Abstract：To effectively simplify the system structure and improve the power density and efficiency, the design of a motor/generator was proposed for flywheel energy storage system with outer-rotor and coreless-stator-type bearingless permanent magnet motor with Halbach array. The working principle of the outer-rotor bearingless permanent magnet motor was described. The structure and the performance of Halbach array permanent magnet rotor were analyzed. Air gap magnetic field, back-EMF, suspension force, unilateral magnetic pull force and electromagnetic torque of the motor were calculated and analyzed by finite element method. The rotor eddy current loss of the bearingless permanent magnet motor was analyzed by transient finite element method coupled with external circuit. The simulation results show that compared with the traditional bearingless motor, the coreless-stator bearingless permanent magnet motor with Halbach array has better performance of air gap magnetic field, back-EMF, suspension force, unilateral magnetic pull force, electromagnetic torque and rotor eddy current loss, which is suitable for the application in flywheel energy storage system.
2016, Vol. 37 
