Reliability Research Of Multi-state On The High-speed Railway Overhead Line Support Device

As the carrier of power supply system,the overhead line has important significance in ensuring the safety of the stable operation of electric locomotives.As one of the most important systems,the reliability of support device directly affects the reliability of overhead line.However,the overhead line is extremely complex and interconnected,its fault state is not single either.Therefore,the reliability analysis method of traditional two-state is not good enough to express its multi-state and uncertainty.In this paper,the analysis is based on the investigation,the fault report of the recent 6years and work log of the high-speed railway contact network support device.At the same time,databases of all railway system in China have been all analyzed.At last on the basis of the traditional two state system reliability analysis method,a multi-state reliability analysis method based on the Bayesian network is proposed and established,and the multi-state Bayesian network model of the support device has been set up.Meanwhile,the reliability of the support device has been researched.Firstly,the fault polymorphism and uncertainty in the reliability analysis of support device are analyzed and explained.The reliability analysis method of multi-state Bayesian network is proposed.Furtherly,its principle,basic content and reasoning algorithm are briefly introduced.Then,according to the reliability index calculation method of complex system and the database data,the reliability index of each part of supporting device is calculated.Secondly,according to the method of establishing Bayesian network through the fault tree,the Bayesian network model topology of the contact network support device is established by using the information of the evaluated and pruned fault tree with the period expectation.On the other hand,the bar probability table of the support device is obtained by the expert scoring method based on the analytic hierarchy process.The parts of the priori probability are obtained after the combination of the method of the reliability index and frequency statistics and calculation.Then the posterior probability of each component in two states of fault and serious fault is exactly obtained by using the algorithm of the cluster tree propagation algorithm in Bayesian network model.Finally,the weak links of supporting devices under different fault conditions were diagnosed.Furthermore,the probability importance and key importance degree of the components of the support device are calculated in different state states.At the same time,the reliability distribution of the components is carried out by the Bayesian network method,Meanwhile,combine the two importance degree to find the weaker but important parts.The types and factors of the failure of the weak link in supporting device are analyzed,and the corresponding maintenance strategies are provided,at last but not least some suggestions for improving the reliability are put forward.Finally,through Python3+PyQt4+Eric4,combined with Matlab and C language,the multi-state reliability research software platform for the high-speed railway overhead linesupport device has been developed and designed,which provides convenience for the multistate reliability analysis of the support device in the actual project.Finally,the software platform and BN model of Chengdu Railway Bureau were verified by the fault data of 2017 Railway Bureau,which proved its correctness and superiority.