부산대학교 도서관

This paper proposes a quasi-cylindrical function contour rotor to reduce the windage loss and torque ripple (cogging torque) of stator-permanent magnet flux-switching (SPM-FS) machines, where the rotor tooth top contour conforms to the function y = ax 2 , and the overall appearance of the rotor is quasi-cylindrical. Firstly, three conventional rotors and one new rotor are introduced, and the difference in the modulation process between the four rotors are investigated based on the general air-gap field modulation theory (AFMT). Then, the advantages of the proposed rotor are verified from the perspectives of time-averaged torque amount reduction and torque ripple. It is found that the function contour can reduce the torque ripple (cogging torque) by about 76∼90%, while the quasi-cylindrical appearance can reduce the windage loss by about 66% at 10,000rpm. Surprisingly, the proposed rotor maintains a high convective heat transfer capacity of the air within the air-gap, which is beneficial for the machine's heat dissipation. Von Mises stress and deformation analysis verify the mechanical reliability, and manufacturing process of proposed new rotor is introduced. Finally, experiments are carried out to verify the validity of the rotor.