| With the development of high-speed and heavy haul railways,the current transmitted between the catenary and the pantograph has increased,and the temperature of the contact material during operation has increased significantly.The increase of temperature will cause complex physical and chemical changes in the surface of the contact material,which will affect the current-receiving quality of the pantograph and catenary system and the service life of the contact material.At present,there is no research on the influence of the temperature of the contact pair on the electrical characteristics of the pantograph,and the influence of the temperature of the contact pair on the friction and wear performance is still controversial.The main reason for the controversy of the influence of temperature on the friction and wear performance is that the existing research mostly changes the temperature by changing the test parameters such as contact pressure and current,so it cannot be judged whether the change of the friction and wear performance is caused by the change of the test parameters or the temperature change.Therefore,it is necessary to carry out research on the influence of the contact pair temperature on the electrical characteristics and friction and wear characteristics of the pantograph and catenary system,and to improve the understanding of the influence of the contact pair temperature on the sliding electrical contact characteristics of the pantograph and catenary.The research results can provide important guidance for the development and selection of pantograph strip materials and theoretical basis.Based on the self-made pantograph strip temperature control system and the high-speed ring-block sliding electrical contact tester,the pantograph-catenary sliding electrical contact test at different temperatures was carried out,and the changes in the total arc discharge energy and the average single arc discharge energy at different temperatures were analyzed.Combined with the arc ablation morphology of the surface of the strip,the reasons for the difference in arc discharge between the contact pairs at different temperatures are analyzed;the variation of pantograph dynamic and average contact resistance under different temperatures was studied,and the influence mechanism of temperature on the electrical contact performance of pantograph pair was found.Set the temperature as the independent variable to carry out the friction and wear test.The changes in the friction coefficient of the pantograph-catenary system and the wear of the strip at different temperatures are clarified;the chemical composition of the surface of the strip under different conditions is analyzed,and the difference in the surface abrasion morphology of the pantograph strip at different temperatures is investigated;the influence mechanism of temperature on the friction and wear characteristics of pantograph pairs was proved.Finally,given the pantograph strip wears affected by many factors,it is difficult to accurately predict the strip wear.Carry out the sliding electrical contact test under different speeds,contact pressure,test time,temperature and current,and explore the influence of different factors on the wear of the strip.Based on the partial least-square method,the regression analysis of the test data was carried out,and the prediction model of strip wear was established by comprehensively considering the influences of velocity,contact pressure,time,temperature,current,average single arc discharge energy,contact resistance and friction coefficient on the strip wear,the model can provide a reference for the prediction of the wear of the train pantograph strip and the replacement of the strip,and reduce the operation and maintenance cost. |
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