Magnetic Characteristics of Nd-Fe-B Permanent Magnets at High Temperature and the Effect of Temperature on High-Temperature Superconducting Levitation Performance

Abstract

In the practical application of high-temperature superconducting (HTS) magnetic levitation, the influence of ambient temperature on its performance is mainly reflected in the change of magnetic characteristics of the permanent magnet guideway (PMG). In order to investigate the magnetic characteristics of the PMG at high temperature and the influence of temperature on the levitation performance of HTS bulk above, we studied the magnetic characteristics of three kinds of PMG and six kinds of single permanent magnet (PM) in the temperature range from room temperature to 85 °C. Furthermore, we investigated the effect of this variation on the levitation performance of HTS bulk under a zero-field-cooling condition. The results show that the N-S-S-N-type PMG-H has better magnetic field stability than the Halbach PMG-I and the N-N-S-S-type PMG-J at high temperature. The levitation force of HTS bulks decreases with the increase of the PMG temperature. The variation range of levitation force is larger than that of magnetic field of PM, but absolute values under 55 °C are small. This work provides a reference for the engineering PMG optimization of HTS magnetic levitation.