Joint optimization of bow-type fast charger locations and battery capacity for electric buses

The transition from fossil fuel-powered buses to battery electric buses (BEBs) is occurring gradually; however, BEBs encounter challenges such as limited driving range and extended charging durations, which highlight the need for the development of optimized charging solutions. The bow-type fast charger, characterized by its high charging power and capability for unmanned operation, presents a viable option. These chargers can be strategically installed at terminals or intermediate stops, enabling BEBs to leverage their dwell time for charging purposes. This study formulates a mixed integer programming model aimed at jointly optimizing the locations of bow-type fast chargers, the battery capacity of the buses, and the bus schedule for a specific bus line. The primary objective is to minimize the combined costs associated with the construction of chargers and the acquisition of vehicles. Empirical data from an operational BEB line in Meihekou City, China, is employed to validate the model. Additionally, the study examines the sensitivity of three critical parameters and the impact of random disturbance factors. The optimization outcomes in scenarios that do not account for charging time limitations at intermediate stops are also evaluated. Findings indicate that the service time utilization rate at intermediate stops equipped with charging bows exceeds 90%. This suggests that BEBs can effectively utilize their dwell time for charging, thereby facilitating the synchronization of BEB charging with the bus schedule.