Measurement and analysis on the levitation and guidance force of HTS bulks under permanent magnet guideway fluctuating magnetic field

High-temperature superconducting (HTS) pinning maglev technology has attracted considerable attention in the field of high-speed maglev transportation. In practical applications, HTS bulks are subjected to a complex electromagnetic environment due to various external excitations, including the unevenness of permanent magnet guideway (PMG), aerodynamic effects, and normal disturbance of the motor etc. These factors induce variations in the levitation performance of the bulks. In this paper, an air cylinder vibration table with adjustable amplitude and frequency was constructed, and the SCML-01 system was employed to conduct real-time force measurements on the HTS bulks. Experimental results indicate that the levitation force attenuation of HTS bulks increases nonlinearly with the amplitude and frequency of the fluctuating magnetic field (FMF). A resonance phenomenon emerges at 8 Hz, where the levitation force attenuation rate reaches 9.51 %—significantly higher than that at other frequencies. In comparison with the control group, after exposure to the FMF of the PMG, the guidance force of HTS bulks increases significantly, while the unrecoverable distance decreases. This work clarifies the laws governing the influence of the amplitude and frequency of the FMF on the electromagnetic force characteristics of HTS bulks. These findings provide valuable insights for guiding the future development and application of HTS pinning maglev technology.