Y. Fukasawa et H. Ohsaki, Three-dimensional structure of magnetic field in the mixed-mu levitation system using bulk superconductors, IEEE APPL S, 9(2), 1999, pp. 980-983
A permanent-magnet type mixed-mu levitation system, which only needs an iro
n, permanent magnets and bulk superconductors, can realize an advantageous
levitation system, for example, for transportation over a relatively long d
istance because of its simple structure and stable levitation without activ
e control. A three-dimensional numerical analysis of electromagnetic force
characteristics in the mixed-mu levitation system is carried out and the re
sults of the analysis are compared with the experimental. From these result
s we have confirmed that the three-dimensional structure of magnetic field
and the electromagnetic performance of superconductors strongly influence t
he characteristics of the electromagnetic force acting on the iron, which b
ecome unstable in some cases.