160 Ë 6 First manned HTS Maglev vehicle in the world
PM guideway. All the bulk samples were fabricated by IFW, Dresden, Germany [28].
Each trisected part corresponds to one growth domain with one seeding crystal. They
were stacked up as one bulk array (90 mm length, 35 mm width, and 15 mm thickness).
Moreover, there was a piece of MSMG bulk with the dimension (90× 36 ×15 mm).
The levitation forces were measured with the HTS Maglev measurement system (see
Section 5.3).
The levitation force of the MSMG bulk and the stacked array in parallel (Fig. 6.8)
and perpendicular (Fig. 6.9) mode were compared. In the parallel mode, the hysteresis
loss of the MSMG bulk was clearer than that of the stacked array in Fig. 6.8, and the
weak-link grain boundaries gave rise to hysteresis behavior. However, their maximum
levitation forces were slightly different. The difference between them was 7.0 N with the
percentage of 4.68%. However, the difference rose up to 36.1 N with the percentage of
21.40% in the perpendicular mode, but their maximum forces dropped to 204.8 and
168.7 N, respectively.
6.4 Levitation stiffness [29]
Levitation force and stiffness of HTS bulk over a PM guideway are key parameters
which are equally important. The levitation stiffness directly represents the change of
Fig. 6.8:Levitation forces of the MSMG bulk
and the stacked array consisting of TSMS bulk
S01, S02, and S03 in the parallel mode [27].Fig. 6.9:Levitation forces of the MSMG bulk
and the stacked array consisting of TSMS
bulk S01, S02, and S03 in perpendicular
mode [27].