Comparison of axial flux permanent magnet machines with fractional and integral slot per pole

This paper presents the comparison of axial flux permanent magnet (AFPM) machines with fractional and integral slot per pole in term of torques and losses. The two AFPM machines with 1.5 slots / pole / phase and 2 slots / pole / phase are analyzed using three-dimensional finite element method. The electromagnetic torque, cogging torque and torque ripple of these two machines are compared. Machine losses caused by space harmonics and time harmonics are respectively evaluated. Comparisons of simulated and measured values on prototype machines are also presented to validate the analyses.