Takashi SASAKAWA, Naoto TAGAWA, Toshiki HERAI, Ken NAGASHIMA
For magnetically levitated trains, magnetic shielding is one important
task. Reduction of magnetic field in vehicles is the first priority,
but weight reduction of shielding material comes next. In our
experiment, reduction of magnetic field in vehicles to less than
2mT (20 Gauss) is our immediate target.
In first part of this paper, we display the experimental result
of magnetic shielding in full scale test facility. We confirm
that maximum magnetic flux density is less than 2mT in this experiment.
At the same time, we show that the main reason for local flux
leakage is in misalignment at the connection of magnetic material.
In second part, we propose a design method of magnetic shielding
for weight reduction of magnetic material. We can predict the
minimum weight of magnetic material by this method under simplification
of real magnetic shielding and say that the weight of our test
facility can be further reduced.