Suspension-Type of Flywheel Energy Storage System Using High Tc Superconducting Magnetic Bearing (SMB)

In this paper, a new superconducting flywheel energy storage system is proposed, whose concept is different from other systems. The superconducting flywheel energy storage system is composed of a radial-type superconducting magnetic bearing (SMB), an induction motor, and some positioning actuators. The SMB is composed of a superconducting stator and a flywheel rotor. The flywheel rotor is suspended by the superconducting stator, whose one end is fixed to a stable and heavy base. Free-run experiments in the case of the unfixed stator are performed. The natural rotation decay curve, displacement at the upper position of the rotor and displacement at a lower position of the rotor are measured. Moreover, free-run experiments in the case of the fixed stator are performed, and the same dynamic characteristics of the unfixed stator are measured. Especially, impulse responses for the rotor in the case of an unfixed stator are very different from those in the case of a fixed stator. The experimental results discuss some important characteristics of the superconducting flywheel energy storage system, whose rotor is suspended by the superconducting stator.