A Novel Proposal to Improve Reliability of Spoke-Type BLDC Motor Using Ferrite Permanent Magnet

This paper proposes a novel proposal to improve reliability of a spoke-type brushless direct current (BLDC) motor using ferrite permanent magnets (Fe-PMs) through a new design. First, the design process for a neodymium permanent magnet (Nd-PM) free spoke-type BLDC motor without assistant permanent magnets (PMs) is presented. The proposed motor is designed by taking into account the demagnetization phenomenon. Second, the effect of the armature reaction on the PMs is analyzed by using the finite element method (FEM) in order to evaluate the robustness of the proposed motor with Fe-PM. In addition, another proposal to avoid the demagnetization phenomenon is suggested. Finally, a prototype motor is manufactured based on the proposed motor. The output characteristics of prototype motor and the demagnetization phenomenon are verified through an experiment.