Enhancing dynamic stability of HTS maglev systems with preloading method

• Published in: Cryogenics (Guildford) Vol. 143; p. 103945
• Main Authors: Hong, Ye, Huang, Zhichuan, Wang, Zihan, Zhang, Jiwang, Zheng, Jun
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.10.2024
• Subjects: Guidance performance; HTS maglev; Levitation stability; Position offset; Preloading; Position offset; Guidance performance; Preloading; Levitation stability; HTS maglev
• ISSN: 0011-2275
• DOI: 10.1016/j.cryogenics.2024.103945

•The magnetic field of a Halbach guideway was derived, and a model for HTS maglev systems’ dynamic response was built.•The gain effect of preloading on levitation force and guidance force of HTS bulks during lateral movement was clarified.•The suppressive effect of preloading on the levitation drift of HTS bulks after disturbance was determined.•It was found that preloading increases the maximum excitation force threshold for system instability. High temperature superconducting (HTS) bulks have strong flux pinning capabilities and are widely used in various fields. Their self-stabilizing characteristics also provide new ideas for ultra-high-speed rail transit. For HTS maglev systems, operational stability, curve negotiation and safety when subjected to external forces are very important. Due to the hysteresis effect of superconducting bulks, they do not always return to their initial positions after deviating from the levitated position in an alternative external magnetic field. In some cases, the levitation system can be destroyed. Studies have shown that preloading can enhance quasi-static levitation performance. Therefore, this paper conducts a detailed analysis of the quasi-static levitation and guidance forces of HTS bulks above a Halbach permanent magnet guideway (PMG) under conditions with and without preloading. Additionally, the dynamic responses of the HTS bulks under lateral or vertical pulsed excitations are studied, with a particular focus on the final equilibrium position offset after disturbance. The results indicate that preloading can suppress the attenuation of the levitation force, enhance the guidance performance, and raise stiffness in both lateral and vertical directions. It also effectively suppresses position deviation from disturbance and increases the maximum excitation force threshold for system instability. This study provides practical insights for HTS maglev applications.