Static and dynamic characteristics in levitating X-Y transporter using HTS bulks

High T_c superconducting bulk has been used for magnetic levitation systems such as flywheel energy storage system, noncontact transport system and so on. We have been investigating electromagnetic behaviors of HTS bulk to realize a X-Y (two-dimensional) magnetic levitating transporter without any fixed guides. We have investigated qualitatively the characteristics of lift and restoring force of an YBCO bulk for various field-cooling conditions and permanent-magnet arrangements. In this paper, we evaluated the most suitable conditions of air gap in field-cooling process and permanent-magnet arrangement through lift and restoring force measurements and numerical analysis by the finite element method (FEM) based on the current vector potential method. The characteristics of oscillation in the vertical direction of levitating X-Y transporter were investigated by the measurements of free and forced vibrations. The theoretical characteristics of the free and forced vibrations were compared with the experiments.