Characteristics of levitating X-Y transporter using HTS bulks

High-T_c superconducting bulk has been used for magnetic levitation systems such as a flywheel energy storage system and noncontact transport system. We have been investigating the electromagnetic behavior of high temperature superconductor (HTS) bulks to realize a X-Y (two-dimensional) magnetic levitating transporter without any fixed guides. We have investigated qualitatively the characteristics of the lift and the restoring force of an YBCO bulk under various field-cooling conditions and permanent-magnet arrangements. In this paper, we evaluate the most suitable four-permanent-magnet arrangement through lift and restoring force measurements and numerical analysis by the finite element method (FEM) using the current vector potential.