Study On Dynamics Optimization Of The Moving Mechanism Of Medium Speed Maglev Train With Mid-mounted Linear Motor

With the commercial operation of Medium and low speed maglev train in Beijing,Changsha,more and more attention has been paid to the maglev train as a new type of rail transit systems.Funded by the National 13 th Five-Year Key Research and Development Program,this paper studies the dynamics of the moving mechanism of the medium-speed maglev train with mid-mounted linear motor for 200 km/h operating speed based on the virtual prototyping simulation technology.Such maglev trains have U-type electromagnets for electromagnetic suspension and guidance,and hollow long stator permanent magnet synchronous linear motor traction and braking.The main contents of this paper are given below:1.The simulation model of suspension and landing of maglev bogies is built.The performance of anti-rolling and decoupling is analyzed by system simulation.The virtual prototype dynamic simulation model of maglev bogies is established by using commercial multi-body dynamics analysis software LMS Virtual.Lab Motion.Based on the analysis of anti-rolling line stiffness and decoupling line stiffness which are easy to measure,the anti-rolling angle stiffness and decoupling angle stiffness are defined to characterize the anti-rolling decoupling performance of suspension frame,and the quantitative relationship between the angular stiffness and the line stiffness is derived.The simulation method of anti-rolling line stiffness and decoupling line stiffness is established.The correctness of the proposed method is verified by simulation virtual experiment.The simulation results show that the electromagnetic guiding force of U-type electromagnet is beneficial to increase the anti-rolling stiffness of suspension frame in suspension state.The influence laws of motor hanging spacing,motor hanging stiffness and motor roll stiffness on anti-rolling stiffness and decoupling stiffness are simulated and analyzed.The simulation analysis shows that the anti-rolling and decoupling performance of the maglev bogies with mid-fixed motor is mutually constrained.The anti-rolling stiffness and decoupling stiffness are mainly controlled by the motor hanging stiffness and motor roll stiffness,and appropriately reducing the hanging stiffness and increasing the roll stiffness can better compromise between anti-rolling and decoupling stiffness,so that the maglev bogies can achieve better anti-rolling and decoupling effect.2.The simulation model of air spring,height valve and the air suspension system is established,and the correctness of the air spring model is verified by comparison with experimental test data.Based on the commercial software LMS Imagine.Lab AMESim,the simulation models of air spring and height control valve are established.The virtual simulation experiments of vertical load characteristics,static stiffness and dynamic stiffness are carried out.Finally,the results are basically consistent with the experimental results,and the correctness of the model is verified.Aiming at the delay and no induction zone characteristics of the height valve,the simulation modeling and virtual experiment verification are carried out,and the height valve parameters satisfying the standard requirements are obtained.3.A dynamic simulation model of medium-speed maglev train with group control air suspension system is established,and the characteristics of different group control air suspension system are simulated and compared.The multi-body dynamic simulation model of maglev train is established by Motion,and the simulation model of air suspension system with different grouping control is established by AMESim.Through the joint simulation of Motion and AMESIM,the characteristics of three-point air suspension system with side valve,three-point valve in middle valve,four-point air suspension system without differential pressure valve and four-point air suspension system with differential pressure valve are compared and analyzed.The original group C air spring height valve is arranged on the side of the maglev train with three-point air suspension system,which has the problem of excessive ventilation of group C air spring when it slowly comes out of the circular curve.three-point valve in middle valve scheme for the arrangement of group C height valves in the center line of the car body is proposed,which can effectively solve the problem.Although the four-point without differential pressure valve scheme of dividing group C air spring into two groups can also solve this problem,it will bring about the problem that the load difference of each group is too large.Adding differential pressure valve between two groups of air spring at the front end and back end can limit the load difference between each group and reduce the roll angle of the car body when under speed passes through the curve.The research results of this paper can provide theoretical guidance for the development of the mid-fixed-motor medium-speed maglev train engineering prototype and provide a theoretical basis for optimizing the anti-rolling and decoupling performance of the maglev bogies and the air spring group control method.