多车型纯电动公交车使用下的混合车队替换优化

针对不同能源公交车辆的运营特性差异，考虑城市公交电动化率限制和不同能源车辆间的替换率，以降低公交车队运营管理成本为优化目标，研究多车型纯电动公交车可供选择使用下的混合车队替换决策问题，以确定最佳车队替换计划。考虑规划期为10年，以青岛市公交系统为实例进行数值分析。结果表明：车型选择对车队替换计划和运营成本有显著影响，与单一纯电动公交车型比较，多车型的使用能够极大地降低运营成本；燃油公交车和纯电动公交车组成的混合车队，比燃油和电能混合驱动的公交车，在运营管理中更具经济性；在任意公交电动化率目标下，小型纯电动公交车投入量应明显高于大型纯电动公交车投入量；当公交电动化率小于一定阀值时，不推荐投入大型纯电动公交车使用。本文研究成果将为城市公交车队运营管理决策提供依据。

Optimizing Mixed Transit Fleet Replacement with Multi-type Battery Electric Buses

Due to the different operational performances of buses powered by different types of energy, this study investigates a mixed transit fleet replacement problem using multi- type battery electric buses to obtain an optimal replacement plan under a specific fleet electrification target. The aim of this study is to minimize fleet operation costs and management costs. Besides, we consider associated diesel- electric replacement rates in the proposed model. A numerical experiment is performed using the Qingdao public transport system within a 10- year planning period. The results show that the vehicle type significantly impacts the fleet replacement plan and the total operation and management costs. Compared to the use of single electric bus type, multi- type fleet greatly reduces the total costs. Interestingly, a combination of diesel buses and electric buses is superior to hybrid buses powered by diesel and electricity. Given any fleet electrification targets, the number of small electric buses purchased is more than the number of large electric buses. Large electric buses are not purchased when the transit fleet electrification target is less than a threshold. The research results can provide a guidance for transit agencies to plan their fleet replacement in an economic and efficient manner