Presentation Information
[AP8-03]Vibration attenuation characteristics of high-temperature superconducting bulks under free levitation and compensation method
*Peiyu Yin1, Tianyu Xing1, Zihan Wang1, Can Peng2, Zigang Deng1 (1. State Key Laboratory of Rail Transit Vehicle System, Southwest Jiaotong University (China), 2. School of Information Science and Technology, Southwest Jiaotong University (China))
Keywords:
High-temperature superconducting maglev,Vibration attenuation,Free levitation,Levitation force compensation,Permanent magnetic levitation
In recent years, high-temperature superconducting (HTS) maglev has progressed from the theoretical research to the engineering development. In practical applications, the maglev train subject to a number of factors, including the unevenness of the permanent magnet guideway (PMG), aerodynamic effects, vehicle-track-bridge coupling and other excitation vibrations. These factors result in internal energy loss of HTS bulks and levitation height attenuation, which potentially threaten the safety of high-speed maglev system. In this study, firstly, a three-dimensional PDE model for vibration attenuation of the HTS bulks under free levitation is established, and the vibration responses of the bulks (including changes in levitation height and current density) under different vibration frequencies, amplitudes, field cooling heights, and working heights are investigated. Based on this, the variation function of HTS bulks levitation height attenuation with time is derived. Then, a permanent magnet onboard (PMO) array that can effectively complement the attenuation of HTS bulks is optimally designed and the working height function of the PMO array under the influence of different parameters is derived. Finally, a free levitation experimental device is constructed to investigate the vibration attenuation characteristics of the HTS bulks and the dynamic characteristics of the hybrid system with the addition of the PMO array. It is found that the levitation height attenuation of the HTS bulks is not directly proportional to the vibration frequency. The attenuations are more significant at 7 Hz and 14 Hz, and smaller at 15 Hz and 20 Hz. This phenomenon is attributed to harmonic resonance of the HTS bulks at 7 Hz and 14 Hz. The height attenuation in multiple-frequency vibration is 133% larger than that in non-multiple-frequency vibration, while the height attenuation with the addition of the PMO is reduced by 57.1% and 33.3% respectively. This article shows the variation law of levitation height of HTS bulks under the influence of different vibration conditions. It also proves that the PMO is an effective compensation and safety redundancy for the HTS maglev, which to some extent can show that the HTS maglev has the potential of long-term high-speed stable operation.