Suppression of rotor fall for radial-type high-temperature superconducting magnetic bearing

The superconducting flywheel energy storage systems (SFESS) using superconducting magnetic bearings (SMBs) have been studied actively to contribute to electric daily load leveling. In development of SMBs, which are key technology of SFESS, it is one of the important issues to minimize descent of the rotor due to decline with time in levitation force of SMBs. Thus we have evaluated the levitation force of a module of 126 mm diameter class radial SMB in order to study of this subject. We have confirmed the effectiveness of a method using the temperature characteristic of a superconductor (SC) (the supercooling method), a method using the hysteretic characteristic of a SC (the pre-loading method), and a combination of these two methods. Therefore we have confirmed the characteristics and effectiveness of these methods. (C) 2003 Elsevier B.V. All rights reserved.