8.3 Methods to improve Maglev performances Ë 301Fig. 8.41:Magnetic field distribution of the Halbach PMG. (a) The profile at a gap of 15 mm. (b) When
a 1-mm-thick iron plate is introduced to the bulk surface above the middle of the PMG.Bnis the
vertical component andBtis the horizontal component of the magnetic field.
Fig. 8.42:Levitation (a) and guidance force (b) curves of the bulk sample measured above the
middle of the PMG with and without introduced iron plates.
ferromagnetic material on the bulk levitation unit can be used for cases where a
large guidance force was needed. At the same time, the experimental results also
confirmed the conclusion that it was very difficult to improve the levitation forces
(load capability) and guidance forces (stability) simultaneously with the HTS bulks
and applied magnetic fields in practice. Usually, we improve one of them according to
actual requirements. For instance, in the case of a curved-route running line, a large
guidance force was required to overcome the centrifugal force. A new HTS Maglev
design making use of the results of this chapter is schematically as shown in Fig. 8.43.
With the reasonable choice of thec-axis direction of the HTS bulk (see Section 8.3.4)
and introduction of iron plates, the guidance performance (stability) can be enhanced
greatly compared with the common levitation system, so that it is able to meet some
special requirements like curved-route cases.