Study Of Factors Influencing Current Collecting Characteristics Of High-speed Railway Catenary

With the continuous improvement of railway operation speed,mechanical disconnection between contact wire and pantograph is inevitable,and there are even increasing signs.Off line operation will cause air ionization and arc between pantograph and catenary,which may damage pantograph and catenary while affecting current collection.The current collection quality and speed improvement of high-speed EMU trains are being hindered by the off-line phenomenon between pantograph and catenary,making it essential to investigate the off-line factors and features of pantograph and catenary in high-speed lines.Therefore,it is particularly important to study the off-line influencing factors and characteristics of pantograph and catenary in high-speed lines.Based on the research results of various countries on the current collection quality and domestic standards,this thesis summarizes a more comprehensive evaluation standard of the current collection quality,selects several catenary design parameters that have a greater impact on the current collection quality,and studies the impact of different catenary structure design parameters on the current collection quality.In this thesis,the most widely used simple catenary suspension catenary in China is selected.Based on this,a three-element reduced mass model of pantograph is established.The variable stiffness model of catenary under various structural parameters is obtained through the elastic calculation model of catenary.Then by establishing the dynamic balance equation,the static lifting amount of pantograph head under different driving conditions and the contact force of pantograph-catenary are solved,The pantograph-catenary contact force is selected as the excitation load during simulation.In this thesis,the sag of the catenary in the catenary is solved by the single string method to obtain the initial shape of the catenary,and then the finite element model is established by using the ANSYS Workbench software to study the transient dynamic analysis of the pantograph-catenary coupling of the catenary with different structural parameters and the change of the current collection quality evaluation standard parameters when the pantograph slides over the catenary.According to the analysis in this thesis,when the tension of the contact line is properly increased,the stiffness of the contact line can be increased,the elastic non-uniformity of the contact line can be reduced,and the dynamic lifting amount of the pantograph can be effectively controlled,so as to obtain higher current collection quality.It is beneficial to properly increase the tension of the messenger wire,but the tension of the messenger wire does not have a key impact on the current collection.With the increase of catenary span,the contact condition between pantograph and catenary deteriorates,the fluctuation range of contact force increases,and the vibration of catenary becomes more intense.With the increase of the span,the overall stiffness of the catenary in the span decreases,and the elastic non-uniformity coefficient has a trend of increasing with the increase of the span.Therefore,the span cannot be designed too large.Under the condition that other catenary parameters remain unchanged,the elastic non-uniformity coefficient of the catenary gradually decreases with the decrease of the dropper spacing,that is,the increase of the number of droppers.This suggests that we can improve the elastic uniformity of the catenary by appropriately reducing the number of droppers in a span,thus improving the current collection.