Study On Reliability Analysis And Maintenance Of The Electrified Railway Catenary

The overhead catenary system (OCS) is set up along the railway, which supplies power to the train through pantograph. OCS has a very serious working environment, which will lead to the catenary’s failure easily. With the development of electrification railway, to ensure the sustained stable supply, the demand of the reliability of the catenary system is ever-increasing. However, the research of the reliability of OCS started late relatively. Study of the reliability can not only improve the stability of power supply, but also optimize the repair costs and repair plan. Therefore, it is necessary to study the reliability of the OCS.In this paper, the life of each part of OCS is regarded as different distributions in order to make the reliability more practical. Thus the reliability of the whole system is examined.In the paper, the main factors that caused the failure of catenary system is analyzed, which is the bad dynamic performance between catenary and pantograph, including not perfect repair plan, poor working environment, and low wire material etc. Different analysis methods of system reliability are studied and the advantages and disadvantages of each method are compared in order to complete the OCS reliability comprehensive analysis. The FTA (fault tree analysis) is selected as the method to analyze the reliability of the OCS.Then the fault tree of catenary is established according to the previous research experience. And the quantitative analysis is carried on. With the assumption that the life of each part of the catenary system is regarded as different distributions, the distribution parameters are estimated because of the shortage of the measured data. So the repair costs and repair time of the OCS are deduced.Then after determining the different fault distribution, aviation parameter estimation method is introduced in detail, such as the probability of drawing method, least square method, maximum likelihood estimation method, etc. As long as getting the detailed data of failure, the unknown parameters of the distribution can be directly estimated. It is more accurate than the estimated parameter values.Finally, in order to set up scientific maintenance plans, the maintenance cost and consuming time have to be studied. The failure data of three years in Changsha period is used to calculate the catenary reliability distribution parameters. Programming on the optimization calculation of the maintenance cost. The preventive maintenance strategy is discussed based on reliability.The different distribution functions are adopt to describe the reliability of the every parts of the catenary, which offers a new way for accurate analysis of the catenary system reliability, the research conclusion can provide beneficial reference for optimization of the catenary system maintenance plan.