Field-Winding Claw-Pole Type Motor Characteristics Analysis Using Additional Ferrite Magnets

Abstract

The magnetic flux density of a rotor core is increased on the basis of the B-H characteristics of the core when the field current of a field-winding claw-pole type motor (FWCPM) is increased. However, owing to the saturation of the rotor core caused by the increase in magnetic flux density, the magnitude of the electromotive force relative to the field current increase in a nonlinear direction. Therefore, to improve the performance of the FWCPM, it is necessary to reduce the leakage flux and rearrange the source of the rotor in order to supply additional magnetic flux. In this paper, three types of ferrite assisted field-winding claw-pole type motors (FAF-WCPM) are proposed to improve the nonlinearity and performance of the FWCPM field current. The magnets applied to the FAFWCPM are located between the claws, at the front of the claws, and at the tops and bottoms of the claws. Further, to ensure analytical accuracy, the amount of magnets used in the motor is equally limited. Finally, the magnitude of the electromotive force under a no-load condition and the average torque under the load condition are studied through three-dimensional finite element analysis.