Research On Vibration Problems Of EMS Maglev Train Under Steel Structure Track

With the continuous commercial application of medium and low speed maglev trains,reducing the cost and improving the performance are the key issues in the development of future maglev transportation.Considering the fact that track accounts for more than 60% of the total maglev transportation construction cost,it’s a trend to adopt all steel structure track with advantages of low cost,easy processing and laying.This paper focuses on the coupled resonance vibration problem of maglev train which has not been completely solved under the steel track.The solution of this problem has important practical significance in improving the stability of levitation system,reducing the cost of maglev transportation construction and shortening the construction period.Combining the coupling resonance of electromagnet-rail in parking braking condition and the coupling resonance of the maglev train and steel beam in static levitation condition,the resonance mechanism is researched through theoretical analysis,simulation and test respectively,and corresponding vibration suppression strategy is put forward.First,brake,track and electromagnet module in the electromagnet-track coupling system in parking brake condition are studied.The coupling system model of the electromagnet-rail is established by means of theoretical analysis,simulation verification and test,and the coupling resonance mechanism of the electromagnet-rail is discussed.Second,the vibration control strategies based on notch filter and LMS adaptive cancellation algorithm are studied considering the characteristics of the electromagnet-rail coupling resonance in the parking brake condition.The results show that the proposed control method has good vibration suppression effect,which makes the coupling system have better stability and reliability,and is suitable for the application of the medium and low speed maglev traffic system.Then,the coupling resonance problem of maglev train and steel beam is studied.Based on the previous research,stability problem of the full maglev vehicle and steel beam coupling model is analyzed.Through analyzing the influence of the steel beam structural parameters on the coupling system,the conclusion is got: to a certain extent,the coupling system is more stable with higher damping ratio,lower modal frequency and greater line density of the steel beam.This conclusion provides a useful reference for the future structural design of magnetic levitation steel beams.In the end,the coupling resonance suppression strategy of maglev train and steel beam is studied.The coupling resonance suppression algorithm for maglev train and steel beam based on flux derivative feedback is proposed,Then a suppression strategy based on estimated electromagnet position signal feedback is researched.Theoretical analysis,numerical simulation and test have verified the effectiveness of the two control strategies.In this paper,the electromagnet-track coupling model and the maglev train and steel beam coupling model are established,which is necessary for further research of the coupling resonance problem of maglev train under steel track.The proposed coupling resonance suppression strategy provides a new way to solve the coupling resonance problem of maglev train under the steel track.The research work has important practical significance for further commercial application of EMS maglev train.