Research On Vibration Control Of Railway Catenary System Based On Damping Compensation

With the continuous increase of the running speed of EMUs,the vibration behavior of the catenary under loads of pantographs and wind and its interaction performance with pantographs under the wind load becomes more and more complex,which directly affects impacts the current collection quality of the pantograph-catenary system.How to improve the dynamic performance and the operation stability of the catenary system at a higher speed and under more complex conditions has become the key issue to ensuring the current collection quality of the pantograph-catenary system.At present,the existing researches mainly focus on parameter matching,systematic optimization,and pantograph control of pantograph-catenary,but the problems of aggravated catenary vibration and the deterioration of catenary vibration and the resulting decline reduction of system service life with the increase of train speed haves not been solved.Damping is an inherent anti-vibration property of a system.Various damping compensation devices based on the principle of vibration-absorbing damping have been widely used in bridges,transmission lines,large buildings,and other structures to suppress structural vibration and improve structural stability.In this paperthesis,the application method and effect of damping compensation devices in electrified railway catenary are studied.The main work of this thesis includes the following aspects.Firstly,based on the nonlinear finite element simulation model of the pantograph and catenary system,the influence of catenary structural parameters,pantographs structural parameters,and catenary damping ratio on the current collection quality is analyzed.The results show that when the pantograph is determined,the fluctuation amplitude of the contact force between the pantograph and catenary decreases with the increase of the utilization rate of the wave speed,and it is positively correlated with the vibration fluctuation amplitude of the contact wire.Increasing the structural damping ratio andof the catenary’s damping can restrain the catenary’s vibration amplitude and improve the current collection quality of the pantograph-catenary systemreduce the contact force’s fluctuation amplitude.Secondly,the damping compensation method,the effect of damping,and the optimal damping layout scheme of dampers in the catenary are comprehensively studied based on the finite element simulation.The established model of the pantograph-catenary system is used to analyze the application effect of catenary damping components.The influence of steady arm damping and dropper damping on current collection performance is also quantified.For the steady arm damping,the influence of damping value on current collection performance at different operation speeds is studied,and the optimal damping values of the steady arm under different speeds are given.For the dropper damping,the influence of dropper damping arrangement on current collection performance is studied,and the optimal dropper damping values and the optimal locations are determined.The results show that proper steady arm damping can reduce the fluctuation of the contact force fluctuation of the trailing pantograph.Still However,excessive steady arm damping may cause lead to hard spots and aggravate the contact force fluctuation between the pantograph and the catenary.The optimal value of the steady arm damping varies with the train speed,and the optimal damping valueit needs to be determined carefully according to the running speed of a given line.The dropper dampinger introduced into the first half span of the catenary can effectively reduce the contact force fluctuation,but the dropper damper damping in the second half span has leads toa negative effects.Furthermore,the damping components for the catenary are designed and developed,and the influence of damping compensation components on the characteristics properties of catenary vibration and wave propagation is analyzed through field tests.According to the simulation results,the idea design of a double rod damping compensation devices for high-speed railway catenary is proposed,and the damping devices for the steady arm damping and dropper damping devices are designed and manufactured,respectively.Then,the suppression effects of the steady arm damping devices and dropper damping devices on the vibration and wave reflection are tested and verified,respectively.The results show that damping compensation at the steady arm and dropper can effectively restrain the catenary’s vibration amplitude while increasing the structural damping of the catenary structure’s damping ratio,which is conducive to maintaining stable contact between the pantograph and the catenary.Proper damping compensation at the catenary steady arm and dropper can reduce the catenary wave reflection coefficient and improve the current collection quality.The damping compensation The suppression effect on wave reflection has a positive correlation with the damping compensation value in restraining the wave reflection when the damping value is selected properly.However,excessive damping compensation can may lead to the increased rigidity of the steady arm and dropper,intensifying the wave reflection effect.Finally,the aerodynamic coefficient of the worn contact wire is obtained by wind tunnel testsexperiments,the galloping phenomenon of the catenary contact wire is reproduced in the simulation,and the application value of the designed damping devices in the suppression of the galloping behavior of the contact wire is analyzed.According to the excitation principle mechanism of catenary galloping,wind tunnel tests experiments are carried out to measure the aerodynamic coefficient of the worn contact wire.The galloping behavior of the catenary under different wind attack angles is studied through numerical simulation.The restraining effect of dropper damping on catenary galloping amplitude is analyzed quantitatively by introducing it into the numerical model.The results show that the Den Harto coefficient of the contact wire sectional profile becomes negative when the wind attack angle is set around 7 °,which will inject negative damping into the system,leading to galloping phenomena and endangering the service safety of the contact wirecatenary.The damping dropper’s suppression effect on galloping becomes more and more significant with the increase of damping value.When the damping value of the dropper reaches a certain valuethreshold,the maximum galloping amplitude of the contact wire is basically the same as the value of the shaking amplitude,and the galloping behavior is not that longer dangerous.In conclusion,theis paper thesis proposes the catenary damping compensation method and the design scheme of damping devices.The proposed damping compensation method can effectively improve the current collection quality of the pantograph-catenary system.Meanwhile,the designed damping devices have positive contributions applications in restraining the catenary’s wave reflection and preventing the catenary’s galloping behavior,which can provide some reference for the design of new catenaries and the modification of the existing catenary in China.