Research On Insulation Joint Burning Loss Of Track Circuit In High Speed Railway Station

The insulation joint of the track circuit in the high-speed railway station is an important basic equipment to ensure the normal operation of the track circuit in the station.Due to the complex railway and many connecting lines in the station,we still use the traditional mechanical insulation joint as the dividing equipment of the track circuit in the station.The fault of the insulation joint will lead to the cross-coding of the track circuit and affect the normal operation of the train.In this thesis,Based on the phenomenon of insulation joint burning loss as the main research problem,first through the electric contact theory and Hertz contact theory to calculate wheel-rail contact resistance.then through the calculation of the wheel-rail voltage and the temperature of the wheel-rail arc ability to burn insulating section to analysis insulating joints loss problem quantitative and qualitative.finally through the establishment of the integrated grounding system to find the methods to solve the problem of insulation joints burning breakdowns.The specific content is as follows:(1)Calculation of wheel-rail contact resistance.Aiming at such as the wheel-rail contact resistance calculation is not accurate enough,which make deficiencies in the related parameter of wheel/rail arc error.first,this thesis proposed a method,which though the ANSYS finite element analysis software to analyze the macro-contact area of wheel-rail,and calculated the wheel-rail contact resistance through Hertz contact theory combine with electric contact theory,thus analyzed the influence law of different load conditions on wheel-rail contact resistance.(2)Calculation of contact spot voltage.In order to solve the problem that the maximum point of wheel-rail voltage is not found accurately in the existing research,In this thesis established the current density equation on wheel-rail contact spot by analogy with the rolling contact theory,and determined the maximum point of current density on the contact spot.Finally,combining the discharge current,wheel-rail contact resistance and related parameters,obtain the voltage generated at wheel-rail contact spots under different traction current discharge.(3)calculation of insulation joint burning loss.In order to find out exactly the mechanism of the insulation joint burning loss and put forward the corresponding improvement measures,firstly,this thesis calculate the temperature of the arc generated by different voltage levels,and find the change rule of the arc temperature with the distance from the center of the arc column.Then,calculate the carbonization ratio of insulation joints at different temperatures by analyzing the insulation properties of insulating joints.Using ANSYS finite element analysis software establishes the heat transfer model of insulating joint material,and analyze the heating situation of insulating joint when different temperatures act on the surface of insulating joint.(4)Study on solutions.In this thesis,establish the simulation model of the train integrated grounding system in the PSPICE,analyze and calculate the discharge current of the train under different traction levels,and through two improvement methods determine the optimal solution of insulation joint burning loss,which provides theoretical basis and effective improvement measures for solving the problem of insulation joint burning loss on site.The results show that the influence of load condition on the wheel-rail contact resistance can not be ignored.The larger the traction current discharge onto the rail through wheel-rail contact,the larger the high temperature area of the arc will be,and it has been proved that the loss of insulation joint burning occurs because of the repeated action of the low-level arc.The improvement measures in this thesis can effectively solve the problem of insulation joint burning.