2004 年 39 巻 12 号 p. 638-644
Radial-type superconducting magnetic bearings (SMB) have been developed for a 10kWh-class flywheel energy storage system. The bearings consist of an inner-cylindrical stator comprised of YBCO bulk superconductors and an outer-rotor of permanent magnets. The rotor is suspended without contact via the pinning forces of the bulk superconductors, which are arranged such that the c-axis of each bulk is aligned parallel to the radial direction of the cylinder. After the whole system was completed, various tests focusing on both its static and dynamic behaviors were carried out to confirm that the SMB has sufficient performance for 10kWh-class flywheel systems. In this paper, we describe the implementation of the stator part and report the SMB test results; namely, that the rotor was successfully suspended up to 7,500 rpm. Thus, we succeeded in an energy storage of 2.24 kWh.