基于Wiener退化过程的动车组部件状态-机会维修模型分析与研究

Condition-based Opportunity Maintenance Model Analysis and Research for EMU Components Based on Wiener Degradation Process

针对动车组多部件存在运行维修成本高、欠维修或过维修的现象以及故障影响范围大等问题,提出一种基于Wiener退化过程的部件状态-机会维修优化模型。该模型利用Wiener过程描述部件在运行过程中的劣化程度,通过基于指数分布的随机几何过程反映不完全维修后部件的劣化损伤,同时利用定期检测获取部件的实际劣化值。从随机过程和拓扑的角度,分析不同类型维修策略之间的区别与联系。结合单部件状态维修优化策略,求得各部件的最优状态阈值和维修检测周期。引入机会阈值与状态阈值的比值,结合部件退化过程与状态阈值、机会阈值之间的关系,推导部件状态、机会维修次数期望值的数学表达式,建立状态-机会维修策略模型,采用蒙特卡洛算法进行模拟,确定各部件的最佳机会阈值,达到优化维修费用率的目标。以某型号动车组牵引供电系统为例,通过仿真验证,表明采取状态-机会维修模型,可以有效减少停机次数,降低维修费用率。

In response to the problems such as high maintenance cost,less maintenance or excessive maintenance,and large range of fault effects for electric multiple unit(EMU)components,the paper proposed a condition-based opportunity maintenance(CBOM)model based on Wiener degradation process.In the model,by using the Wiener process to describe the degradation degree of the components during operation,a random geometric process based on exponential distribution was used to reflect the degradation damage of the components after incomplete maintenance,while regular inspections were conducted to obtain the actual degradation value of the components.From the point of view of stochastic process and topology,this paper analyzed the differences and relations between different types of maintenance strategies.Combined with the optimization strategy of condition-based maintenance(CBM)of a single component,the optimal condition threshold and maintenance detection period of each component were obtained.By introducing the ratio of the opportunity threshold to the condition threshold,and considering the relationship between the degradation process,the condition threshold and the opportunity threshold,the mathematical expressions of the expected values of the component condition and the opportunity maintenance frequency were derived before the establishment of the strategy model of condition-based opportunity maintenance.The strategy model was simulated by Monte Carlo method in order to determine the optimal opportunity threshold for each component and achieve the goal of optimizing the maintenance cost rate.Based on the case study of the traction power supply system of an EMU train,the simulation results show that the condition-based opportunity maintenance model can effectively reduce the downtime and the maintenance cost.