288 Ë 8 New progress of HTS Maglev vehicle
Fig. 8.29:Guidance forces vs. lateral displacement on the different trapped-field conditions.
magnetization field. As shown in the upper right inset of Fig. 8.29, the guidance forces
saturated from the 0.349-T trapped field because of the trapped flux saturation in the
YBCO sample.
Combined with the levitation force curves in Fig. 8.28, both the levitation and
guidance forces on the 0.071-T trapped-field condition could almost achieve 20.6 N
at a 10-mm levitation height and 1.3 N at a−10-mm lateral displacement on the
conventional 30-mm FCH condition. Moreover, larger levitation and guidance forces
can also be accomplished at other trapped-field conditions.
It is very interesting to find that the HTS bulk magnet with the 0.349-T trapped
field achieved a 9.8-N maximum guidance force which was more than 7 times that of
a conventional FCM condition for the 30-mm FCH. These experimental data further
confirmed that the HTS bulk magnet can be of benefit to some HTS Maglev curve
applications which needed the larger guidance forces and stiffness.
Furthermore, it can be a feasible and efficient way to improve the HTS Maglev
performance by introducing the HTS bulk magnet, but without changing the original
design considerations because the HTS bulk magnet works at the same temperature
condition of the HTSC with the conventional FCM. In fact, because the trapped flux
density of the HTS bulk magnet can be easily artificially controlled according to
the fixed magnetization ratio of the superconductor material, the HTS bulk magnet
will be easily magnetized to the required magnetic flux density, and then the requi-
red levitation performance and stability in an applied magnetic field according to
practical design parameters.
8.3.2.2Zero field-cooling re-magnetization
ZFC and FC are two popular magnetic activation ways for HTS Maglev vehicle appli-
cation. The HTS bulks with ZFC processes can have a bigger levitation forces (load