Experimental investigation on vibration characteristics of the medium-low-speed maglev vehicle-turnout coupled system

The steel turnout is one of the key components in the medium–low-speed maglev line system.However,the vehicle under active control is prone to vehicle–turnout coupled vibration,and thus,it is necessary to identify the vibration characteristics of this coupled system through field tests.To this end,dynamic performance tests were conducted on a vehicle–turnout coupled system in a medium–low-speed maglev test line.Firstly,the dynamic response data of the coupled system under various operating conditions were obtained.Then,the natural vibration characteristics of the turnout were analysed using the free attenuation method and the finite element method,indicating a good agreement between the simulation results and the measured results;the acceleration response characteristics of the coupled system were analysed in detail,and the ride quality of the vehicle was assessed by Sperling index.Finally,the frequency distribution characteristics of the coupled system were discussed.All these test results could provide references for model validation and optimized design of medium–low-speed maglev transport systems.

Carrying capacity for the electromagnetic suspension low-speed maglev train on the horizontal curve

Aiming at the lateral dislocation between the electromagnets and the rails on a horizontal curve,we investigated a single magnetic bogie of the maglev train in this paper.The magnetic levitation and guidance forces supplied by the suspension modules were deduced by the flux tube method.According to the dynamic equilibrium equations of the maglev train on the curved track with cant,several major factors that influence the carrying capacity were analyzed,and the formula of the carrying capacity was presented.The results provide a theoretical reference for the design of maglev train.

Vibration reduction for a new-type maglev vehicle with mid-mounted suspension under levitation failure

Levitation failure occasionally occurs when a maglev vehicle runs on a track. At the moment of levitation failure, the levitation module falls and hits the track, and there is a violent impact on the maglev vehicle-bridge coupled system. In this paper, the response of the maglev vehicle-bridge coupled system at the moment of and after levitation failure is analyzed, and three methods of reducing the vibration are proposed. First, a dynamics model of the maglev vehicle-bridge coupled system, which considers the control system, five flexible bridges, and track irregularity, is established, and the correctness of the model is verified using test data. The system response for different failure cases is then analyzed. Finally, the three methods of reducing vibration under levitation failure are proposed, and their effectiveness is evaluated. The results show that the failure position and speed barely affect the response, whereas the maximum impact forces due to levitation failure reduced by 13%, 63%, and 50% by adopting the three methods, namely connecting the first and third coils in series, coupling the ends of the levitation module vertically, and adopting two sets of anti-roll devices, respectively. When the latter two schemes are combined, the maximum impact force reduced from 133 kN(without vibration-reduction measures) to 9 kN, and the vibration-reduction measure is also effective for failures of the levitation units at the ends of the vehicle.