Dynamic Modeling Of The Medium Speed Maglev Train And Research On The Guidance Ability

Through the development over the past half of century,the EMS low-speed maglev train has gradually been developed to commercial application.With the advatanges of low noise,no abrasion and so on,the EMS low-speed maglev train has obtained more and more concerns.The adopted LIM in the traction system limits the running speed,and the energy utilization rate is also low.In view of that,EMS medium-speed maglev train has been developed in National University of Defense Technology by adopting the low-speed levitation & guidance structure and LSM traction system,which is expected to reach the speed of 200km/h.However,it is unknown whether the dynamic performance and guidance ability satisfy the practical needs when the speed is 200km/h.Therefore,the key dynamics problems of medium-speed EMS maglev train including the dynamic modeling of the whole vehicle,the acquisition of the accurate electromagnetic force,the guidance capability under strong crosswind disturbance and track irregularities,are discussed in this paper.The main contents of this paper are given below:1.Based on the analysis of the structure of the EMS medium-speed maglev train system,by viewing the levitation module and the car body as rigid body,the moving coordinate system of rigid part is defined and then the motion equations of every rigid body are established by Newton-Euler method.Omitting the mass of the second suspension system,the air spring is equivalent to the spring-damper system.Then,the calculation formulas of the second suspension force are given.The model of mechanical guiding unit is analyzed and the transfer relationship of guiding force and constraint equations between the car body and suspension module are obtained.The dynamic equations with independent variables are gotten by eliminating the constrained force in the motion equations.Ultimately,the dynamic model containing the vertical and the lateral movements of the mechanical structure of the mid-speed maglev train is obtained.2.The position relationship between the suspension module and the track in different line conditions are analyzed,and the calculation model of electromagnetic force is simplified as the case that there is only lateral offset between the electromagnet and the track.Considering the magnetic saturation and the magnetic flux leakage,the electromagnetic field intensity formula is modified by FEM simulations.On this basis,the more precise analytic formulas of static levitation force and guidance force are obtained.The source of the lateral electromagnetic damping between the electromagnet and the track are analyzed for the first time,and the formulas for calculating the lateral electromagnetic damping force are given.Finally,the expressions of electromagnetic force and torque are listed.3.Dynamic simulation model of the medium-speed maglev train is established when the train run on the straight track.The simulation results are compared with the actual operation results of CMS04 low-speed maglev train in Tangshan test line,which verifiy the accuracy of the maglev train dynamic model established in this paper.4.The dynamic responses of the medium-speed maglev train at 200km/h speed are gotten under the consideration of strong crosswind and track irregularities.Therfore,the dynamic characteristic and guidance ability of the medium-speed maglev train is evaluated according to the security and stability evaluation indexes of track transport.On this basis,the accuracy demands of the maglev track are proposed.The established dynamic model of the EMS medium-speed maglev train in this paper is verified by experimental test.Based on that,the evaluation of the guiding ability and the proposed demand of track accuracy can give an instruction for the design of the vehicle system and track laying,which has a certain engineering value for practical application.