Investigation of a Biased-Flux Halbach-Configured Permanent Magnet Motor

A novel biased flux permanent machine is proposed in this paper. Regarding the rare earth permanent magnets’ cost and availability, it is necessary to decrease the consumed volume of these materials. The proposed motor specific design concludes to drastically increase the PM torque density rather than the conventional intermodular permanent magnet motor due to lower consumed PM volume. Both motors are investigated in terms of the back-EMF waveform, cogging torque profile, torque profile, and overload capability. Although the proposed motor has a lower PM volume, the novel design of the stator tooth causes to higher air gap flux density which leads to the same amplitude of back-EMF and average torque for both motors. The HBFPM stator module design led to increasing the 1,6, and 12 cogging torque harmonic components. These increased harmonic components increase the torque ripple. Also, the segmented modular stator shape causes to increase in the flux leakage and concludes to decrease the power factor by 3%.