VIBRATION SUPPRESSION OF A DISK-SHAPED SUPERCONDUCTOR WITH PD CONTROL

In order to investigate superconducting magnetic bearings (SMBs) using repulsion forces between superconductors and electromagnets, an exper imental setup for a thrust SMB able to move in one direction has been made. The experimental setup is composed of a high Tc superconductor, permanent magnets, electromagnets and a Hall sensor. The superconducto r used in this paper is supported by the permanent magnets in the radi al direction. The vibration of the superconductor is suppressed by an analog PD (proportional and derivative) controller. From the experimen ts, it is found that suppressing the vibration is well performed by th e PD controller. Also, it is found that the controller needs more resi stance against disturbance caused by the pinning effect. (C) 1997 Else vier Science Ltd.