The Effect of Running Speed and Guideway Irregularity on the Levitation Performance of a Linear HTS Maglev Bearing

High-temperature superconducting (HTS) magnetic levitation (maglev) bearing is regarded as a promising candidate for the future high-speed transportation system as a result due to the merits of passive stabilization, low power consumption and environmental-friendliness. The dynamic characteristics are critical for its high-speed applications performance. The current research on the dynamic characteristics of linear HTS maglev bearings is limited to small-scale, approximate harmonic excitation or low-speed. In this paper, the expression of random guideway irregularity spectrum in time domain, which could describe the realistic guideway excitation in rail transportation system, was obtained by Inverse Fourier Transform method with a homemade code. Based on a strong-coupled electromagnetic-thermal-mechanical model, the dynamic characteristic of a heavy-load linear HTS maglev bearing under the excitation of random guideway irregularity with different speeds (400, 500, 600 km/h) and guideway irregularity amplitudes were studied. The results show that the influence of high speed and the temperature on the dynamic stability of linear HTS maglev bearing is quite limited, which is contrary to common concern. On the other hand, the guideway irregularity amplitude plays a great effect on the system dynamic stability. Thus cautious attention is still needed when selecting the line route and manufacturing the guideway. These conclusions could serve as a design guideline for the future high-speed application of linear HTS maglev bearing.