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The lateral restorable characteristics of a translational symmetry high- T c superconducting maglev system are investigated by measuring its resonant frequency ( f RF ) after a lateral displacement. The difference between whether this lateral displacement is restorable, meaning elastic or inelastic, is determined by whether or not the maglev body returns to its original position after a lateral displacement. The maximum restorable lateral displacement ( δ MRLD ) is determined by the sudden change of the f RF vs. the maximum lateral displacement ( δ MLD ) curve. The f RF of the high- T c superconducting maglev system with different field-cooling height (FCH) and working height (WH) was obtained from the frequency domain vibration curve which was measured by a vibration measurement system. The results showed that, the δ MRLD was reduced when the WH was decreased. The maximum restorable guidance force ( F MRGF ) was found to not always increase with the lowering of the WH for the same FCH. The lateral restorable stiffness ( k LRS ) was always enhanced with the decrease of the WH. The decrease of the δ MRLD with the WH is interpreted by the fact that, the tangential field component (Δ H ) across the surface of the high- T c superconductor (HTSC) is easier to exceed the J c λ value ( J c is the critical current density and λ is the London penetration depth) when the WH is lowered, and this makes the trapped flux lines become more susceptible in escaping its pinning sites.

In practical application of High- T c Superconducting (HTS) maglev, slant is an observable defect. It was caused by constantly one side on and off the vehicle by passengers. So far, this phenomenon has not been reported yet. In order to understand its influence on the stability of the HTS maglev, we experimentally studied the dynamic characteristic and slant effect of HTS maglev under center-load and side-load. It was found that load destabilizes the vehicle, and the side-load can obviously slant the vehicle body. In the end, the pre-load method was proposed to enhance the dynamic stability and suppress the slant, which proved to be considerably effective. These results are critical in practical running of HTS maglev.