A flux-modulated low-speed motor with an improved structure and its performance analysis using finite-element method

Low-speed flux-modulated (FM) motor, which violates the conventional design rule and has different number of pole pairs in the stator and rotor, is examined. In the original FM motor, the magnetic flux is modulated using special iron segments in the air gaps. It has the merit of having high power density at low speed. In this paper an improved structure of the FM motor which has only one air gap between the stator and the rotor is presented. The performance of the proposed FM motor is compared with that of the original FM motor, which has two airgaps, using magnetic field finite-element method (FEM). It shows that the output torque of the new motor can be larger than that of the original FM motor by about 26%.