A concentrated flux type ferrite magnet motor with improved torque density

摘要

Motors using rare earth elements have high efficiency and torque density, but they have the drawback of a high price. Thus, this paper proposes the use of ferrite instead of rare earth elements to increase the torque density and decrease the material cost. This paper discusses models with structures that increase the flux per pole and saliency ratio. Using the finite element method, the models are compared in terms of the no-load back-electromotive force (EMF) and back-EMF per permanent magnet used. A comparison is made of the values for the no-load back-EMF and back-EMF per permanent magnet used in motors with the proposed structure and a general overhang structure. Thus, this paper verifies whether a motor using ferrite with the proposed structure can replace a motor using rare earth elements.