Novel dual stator switched flux hybrid magnet memory machines

In this paper, novel dual stator switched flux hybrid magnet machines (DS-SF-HMMM) are proposed. Two sets of armature winding are employed so as to improve the space utilization ratio and torque density. Whereas, two kinds of permanent magnets (PMs), i.e., NdFeB and low coercive force (LCF) magnets are placed on either a single stator or two separate stators. The proposed machines can provide the merits of high torque density in dual stator machines, and excellent field variability in low coercive force (LCF) PMs. The topology evolution and operating principle of the DS-SF-HMMMs are introduced and highlighted. In addition, aiming at the drawbacks of original design, two alternate spoke-type designs are presented increase the copper area with better manufacturability. The power splitting ratio between two stators and stator/rotor pole combination are analytically optimized in order to realize torque maximization. The electromagnetic characteristics of the improved and original designs are evaluated and compared by the finite-element (FE) method. Finally, two prototypes are manufactured and tested to verify the FE analyses.