190 Ë 6 First manned HTS Maglev vehicle in the world
The following will introduce the technical details in the manned HTS Maglev
vehicle “Century”.
6.14 Permanent magnet guideway
The disadvantages of an electrical magnet are the complexity of the guideway and
high electric energy consumption. If the applied magnetic field is provided by an
NPM, a larger levitation force between HTS bulk and the applied magnetic field can
be achieved. The magnetic field of the PMG can be increased by the application of a
flux concentration scheme in the magnet arrangement. In order to increase the field
on the top of the PMG, ferromagnetic materials are introduced as magnetic conductors
between two NPMs [53].
Figure 6.1 and Tab. 6.1 show the measured results of the levitation forces with the
single-NdFeB PM cylinder (surface magnetic flux density is 0.38 T) over the NdFeB
PMG (surface magnetic flux density is 1.2 T) [24]. Clearly, the levitation forces of the
NdFeB PMG are much higher than those of single-NdFeB PM cylinder.
The NdFeB PMs has magnetic energy product of 40 MOGe, coercivityHcof
979 kA/m, and relative permeability휇of 1.049. The transverse distribution of magnetic
field of a PMG is shown in Fig. 6.49. The PMG is composed of normal PMs and iron
plate. In Fig. 6.49, the magnetic field at the center of the PMG is stronger than that
at any other position, and it decreases rapidly with the increase of the gap from the
surface of the PMG.
Figure 6.50 shows the measured and calculated results of the magnetic field
distribution of the PMG along the transverse and the vertical direction a PMG along
the vertical direction [35, 43]. Figure 6.50b shows the transverse field distribution at
15 mm above PMG surface. The calculated 1 and calculated 2 correspond to the finite
element method and the equivalent current method, respectively. Table 6.11 lists the
measured magnetic flux densities of PMG center along the vertical direction.
Fig. 6.49:Cross-sectional view of the PMG.