Research On Reliability Analysis And Status Assessment Of High Speed Railway Overhead Contact Systems

High-speed railway catenary is not only an important running equipment of electrified railway but also the direct power source of High-speed railway.However,the catenary equipment is in the open environment for a long time without standby,which is the weak link in the train operating system.If there is a problem,it will affect the safe operation of the train,and when it is serious,it will cause great casualties and economic losses.Therefore,it is very important to analyze the reliability of over contact system(OCS)and grasp the change of operation state of OCS in time to ensure the safe and reliable operation of OCS.This paper mainly completes the following contents for the reliability analysis and operation state evaluation of High-speed Catenary.Firstly,based on the theory of reliability analysis,the binary decision diagram(BDD)is introduced into the reliability analysis of catenary system.According to the structure of OCS,the construction process of fault tree model of OCS and the transformation steps from fault tree model to BDD model are explained.On this basis,common cause failure(CCF)theory is applied to the reliability analysis of OCS,and the reliability analysis of OCS based on BDD considering common cause failure is completed by implicit substitution method.Secondly,based on the state evaluation theory,the evidence theory and AHP are applied to the operation state evaluation of OCS.According to the current collection characteristics of high-speed railway pantograph and catenary,a three-level index system for operation state evaluation of catenary is established.Moreover,by obtaining the operation state detection data of OCS and normalizing it according to the deterioration function,the whiteness weight function value of the corresponding three-level index is obtained,and then the weight value of the two-level index is obtained by using the analytic hierarchy process.Then,the index information fusion is completed by using the evidence theory and the index weight,and the operation state evaluation result of OCS is obtained.Finally,according to the results of reliability analysis and operation state evaluation,the maintenance suggestions of OCS are put forward.Through the reliability analysis and operation state evaluation of high-speed railway OCS,it is shown that the reliability analysis method combining BDD method and CCF not only considers the characteristics of the analysis object,but also simplifies the calculation process,and the calculation results are more consistent with the actual situation;the operation state evaluation method using evidence theory and analytic hierarchy process(AHP)can fully represent the operation state of OCS Fuzziness and randomness can also effectively put forward suggestions for catenary maintenance according to the comprehensive evaluation results.