Study On Dynamic Characteristics Of Hts Maglev Vehicle On Ramp

Based on the flux pinning effect of the second kind of non ideal superconductor,the high temperature superconducting(HTS)maglev vehicle can maintain stable levitation without any control.Therefore,it has the advantages of simple and reliable principle,low energy consumption and environmental friendliness.It is suitable for the development direction of high-speed train in the future.Recently,the first HTS maglev engineering prototype in China has been officially opened in Southwest Jiaotong University,which indicates that the engineering application of the HTS maglev train has reached a new stage.However,there are still many problems to be solved in the process of HTS maglev technology becoming mature.Among them,the design of the line parameters is an important content.This thesis focuses on the dynamic response of HTS maglev vehicles passing through the ramp,and the following research work is carried out:(1)Firstly,the levitation force of HTS bulk under long time heavy load is measured.The results show that the levitation performance of HTS bulk is not changed obviously.The experimental data of levitation force are fitted by the double exponential function model.The levitation force curve with high confidence is obtained,which is used for dynamic simulation.(2)The vehicle-line simulation model of HTS Maglev based on ramp operation condition is established.The relationship between levitation force and levitation gap is based on the double exponential function model which is obtained from the above work.Then,the corresponding simulation model is established and calculated by using Universal Mechanism(UM)dynamic simulation software.(3)The dynamic response of HTS Maglev vehicle passing through the ramp under different slope,different vertical curve radius and different vehicle speed is studied.The results show that the dynamic performance of the vehicle passing through the vertical curve deteriorates if the slope is too large.The speed of passing through the vertical curve should not be too fast.The radius of vertical curve should be increased according to the limit of vertical centrifugal acceleration.Transition curve is set at the joint of straight line and vertical curve,the results show that it has good effect on reducing vehicle vibration.At the same time,the Sperling index is used to evaluate the stability of the vehicle running at different speeds and on different slopes.The results show that the stability of the vehicle is "excellent".(4)The effects of different secondary suspension stiffness,damping and body mass on the dynamic performance of HTS Maglev vehicle passing through the ramp are investigated.The results show that the secondary suspension parameters have little influence on the vibration of the vehicle passing through the joint of straight line and vertical curve.But they have more obvious influence on the subsequent vibration attenuation.Increasing the vehicle load don’t aggravate the vehicle dynamic performance,indicating that it has good empty and load vehicle performance in the case of no-load or heavy load.In this thesis,the reliability of HTS Maglev technology is proved by studying the levitation force performance of HTS bulk under heavy load condition.The dynamic response of HTS Maglev vehicle passing through the ramp is studied.Based on it,the reference suggestions for the design of line parameters are provided.