Analysis of an armature reaction effect in the case of a special spoke type BLDC motor using a ferrite permanent-magnet

In this paper, we propose a design of a special spoke-type brushless direct current (BLDC) motor using a ferrite permanent magnet and an analysis of armature reaction effect for the special spoke-type motor. Firstly, we design the special spoke-type BLDC motor, considering its cogging torque to be improved, and adjust an angle between the permanent magnets. By changing the angle, it is helpful to concentrate the fluxes of the permanent magnets, thereby increasing the air-gap flux density. Secondly, an armature reaction effect in this special case motor is analyzed because the spoke-type motor is significantly affected by this effect as compared with surfaced permanent magnet type BLDC motor. Therefore, we analyze the effect of the armature reaction according to the mechanical load and the input current. The output performance of the special spoke-type motor and the armature reaction effect are verified through a finite element analysis and an experiment.