Investigation of an Axial-Gap Electromagnet-Assisted Ferrite Magnet Motor

Abstract

The electromagnet-assisted ferrite magnet motor (EMaFM) is a new type of rare-earth-free motor in which the torque due to a ferrite magnet motor is assisted by the variable magnetic force of an electromagnet motor. In this paper, an axial-gap EMaFM (AG-EMaFM), which combines a ferrite magnet motor with an electromagnet motor in the axial direction, is newly proposed. Its topology and operating principle are also presented. The proposed AG-EMaFM makes it easy to increase the conductor areas of the windings and can offer satisfactory torque density. To verify this concept, the electromagnetic performance of the proposed AG-EMaFM is investigated using a three-dimensional finite element analysis and compared with a radial-gap EMaFM of the same size.