Inverted-T-shaped YBaCuO bulks improving high-temperature superconducting maglev performance

The high-temperature superconducting (HTS) maglev system uses the self-stabilizing force for the synchronous levitation and guidance. This unique passive-stable levitation is generated by the induced current of HTS bulks in a gradient magnetic field. The c-axis direction of onboard HTS bulks parallel or perpendicular to the applied magnetic field can improve the levitation force or the guidance force, respectively. Therefore, the new combined laying modes of HTS bulks, inverted-T-shaped and U-shaped arrays of HTS bulks above an applied Halbach permanent magnet guideway (PMG), appeared in order to improve the maglev performance of HTS Maglev system. The interaction among yttrium barium copper oxide (YBaCuO) bulks was investigated experimentally in this paper, which was measured with the difference between the additive method and the direct method. The results indicate that the maglev performance of combined layout HTS bulks does not simply equal to the sum of each single bulk's levitation force or guidance force. The interaction of U-shaped array is much larger than that of the inverted-T-shaped array, which is attributed to anisotropy property of onboard HTS bulks. Since the interaction greatly weakens the magnetic force performance of the U-shaped array, the inverted-T-shaped array is recommended for the refined design of onboard bulks for HTS maglev systems.