Study On Galloping Response Of Additional Conductors Of OCS In Strong Wind Section And Effectiveness Of Triangular Anti-galloping Device

Lanzhou-Xinjiang High-speed Railway passes through the world-famous four wind areas in the inland.The environment in the wind area is strong winds occur frequently,causing serious harm to the facilities and train operation safety along the high-speed railway.In order to ensure the stable operation of high-speed trains,a wind barrier is set on the windward side of high-speed Railway subgrade in the wind area.The wind barrier has an obvious accelerating effect on the incoming wind,resulting in the violent galloping of the additional conductors.On the one hand,it is easy to cause the insufficient insulation distance of the additional conductors,resulting in the tripping fault of the substation,on the other hand,it is easy to cause the wear of the connecting hardware at the clamp,fatigue and strand breaking,resulting in wire dropping,short circuit and other accidents,which seriously affects the safe operation of Lanzhou-Xinjiang High-speed Railway.Therefore,this thesis analyzes the galloping response of additional conductors of overhead contact system(OCS)and antigalloping device,so as to provide a strong guarantee for the safe passage of LanzhouXinjiang High-speed Railway.Firstly,by comparing the wind tunnel test and corresponding scale model simulation results of the wind speed change before and after the wind barrier,verify the correctness and effectiveness of the full-scale model simulation method.Establish the overall model of the positive feeder and protective line under the subgrade wind barrier,and divide the grid of the calculation domain into blocks,and use the fluid calculation software to solve the lift and resistance coefficient,wind speed amplification coefficient and wind attack angle of the positive feeder and protection line under different inlet wind speeds.Simulate the random wind field at the additional conductors of OCS,modify it through the aerodynamic characteristics of the additional conductors,and establish the calculation formula of the aerodynamic load of the additional conductors under the influence of the wake of the wind barrier,so as to provide the basis for the subsequent analysis of the galloping response and the anti-galloping effect of the anti-galloping device.Secondly,the horizontal parabola method in the analytical method is used to solve and calculate the position of the additional conductors when the uniformly distributed dead weight load and horizontal tension reach static equilibrium.The static model of additional conductors is established by finite element software and form finding analysis method,and compared with the analytical solution of OCS curve model to verify the correctness of the static model of additional conductors.Then the nonlinear equation calculation method is used to solve the galloping equation,and the effects of span,initial tension and damping ratio on the galloping amplitude of additional conductors are analyzed.The results show that when the span decreases,with the increase of initial tension and damping ratio,the galloping amplitude of additional conductors of OCS.Finally,according to the additional conductors of OCS and the spatial position characteristics of wind barrier,a new triangular anti-galloping device suitable for the lines are designed.The finite element model of triangular anti-galloping device installed on additional conductors is established,the galloping response before and after installing triangular antigalloping device on additional conductors is analyzed,and the anti-galloping effect is compared with that of cable-stayed insulator anti-galloping device.The results show that the triangular anti-galloping device can simultaneously suppress the galloping of two lines in the full-span,and greatly reduce the dynamic tension caused by conductor galloping,and the antigalloping effect is remarkable.At the same time,it is proved that the restraining effect of triangular anti-galloping device on the galloping amplitude of additional conductors and the traction force of wind barrier is better than that of single cable-stayed insulator.