Due to the large levitation force or the large guidance force of bulk high-temperature superconducting magnets (BHTSMs) above a permanent magnet guideway (PMG), it is reasonable to employ pre-magnetized BHTSMs to replace applied-magnetic-field-cooled superconductors in a maglev system. There are two combination modes between the BHTSM and the PMG, distinguished by the different directions of the magnetization. One is the S-S pole mode, and the other is the S-N pole mode combined with a unimodal PMG segment. A multi-point magnetic field measurement platform was employed to acquire the magnetic field signals of the BHTSM surface in real time during the pre-magnetization process and the re-magnetization process. Subsequently, three experimental aspects of levitation, including the vertical movement due to the levitation force, the lateral movement due to the guidance force, and the force relaxation with time, were explored above the PMG segment. Moreover, finite element modeling by COMSOL Multiphysics has been performed to simulate the different induced currents and the potentially different temperature rises with different modes inside the BHTSM. It was found that the S-S pole mode produced higher induced current density and a higher temperature rise inside the BHTSM, which might escalate its lateral instability above the PMG. The S-N pole mode exhibits the opposite characteristics. In general, this work is instructive for understanding and connecting the magnetic flux, the inner current density, the levitation behavior, and the temperature rise of BHTSMs employed in a maglev system.

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Bulk high-temperature superconductors with a rectangular shape are easy to realize a compact assembly, which is promising for maglev applications. In order to find a reasonable array pattern, we have studied the levitation force of four multiseeded rectangular YBaCuO blocks with three possible arrays above two different permanent-magnet guideways (PMGs). Experimental results show that the levitation force can be improved by optimizing the array pattern of the bulk superconductors. An effective method to improve the utilization rate of the applied magnetic field is to avoid the joint air gaps between bulks located in a strong magnetic field area of the PMG. The optimal array pattern is able to enhance the levitation performance of the present superconducting maglev vehicle.