Field models of high‐temperature superconductor devices for magnetic levitation

Abstract

PurposeThe purpose of this paper is to describe a twofold methodology for evaluating the force between field excitation system and bulk in a magnetic‐levitation device based on high‐temperature‐superconductors (HTS). The paper focuses on two‐dimensional field models for HTS bulks. As far as field analysis is concerned, the finite‐element method in two or three dimensions is used. Alternatively, the conformal mapping approach provides a flexible and accurate calculation tool, useful for the optimization of superconducting bearings.Design/methodology/approachPowerful mapping algorithms, developed recently for Schwarz‐Christoffel‐like transformations, have proven successful in analyzing the fields, both in the activation and in the operation condition of superconductor devices.FindingsAssuming small displacements of the superconductor sample with respect to the excitation magnets, the force‐displacement curve was obtained for operational field cooling via Schwarz‐Christoffel maps.Originality/valueThe specific theory used is the substitution theorem for magnetic fields, along with its capability to take complex geometries into account, making it possible to model devices for real‐life applications. Using only a scalar potential, the procedure proposed for computing fields proves, in the conformally‐mapped plane, the superposition method already introduced in FEM‐based models.