6.13 Maglev vehicle using HTS PMs Ë 185Fig. 6.40:Schematic diagram of a hybrid Maglev
vehicle using PMs and HTS bulks [49].that both the levitation forces and guidance forces of the hybrid Maglev vehicle
provided larger levitation forces and stiffness.
The third scheme (Fig. 6.39b) was the implementation plan of the HTS Maglev
vehicle “Century”. It will be discussed in detail in the following sections. This section
describes some of the early schemes.
The guidance forces of HTS bulk superconductors were used in each of the above-
mentioned schemes, because of the important characteristics of HTS bulk supercon-
ductors. All three schemes had an important defect, i.e. the levitation height of these
schemes was limited. Both height and forces of the levitation are crucial for a Maglev
vehicle.
Jia-Su Wang et al. [48] reported the magnetic levitation of HTS bulk above the PM
or the electromagnets.
The electrical magnet can be controlled in sections along a road. Only the
section where the vehicle was located was charged with electricity. This system of
supplying power was analogous to that of a linear synchronous motor (LSM), but
the electrical magnets were powered by direct current. The magnetic flux density
of an electrical magnet with a soft iron core achieves a field of least 1.0 T, which
can generate a large levitation force. Its shortcoming was the need for a complex
guideway and high electrical energy. Figure 6.41 shows a scheme for a Maglev vehicle
system using the levitation between the HTS bulks and the electrical magnets [48].
The HTS bulks bathed in liquid nitrogen generate a high levitation force. The pro-
pulsion system which used a linear induction motor (LIM) is shown in Fig. 6.41.
This system was only suitable for experimental research. For actual use, it should
have a LSM.
6.13 Maglev vehicle using HTS PMs
The rare-earth PMs with a high energy product and a high intrinsic coercive force have
been widely used and have brought great technical and economic benefit. The HTS