Analysis of the Levitation Force of Radial-type High-TC Superconducting Magnetic Bearings using a Halbach Permanent Magnet

Superconducting flywheel energy storage systems using superconducting magnetic bearings have been studied for their feasibility to contribute to daily load leveling. To make the system fit for practical application, the levitation force of radial-type superconducting magnetic bearing must be enhanced. If the magnetic flux leaked outside of the permanent magnet can be induced internally to the furthest possible extent and the magnetic flux acting the superconductor can be increased, it is believed that the levitation force will be enhanced. Therefore, we introduced the idea of applying a Halbach permanent magnet, which produces a strong magnetic field almost totally on one side, to the permanent magnetic assembly. The magnetic field and levitation force in the case where a Halbach permanent magnet is applied were then analyzed. Based on the results of analysis, we have demonstrated that levitation force is enhanced when the above-mentioned Halbach permanent magnet is applied to a radial-type superconducting magnetic bearing.