Analysis of the Amount of Flux Variation on the HTS Surface by the Oscillation of HTS Magnetic Bearing Rotor

Magnetic bearing is used in flywheel energy storage system and can address energy loss at contact points in rotating because a rotor can be supported without contact points. However, in order to keep a rotor levitating, a control system is required. The high-temperature superconductor (HTS) magnetic bearing levitates the rotor by pinning force without a control system and of a rotor including permanent magnets and a HTS. The vertical oscillation of the rotor is suppressed because the flux is interlinked to the outside of the HTS. Therefore, the rotor oscillates in the horizontal direction in rotating. This oscillation generates the flux variation on the HTS surface and it decreases the number of revolutions. This article proposes an analysis of flux variation on the HTS surface by the oscillation of HTS magnetic bearing rotor. The effect of the oscillation of the rotor on the number of revolutions is shown by the analysis of the flux variation of the HTS. In the analysis results, the amount of flux variation increased rapidly because the rotor increases the oscillation. The flux variation causes a decrease the in number of revolutions and the small oscillations cause flux variation on the HTS surface. However, the decrease in the number of revolutions is small because the amount of the flux variation is small.