充电器分配

在本文中，我们提出了一种封闭排队网络模型，用于在每个社区具有一定数量的充电器的电动汽车共享系统的性能分析。根据需求分布，我们设计算法来计算在保持一定服务质量的同时最大化利润所需的最佳车队规模和充电器数量。我们表明，相对于车队规模和每个充电点的充电器数量，利润是凹的。如果在城市内安装更多的充电器，我们表明它不仅可以减少车队规模，而且还可以提高城市内所有点的车辆可用性。我们通过模拟进一步表明，当充电时间的变化与平均充电时间相比变得相对较大时，两个慢速充电器可能会胜过一个快速充电器。