Improving the dynamics of two types of flywheel energy storage systems with SMBs

This paper describes two types of energy storage systems (I and II) with a flywheel rotor supported by superconducting magnetic bearings (SMBs). Both systems I and II are composed of a rotor and superconducting magnetic bearings (SMBs) at both ends of the rotor. The rotors of systems I and II are driven by using an air turbine and a brushless motor, respectively. The superconductors of the systems I and II are field-cooled by using liquid nitrogen and a cryogenic refrigerator, respectively. In this paper, a new method for improving the dynamics of the passive type SMBs for two types of flywheel energy storage systems is discussed. The method is performed by changing relative displacements between the SMBs and the rotor PMs after field-cooling process.