We report present status of NEDO project on "Superconducting bearing technologies for flywheel energy storage systems". We fabricated a superconducting magnetic bearing module consisting of a stator of resin impregnated YBaCuO bulks and a rotor of NdFeB permanent magnet circuits. We obtained levitation force density of 8 N/cm2 at 81 K and rotation loss per levitation force of 3 mW/N at 77 K. We confirmed that both pre-loading and excess cooling methods are effective for suppressing gradual fall of rotor due to flux creep. We designed a 10 kWh class flywheel energy storage test system and investigated feasibility of active magnetic bearings for controlling rotation axis vibration under high speed rotation of the flywheel.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering