Magnetic Gradient Levitation using Bulk Superconductors

我们研究了一种磁梯度悬浮系统，该系统以高温体超导体和铁等软铁磁材料为主要组成部分。通过电磁场、力的测量和有限元分析，发现其潜力和有待进一步研究的课题。 1．电磁特性实验研究（1）永磁式混合μ悬浮：对置于块体超导体之间的铁轨施加电磁力的测量，证明块体超导体对电磁力的稳定作用以及恢复力的产生。铁轨越长，电磁力特性越不稳定。(2)体超导磁梯度悬浮：虽然由于超导体的临界电流密度有限，初始施加场的大小影响电磁力的稳定性，但在较低的施加场下获得了恢复力。还观察到铁轨长度对受力特性的强烈影响。 2．电磁特性的数值分析：通过数值分析方法研究了电磁特性对体超导体和铁轨的几何结构、超导体的有限临界电流密度和磁场的三维结构的依赖性。结果与实验结果吻合较好，有助于更好地理解系统中的电磁现象。 3．应用系统：当使用体超导体的磁梯度悬浮应用于线性运输系统时，需要对移动方向上的磁场分量进行屏蔽。磁力轴承应用潜力巨大。

We have studied a magnetic gradient levitation system that has high-temperature bulk superconductors and soft ferromagnetic materials like iron as essential components. Measurements of electromagnetic field and force and finite element analysis were carried out to find its potentials and subjects to be investigated further.1. Experimental study on electromagnetic characteristics(1) Permanent magnet type mixed-mu levitation : Measurements of electromagnetic force acting on an iron rail placed between bulk superconductors proved the stabilization effect of electromagnetic force by the bulk superconductors and the generation of restoring force. A longer iron rail made the electromagnetic force characteristics less stable.(2) Bulk superconducting magnetic gradient levitation : Although the magnitude of an initial applied field influenced the stability of electromagnetic force due to the finite critical current density of the superconductors, the restoring force was obtained for a lower applied field. The strong influence of the iron rail length on the force characteristics was also observed.2. Numerical analysis of electromagnetic characteristics : Dependence of electromagnetic characteristics on the geometrical configuration of bulk superconductors and an iron rail, the finite critical current density of the superconductors and the three dimensional structure of magnetic field were investigated by numerical analysis methods. The results agreed well with the experimental results and gave good understanding of the electromagnetic phenomena in the system.3. Application systems : When the magnetic gradient levitation using bulk superconductors is applied to a linear transportation system, the shielding of the magnetic field component in the moving direction is required. Magnetic bearing application has a large potential.