Table of parameters of the genetic algorithm.

Harmonious High-Power AC Electric Locomotive, as the main type of locomotive for freight transport in China, the safety of its operation and maintenance issues have been the focus of great attention by the operation department. How to reduce the high maintenance cost and shorten the time-consuming long maintenance is a pressing issue for the operation management. In this paper, for the C4 repair operation of the harmonious electric locomotive, using the preventive maintenance method, we constructed a multi-component maintenance plan optimization model with the aim of maximizing the availability, and solved it by using a heuristic genetic algorithm. On this basis, component-specific maintenance schedules were developed based on reliability thresholds. The results of the study showed that the preventive maintenance approach resulted in a 51.04% reduction in total cost and a 7.89% increase in availability over the same operating cycle compared to the traditional fixed repair schedule maintenance program. Under the premise of ensuring locomotive operational safety, it effectively saves costs, reduces maintenance downtime and achieves the objective of improving the quality of C4 repairs.和谐型大功率交流电力机车（Harmonious High-Power AC Electric Locomotive）作为我国铁路货运的主流机车类型，其运行与运维安全始终是运营部门高度关注的核心议题。如何降低高昂的运维成本、缩短冗长的检修耗时，是运营管理工作中亟待解决的现实难题。本文针对和谐型电力机车的C4修程，采用预防性检修方法，构建了以可用性最大化为目标的多组件检修计划优化模型，并通过启发式遗传算法对模型进行求解。在此基础上，基于可靠性阈值制定了分组件的检修计划。研究结果表明，相较于传统固定修程的检修方案，在相同运营周期内，预防性检修方案可使总成本降低51.04%，可用性提升7.89%。在保障机车运行安全的前提下，该方案有效节约了运维成本、缩减了检修停机时长，达成了提升C4修程检修质量的目标。