HTS-MAGNET LEVITATION BEARING FOR FLYWHEEL ENERGY-STORAGE

Advances in high temperature superconducting matelials have brought ab out the possibility of design of totally passive bearings with low fri ction loss. Bearings with such advantages are useful for kinetic energ y storage designs. We have designed and constructed a flywheel prototy pe using a concept of a hybrid superconducting magnetic bearing (HSMB) . The HSMB design uses magnetic forces from permanent magnets for levi tation and high temperature superconductors (HTS) in between the magne ts for stabilization. The bearings levitate a rotor of 19 kg and the f lywheel can currently rotate up to 6,000 RPM. The result from the rece nt spin-down tests indicates an average frictional energy loss < 2% pe r hour. Most of the friction is due to the condition of an imperfect s ystem assembly alignment and an unbalanced rotor. Improvement of the s ystem is ongoing. This paper summarizes our research activity based on some of the results reported recently at several conferences [1,2,3].