312 Ë 8 New progress of HTS Maglev vehicle
Fig. 8.53:(a) Magnetic field distribution (z=15 mm) of the double-pole Halbach PMG. (b) Guidance
forces at different working center lines of an on-board superconductor above the Halbach PMG.
The superconductor sample was a bulk YBaCuO, 50 mm in diameter and 12 mm in thickness
(FCH=30 mm and WH=15 mm).
range ofx>0 mm is set as the outside PMG part for the future HTS Maglev with a curve
a guide in order to produce a faster increase of the guidance forces and better curve
negotiation ability to avoid the vehicle’s lateral displacement along the curve.
As shown in Fig. 8.54, first from the view of the magnetic field distribution,
the additional outside PMs widen the range of the strong horizontal magnetic field
density,Bx. The guidance forces correspondingly become much bigger so that the
lateral eccentricity of the levitated superconductor or vehicle due to a centrifugal
effect is greatly inhibited along the curve. Moreover, as shown in the magnetic field
distribution profiles of PMG I (b) and PMG II (b), with more PMs assembled to the
outside part of the existing PMG, the magnetic circuit becomes a multi-pole structure.
The potential-well effect of the vertical magnetic field density,Bz, is produced to
further inhibit the lateral eccentricity over PMG I (b) or PMG II (b). These important
changes of the magnetic circuit of the PMG will result in a larger guidance force and
better curve negotiation ability.