Eddy Current Analysis of Superconducting Magnets for Magnetically Levitated Trains -- Influence of Ground Coil Harmonics

Abstract

For the practical design of the superconducting magnet for high speed trains, the heat encroachment to the liquid helium and the mechanical deformation of the magnet must be solved.
Our purpose is the estimation of very small Joule loss in the liquid helium vessel and magnetic force distribution caused by the ‘6-th harmonics’ flux from the ground coils for levitation. To estimate this small loss and magnetic force distribution accurately, a big scale 3-dimensional analysis considering the complex structure is necessary. However, the full model of the magnet couldn't be analyzed. The conventional thin conductor approximation method cannot solve this model accurately, because the vacuum vessel is thicker than its skin depth.
In this paper, by using the finite element method with edge elements and EWS mounted full memory 512MByte, the small loss, magnetic force distribution and eddy current phase varying on thickness of the vacuum vessel is solved accurately.