A measurement of rotation loss characteristics of high-Tc superconducting magnetic bearings and active magnetic bearings

As the demand for electric power has been increasing steadily, the introduction of a flywheel energy storage system (FESS) using a superconducting magnetic bearing (SMB) is needed to level daily load as much as possible (daily load-leveling). We have studied rotation loss characteristics of SMBs with high Tc superconductors (YBCO) and permanent magnets (PM) for supporting a flywheel in FESS. We have designed and manufactured a testing machine for measuring rotation loss characteristics of SMBs. The rotor is suspended by two sets of radial active magnetic bearings (RaAMBs), a set of axial active magnetic bearings (AxAMB) and a set of SMB. Then, we obtained rotation loss characteristics of the rotor levitated by RaAMBs, AxAMB and SMB on this testing machine.