Study of long-time levitation performance of high temperature superconducting maglev under vertical vibration

Abstract

In order to explore the long-time evolution of the high-temperature superconducting (HTS) maglev levitation force (LF), this paper uses the self-developed HTS dynamic maglev measurement device to conduct a long-time dynamic experiment. Limited by the experimental conditions, further working conditions are conducted based on the dynamic simulation model which is constructed based on COMSOL Multiphysics by using the magnetic field intensity H method and the basic electromagnetic formula of superconductors. The accuracy of the simulation model is verified by 9.5 h of experiment. Based on the simulation model, the LF change and levitation height decay of HTS maglev under the vehicle vibration excitation for a long time are explored. Firstly, considering the self-oscillation frequency of HTS maglev, a comparison of the different working conditions from 0.5 Hz to 10 Hz shows that there is no direct relationship between the LF and frequency in the self-oscillation frequency range. Secondly, a 30 days operation under 0.1 Hz external excitation is calculated to simulate long-time evolution and regularity of HTS maglev, which shows the LF decay has a logarithmic decay regularity with time. Furthermore, to investigate the influencing factors and improve the LF decay, the preload method was carried out. The work can provide a predictive model and data reference for the long-time performance of the HTS maglev engineering vehicle.