High Temperature Superconducting Magnetic Levitation

6.13 Maglev vehicle using HTS PMs Ë 187

Fig. 6.43:Scheme B for Maglev vehicle systems using

the HTS PMs [48]. (1) Coil of LSM. (2) HTS PMs. (3)

Control coils. (4) Slide for landing. (5) Vessel of liquid

nitrogen. (6) Road pier.

Fig. 6.44:Arrangement scheme of HTS PMs [48].

(1) HTS PMs. (2) Control coils. (3) Flux line.

PMs are arranged in a row (see Fig. 6.44). This scheme cannot be realized until a stable,
high field is reached in the HTS PM. The current EMS system using normal conductors
is called the Transrapid-07 (TR-07) in Germany. One of the principal drawbacks of the
TR-07 EMS system is the small gap (10 mm) between the vehicle and the guideway
rail. The Japanese have developed the electrodynamic suspension (EDS) system using
LTS magnets at 4.2 K. The EDS system uses a large gap (100 mm), but the operating
temperature is very low, and it is not a static suspension. The all-superconducting
scheme with HTS PMs possesses a great number of the merits [48]:

1. It is a new EMS system. In other words, not only it is a static suspension, but also
   it has a larger gap between the vehicle and the guideway rail.


2. The speed can reach over 500 km/h.


3. The restriction for the tolerance in the guideway rail is lower.


4. Both the production cost and the operating cost are lower because the low-
   temperature system is cooled with liquid nitrogen.


5. The energy consumption is lower.


6. The environmental pollution is very small.

The above advantages predict success using the HTS PMs for the Maglev vehicle
systems. Unfortunately, the trapped field is limited by the mechanical tensile strength
of the HTS YBCO superconductors, and the stability of the trapped field is lower. In
addition, both the magnetic circuit and the exciting mode are not suitable for practical
application. Therefore, a model of a hybrid Maglev transportation system using HTS
PMs is presented.