A Design Method of Magnetic Shielding for a Superconducting Magnetically Levitated Train

Abstract

For EDS-type magnetically levitated trains, magnetic shielding of stray fields produced by superconducting magnets is an important task. We seek the ‘optimal’ thickness distribution (configuration) of magnetic material, which is the lightest and keeps the magnetic field at tolerable levels in the vehicle. In many cases, trial and error metohds have been adopted for this purpose. In this paper, we propose a new method for a preliminary design of the magnetic shielding. In this method, we simplify the magnetic shielding problem, assuming the infinite permeability of the magnetic material, and calculate the magnetic flux going into or out of the shield surface. In this case, we can design an optimal magnetic shield (distribution and configuration of the magnetic material) and know the minimum weight of the magnetic shielding. We finally show an example of the magnetic shielding designed by this method and investigate its characteristics in a magnetically levitated train.