Flux-switching PM brushless machines with alternative stator and rotor pole combinations

New flux-switching permanent magnet (FSPM) brushless machine topologies with different stator and rotor pole combinations (Ns/Nr) are developed, with potentially reduced stator and rotor pole numbers without introducing the unbalanced magnetic force. The relative merits of FSPM and flux reversal permanent magnet (FRPM) brushless machines are evaluated. The electromagnetic performance, including back-emf, static torque, cogging torque, stator and rotor iron losses and magnet eddy current loss, and unbalanced magnetic force, etc. of new FSPM machines having Ns/Nr =12/16 and 6/8 is also compared with that of existing FSPM machines having Ns/Nr =12/10 and 6/5 by finite element analyses and experiments.