Experimental And Simulation Research On Three Lumped Mass Model Of High-speed Pantograph

When the high-speed train is running,the pantograph installed on the top of the train supplies energy to the high-speed train through sliding contact with the overhead contact line,the process is also called "current collection".The quality of current collection between the Panhead and contact wire not only restricts the maximum speed of the train,but also affects the service life of the pantograph and catenary system,it can reflect contact status of the pantograph and catenary.The quality of current collection can be evaluated by the contact force of pantograph and catenary.To calculate contact force,it is necessary to establish a reasonable model for the pantograph and then to simulate pantograph and catenary dynamics.With these two points as the goal,the main work and conclusions of this paper are as follows:(1)Using the current mainstream pantograph three lumped mass model,combined with quasi-static loading,free vibration experiment and equivalent energy method calculation,the equivalent mass,equivalent stiffness and equivalent damping of Panhead,upper frame and lower frame are obtained During the experiment,to reduce the experimental error,the experimental steps were strictly standardized,and each group of experiments was carried out at least 3 times.Detailed and reliable data were obtained for subsequent analysis of the influencing factors for lower frame damping,dynamic simulation of pantograph catenary and simulation of three lumped mass model parameters(2)The equivalent damping of pantograph lower frame has an important effect on the contact force of pantograph-catenary.The simulation results show that the increase of the equivalent damping of a lower frame can reduce the standard deviation of contact force between pantograph and catenary,that is,the quality of current collection is improved.However,the influencing factors of lower frame damping are not clear at present.In this paper,two experimental methods,the under spring method and the suspension spring method,is used to conduct a comparative experiment with or without a damper.It is clear that the influencing factors of lower frame damping are:damper,lower arm joint friction,pneumatic actuator,and determined that the proportion of each influencing factor was 47.4%,41.6%,11.0%.Based on the conclusion of this study,a design scheme using double dampers is proposed to reduce the standard deviation of the contact force by 3.7%.(3)The dynamic characteristics of the pantograph will affect contact force between pantograph and catenary.The frequency response function of acceleration/excitation is used to characterize the dynamic characteristics of the pantograph.Based on three lumped mass model of pantograph and the finite element model of two-dimensional catenary,simulating and discussing the contact status of the DSA380 pantograph at the speeds of 250,300,and 350 km/h at the Wu-Guang line.The simulation results show that at 350 km/h speed,the maximum contact force Fmax of the pantograph,Vertical Position Range of the contact point(RVPPC),Maximum Uplift displacement of Steady arm(MUS),the ratio of the standard deviation of contact force and the average value of contact force all meet the requirements of standards,In terms of simulation results,350 km/h is a safe operating speed.Besides,the simulation shows that the standard deviation of contact force,RVPPC,and MUS all increase with the increase of pantograph operating speed.This shows that the faster the pantograph operating speed,the more severe the oscillation between pantograph and catenary.(4)At present,the parameters of three lumped mass model are mainly obtained through experimental tests.Although the experimental data can truly reflect the characteristics of the target pantograph,the test period is long and the cost is high.Also,the parameters of three lumped mass model during the pantograph catenary simulation,the optimized results are not real-time when applied to the actual pantograph.Therefore,the simulation method is used to reproduce the process of the three lumped mass parameter experiment test,and the comparison with the experimental data is used to build an accurate simulation platform.This research idea has a certain significance for reducing the production cost of a pantograph,optimizing the structure of pantograph,saving on-site test time and test funds,and liberating manpower.