5.6 HTS Maglev dynamic measurement system Ë 143Fig. 5.34:Vibration measuring results of the body frame and the clamp device of the liquid nitrogen
vessel (perpendicular and horizontal direction) at rotation speeds of 50 rpm, 100 rpm, 150 rpm,
200 rpm, 300 rpm, and 400 rpm. Left (right) figure shows the measuring results without (with) the
liquid nitrogen vessel on the clamp device [12].
vessel on the clamp device. The right figure shows results with the liquid nitrogen
vessel attached. After the YBCO superconductors in the vessel were cooled in the zero
field, vibration properties were measured at the levitation gap of 20 mm and lateral
displacement of 0 mm. Experimental results showed that the vibration of the body
frame increases quickly with increased of rotation speed, and the vibration of the
clamp device with or without the liquid nitrogen vessel also increased slowly with
increased rotation speed. This indicated that the measuring seat had the function of
vibration isolation. The vibration of the clamp device with the liquid nitrogen vessel
satisfied measurement requirements.
5.6.4Measurements of HTS Maglev properties
The main distinction between the SCML-03 [12] and previous HTS Maglev measu-
rement systems [2, 11] is measurement of the Maglev performance under operating
conditions, with the SCML-03, both levitation forces and guidance forces are measu-
red experimentally at different velocities.
The experimental results of the levitation forces and the guidance forces of YBCO
bulk measured with the SCML-03 are shown in Figs. 5.35 and 5.36, respectively, in the
static state. The levitation forces of YBCO bulk were measured in zero field cooling
(ZFC), and the guidance forces of YBCO bulk were measured at a 15 mm field cooling
height above the circular PMG. Those measurement results verify that the SCML-03
can accurately measure the levitation and the guidance forces in the moving state.
In order to confirm the measurement results for the levitation forces and the
guidance forces of YBCO bulks, the changes of the measurement results with different