High temperature superconducting (HTS) pinning maglev is considered to be one of the most ideal levitation techniques for high-speed transportation in future since its passive and self-stabilizing properties. An efficient and economical propulsion method is important for HTS pinning maglev system. This paper presents a novel HTS pinning maglev system employing a homopolar linear synchronous motor (H-LSM), which shows great potential for engineering. First, conceptual structure of the novel HTS pinning maglev system employing H-LSM is described. The H-LSM was designed to drive a 19-ton HTS pinning maglev engineering prototype using analytical and finite element methods. Then, a comparative performance and cost between H-LSM and permanent magnet linear synchronous motor (PM-LSM) is analyzed. Finally, in order to fully analyze the potential and electro-mechanical coupling of the system, a lateral dynamic response analysis is introduced. The result shows that the novel HTS pinning maglev system employing a H-LSM has a good propulsion-levitation-guidance (PLG) performance. The H-LSM can meet the propulsion requirements of HTS high-speed maglev vehicles with lower cost. The dynamic analysis shows that this new HTS pinning system employing H-LSM has good macroscopic performance for high-speed operation.

High-temperature superconducting (HTS) maglev, owning to the capability of passive stabilization, is potentially promising for high-speed transportation. The guidance force of bulk HTS materials above a permanent magnetic guideway has a nonlinear response due to the hysteresis effect. As a kind of rail transit, when the vehicle runs along the track, the curve and other disturbances will cause vibrations to the vehicle system. These physical factors will pose dynamic loads on the components, reducing structural reliability as well as affecting the ride comfort. The lateral motion, as an important part of the vehicle system dynamics, needs to be studied in the pursuit of HTS maglev realization. In this paper, we first measured the guidance forces of HTS bulks under different motion conditions, and analyzed the relationship between the lateral displacement, the movement velocity and the guidance force. Then, a mathematical model was built based on these experimental data. The key feature of this mathematical model is that it can describe the hysteresis characteristic of the guidance force. Based on this model, we investigated the lateral motion stability of the HTS levitation system, and found three singular points, one stable focus point, and two unstable saddle points. Lastly, a phase portrait was proposed to indicate the safe working region of the HTS maglev vehicle where the vehicle can automatically return to its equilibrium position. These experimental and simulation results are important to clarify the lateral motion stability under external disturbance or shock, and provide a reference basis for the design of levitation systems.

In order to put the practice of high temperature superconducting (HTS) Maglev vehicle technology into people's life, the interaction between high temperature superconductor (HTSC) and permanent magnet guideway (PMG) as the basic model of HTS Maglev vehicle was carefully investigated and enhanced from three essential aspects, i.e., bulk HTSC material, PMG field and bulk HTSC magnetization. The maglev experiments were performed with three kinds of bulk HTSC materials, two kinds of PMGs and two kinds of magnetization methods. It is found that three aspects are all very effective to improve the levitation capability and lateral stability. With better bulk material, more reasonable PMG configuration and magnetization method, the performance of HTS Maglev vehicle system will be greatly advanced and closer to an economical and practical level.

The levitation-propulsion integration ability of radial permanent magnet electrodynamic wheel (PM EDW) renders its competitive edge over other magnetic levitation systems. A low-cost and effective second induction method is proposed to target the synchronous improvement of the saturation speed, levitation and propulsion forces. Its effectiveness is determined from the small-scale EDW to the full-scale EDW via theoretical model, simulation analysis and experiments test. First, according to magnetic charge theory, an updated EDW is proposed and developed. Simulated and tested results of the small-scale EDW demonstrate that the levitation force, propulsion force and saturation speed are increased by 14%, 7% and 30%. This improvement benefits the increased induction current and the mitigated skin effect. Afterwards, further analysis of the full-scale EDW with rings of various conductivity and thickness is conducted. The levitation force, propulsion force and saturation speed are enhanced by more than 50%, 10% and 200% synchronously. Based on analysis of power loss under the same levitation and propulsion forces, the updated EDW is more efficient than the original EDW. Ultimately, a proof-of-principle prototype with the updated EDW and 4-m long guideway are developed. The multi-loop PID control strategy along with dynamic mode implementation methodology are introduced. The scaled prototype is levitated over guideway at 12 mm and the levitation-propulsion ability is implemented with the maximum acceleration of 1.25 m/s ² . This proof-of-principle prototype with updated EDW and control strategy paves the way to engineering applications of Maglev car.

AbstractWith regard to the state-of-the-art technologies in the fields of applied superconductivity and electromagnetic devices, research and development highlights are presented. The recent progress and achievement described with principle and technical details include mainly i) applied superconducting materials; ii) superconducting magnets and their applications such as in ITER and Tokamaks; iii) high Tc superconducting (HTS) magnetic levitation and applications; iv) HTS smart grids; v) superconducting and electromagnetic material modelling and characteristics; vi) advanced electromagnetic devices. The applied superconductivity technology and availability are especially focused and verified with the trend of its development prospection.