The High Speed Railway Catenary System Performance Degradation Assessment Based On Detected Parameters

The high-speed and efficiency property of the high-speed railway proposed new requirements to the traction power supply system's maintenance,and catenary system,as one of the major parts of the traction power system,shoulders more responsibilities for the security of the high-speed railways' power supply system.Catenary equipment is set up along the line and has no back-up,its complex structure,poor working conditions and various fault types make it more prone to accident than other devices.Therefore,if the performance can be detected and assessed,it would be possible to make the system maintenance plan well targeted and improve the reliability of the system.The performance degradation assessment on catenary system aims at analyzing the degradation process which involves different stages from the initial degradation to the final failure,and identifying the current operating states of the system.However,the complexity and particularity of the catenary system make the work more tough to carry out:firstly,for the catenary system,there is a lack of prior information on the various degradation patterns of its fault types.Secondly,the catenary equipment is vulnerable to the external environmental disturbance,moreover,the maintenance work is involved during its operation,thus,it is usually difficult to make the accumulation of data under the whole process of abnormal state.Aiming at the above two problems,the performance degradation assessment based on detected parameter data is studied systematically in this paper,and the main contents are as follows:First,the measured data of parameters,which is obtained through the investigation on the Wuhan-Guangzhou high-speed railway(Qingyuan-Guangzhou north down line),are introduced in this paper,and then extracted the characteristics parameters describing the performance state of the catenary system,which are used as the data resources for the follow-up study.Then,the paper focuses on the method applied to performance degradation assessment of the Continuous Hidden Markov Model(CHMM).Some improvements of CHMM has been discussed,including the initialization of the model,the optimization of the algorithm,etc.The whole framework of performance degradation assessment and degradation state identification based on CHMM are proposed under the situation of incomplete state data.A quantitative index describing the degradation degree of the catenary system is presented,and the self-adapting alarm algorithm is discussed according to the features of catenary system.Based on the measured data of parameters,the degradation performance of catenary is discussed separately under the condition of single parameter and multi parameter.Then the degradation performance assessment of the contact network,the identification of the current state,the performance index and the output of the multi-level alarm are realized,The result validates the effectiveness of the model and the feasibility of the whole scheme,which can provide a reasonable reference for the maintenance and health assessment of the catenary system.