Development of HTS trapped field magnet using 2G HTS coated conductors

Rights statement
Awarding institution
  • University of Strathclyde
Date of award
  • 2024
Thesis identifier
  • T16852
Person Identifier (Local)
  • 202053604
Qualification Level
Qualification Name
Department, School or Faculty
  • Compact High-Temperature Superconducting (HTS) trapped field magnets stand at the frontier of breakthroughs for advanced industrial equipment, medical devices, and transportation electrification, offering capabilities that conventional permanent magnets and electromagnets cannot achieve. While superconductors capitalize on zero resistance to uphold high currents, thus generating substantial fields, traditional HTS bulks and stacks have been limited by constraints such as geometry size and mechanical robustness. As second-generation (2G) commercial HTS coated conductors advance, there's a growing emphasis on utilizing these tapes to attain expansive and stable trapped field profiles. This thesis explores the innovative magnetization mechanisms and design optimizations of HTS trapped field magnets fabricated with 2G HTS tapes through a comprehensive analysis of HTS-stacked ring magnets, hybrid HTS-stacked ring design, their mechanical stress responses, and trapped field closed-loop HTS coil under field cooling magnetization. The research primarily investigated a novel hybrid HTS trapped field magnet, integrating HTS-stacked ring magnets with HTS bulks to surpass traditional size limitations and achieve a significant trapped field of 7.35 T. It further predicted their capability to generate a trapped field exceeding the applied field due to unique induced current distributions and flux redistribution. Additionally, the study addressed the mechanical challenges posed by Lorentz forces during magnetization, presenting 3D numerical models to analyze stress and strain in HTS-stacked ring magnets. A 90 % stress reduction was seen by proper impregnation and fixation methods. Lastly, a novel closed-loop HTS coil approach was introduced, achieving a compact high-field superconducting magnet that trapped a central field 4.59 T which was higher than the 4.5 T applied field, showcasing potential for diverse high-field applications. Above the inner edge of the HTS coil, the trapped field exceeded the applied field by 1.5 T. This thesis combines experimental findings and numerical modelling to advance the understanding of HTS magnetization processes, offering insights into designing more efficient and durable compact and portable HTS magnets for applications in nuclear magnetic resonance, Maglev transportation, and HTS machinery
Advisor / supervisor
  • Zhang, Min
Resource Type
Date Created
  • 2023