Simple Pseudo-IPM Rotor Design of Axial Flux Machine for Wide Speed Range

This study proposes a simple segmented pseudo-interior permanent magnet (p-IPM) rotor of an axial flux machine (AFM) to extend the constant output range at higher speeds with reluctance torque production using field weakening control. The proposed rotor includes rectangular laminated electro-magnetic cores between the magnets. The p-IPMAFM investigated in this study has a double-stator/single-rotor configuration with distributed winding. The motor performances with different slot/pole combinations of 36s/6p, 36s/8p, and 12s/8p were calculated using the finite element method. It is concluded that the short-pitch distributed winding of the 36s/8p configuration has a higher average torque and reduced torque ripple. A test machine was fabricated and tested, and the maximum efficiency was 93.0% with a torque of 4.5 Nm at 5,000 rpm.