High Speed Pantograph-catenary Dynamic Matching Design In Complex Service Environment

The development of high-speed train with 400 km/h puts forward newer,higher and more challenging technical requirements for pantograph-catenary(PAC)matching relationship.Pantograph-catenary matching technology under different operating conditions and service environments forms a key part of the whole technology integration of high-speed train system.Pantograph-catenary matching is essential to ensure safe and smooth operations of high-speed trains.Based on multi-body dynamics and finite-element theory,a refined pantograph-catenary dynamics simulation method of vehicle-pantographcatenary-climate coupling is established in this thesis.Based on the dynamic interaction law of pantograph-catenary system in complex service environment,this thesis makes an in-depth study to the problem in four aspects: the wide adaptability matching technology of pantograph and catenary;the evolution law of pantograph and catenary current collection performance when the ambient temperature changes;the evolution law of catenary vibration characteristics and current collection performance under icing conditions;and finally the dynamic characteristics of pantograph lifting during the train operation.In order to study the parameters matching of pantograph and catenary at a train speed of 400 km/h,a coupled dynamic model of vehicle-pantograph-catenary considering track irregularity is established.Based on Pearson correlation coefficient and frequency spectrum analysis,the key kinematic parameters of vehicle body vibration affecting current collection quality of pantograph-catenary system are identified.Through the analysis of the anti-resonance frequency of pantograph,the mechanism of the influence of train vibration on the current collection quality of pantograph-catenary system is unveiled.The influence of vehicle body vibration caused by track irregularity on current collection quality of pantograph-catenary system can be evaluated by the characteristic frequency and amplitude of vertical vibration displacement of vehicle body.Multi-factor method,which is superior to the single-factor method,is proposed to study high-speed pantograph-catenary matching problem.The mapping relationship between key parameters of catenary and current collection performance index of PAC is investigated using multiple regression method.The multivariate linear model shows that,the correlation between the current collection index of PAC and the selected predictor variables is 97.06%,which is very high from the statistics point of view.Furthermore,using the multivariate polynomial model,the correlation between the current collection index of PAC and the predictor variables attains as high as99.76%.In view of the change of pantograph-catenary dynamic performance caused by the change of ambient temperature,the coupling dynamic model of pantograph-catenarytemperature is established.The influence of ambient temperature on the spatial position of overhead contact system(OCS)is investigated first,then the influence of temperature on the longitudinal,transverse and vertical position of OCS is analyzed respectively.For9-span OCS,when the ambient temperature changes from the design temperature to the limit temperature(-60 ? or 80 ?),the longitudinal position change of OCS can reach as high as 300 mm,while the horizontal and vertical position change of OCS is within 4 mm,which is trivial.In addition,the distribution of cable tension in OCS system is re-configured by the change of ambient temperature.The tension of OCS is mostly affected by the change of ambient temperature.When the ambient temperature increases or decreases to the limit temperature(-60 ? or 80 ?),the tension change of OCS is about 2%.For the catenary with full compensation device,the further the cable is from both ends of the catenary,the greater the influence of temperature change on the cable tension.Under the influence of temperature,the spatial position of catenary and the tension distribution of cable varied,which affects the current collection quality of pantograph catenary system during train operation.Investigation shows that,the current collection quality of pantograph catenary system is significantly affected by the decrease of ambient temperature.When the temperature drops to-60 ?,which is quite common in the extreme cold area,the maximum variation of statistical value of contact force is 4.79%,the maximum variation of lifting displacement of contact piece is 29.47%,and the maximum variation of vibration acceleration of contact piece is 4.78%.In view of the evolution of current collection characteristics caused by icing,three different icing methods,namely,increasing density method,uniform load method and composite material method,are adopted to study the influence of catenary icing thickness on current collection quality of PAC system under different operating speeds.In view of the evolution of current collection characteristics caused by icing,the combined material method is proposed to study the influence of catenary icing thickness on current collection quality of PAC system under different operating speeds,and compared with the traditional methods of increasing density and uniform load.By comparison,the composite material method is the most suitable method to calculate the icing of OCS.The icing of catenary system will reduce the current collection quality of PAC system,and with the increase of train speed and icing thickness,the current collection quality of PAC system will become even poor.When the ratio of catenary icing thickness to cable radius exceeds 2,it is recommended that the train pass the area with reduced speed.Aiming at the collision characteristics between pantograph and catenary in the process of lifting the pantograph during train operation,a pantograph lifting collision model is established.At the same time,a pantograph lifting ground test-rig is built to verify the pantograph lifting collision model.If the pantograph is lifted with the train being stationary,the speed and position of lifting the pantograph will affect the time of lifting the pantograph,the acceleration of the contact piece,the vertical displacement of the contact piece and the collision force between the pantograph and catenary.The maximum collision force between the pantograph and catenary is proportional to the speed of lifting the pantograph.When the speed of lifting the pantograph exceeds 0.5 m/s,the contact force between the pantograph and the contact wire will exceed 250 N,which is the limit of EN standard.The distribution of the dropper will also affect the collision contact force between the pantograph and catenary.Simulation shows that,when the collision point is near the dropper,the local impact force is the largest compared to other locations.When the pantograph is raised up with the train being in operation,not only the lifting speed and position of the pantograph will affect the dynamic action between the pantograph and the catenary,but also the train speed comes into play.Therefore,in order to ensure the safe and smooth pantograph lifting of the train in operation,it is necessary to strictly control the speed of lifting the pantograph,position of lifting the pantograph and train running speed.In addition,aiming at the400km/h railway network,a multi-standard pantograph lifting scheme is proposed.