Joint Optimization of Electric Bus Infrastructure Planning, Fleet Composition, and Charging Schedule Considering Multi-Gun Charging and Compatibility

Public transportation electrification stands as a crucial strategy in combating climate change and reducing carbon emissions. However, due to short driving ranges and limited charging resources, it becomes imperative to collectively optimize the battery electric bus (BEB) fleet, charging schedules, and charging infrastructure to enhance system efficiency. This study proposes an electric bus system optimization method considering vehicles to charging guns compatibility and multi-gun fast charging, in which BEBs can be charged by multiple charging guns simultaneously. Firstly, we establish a mixed integer programming model to minimize the total costs of the BEB transit system, including the purchase costs of charging guns, fleet composition costs, and electricity costs. Then, to accelerate the solving speed, a dual extended column generation algorithm (DX-CG) is designed to solve the model. Finally, the proposed model and algorithm are validated by the bus network in Nanjing, China. The results show that the proposed algorithm outperforms traditional column generation (CG) algorithms and CPLEX in both solution time and quality. Compared with the baseline solution, the total costs are reduced by 6.79%, and the utilization rate of charging facilities increases by 30.30%, verifying the effectiveness of the proposed method. The findings in this study provide practical guidance on BEB charging scheduling and promote the sustainable development of bus transit systems.