Numerical analysis of a superconducting bearing

High-Tc superconducting bearings are expected as a key technology for flywheel energy storage systems (FWES). However, low bearing stiffness behavior becomes a serious obstacle to realize FWES. We have so far suggested various kinds of bearing construction to improve the bearing stiffness, but the various improvements of superconducting bearings bring complicated magnetic circuit structure, which makes the analysis of the bearings and realization difficult. For this reason, we have been constructing the numerical analysis program using three-dimensional sealer potential method based on the critical state model to proceed with the stiffness improvement study. In this paper, we show the validity of the developed program for the disc-type superconducting bearing, which consists of a superconductor and a permanent magnet. This means that we can estimate the behavior of real size superconducting bearings for FWES.