A Novel Double-Sided Offset Stator Axial-Flux Permanent Magnet Motor for Electric Vehicles

Abstract

Axial-flux permanent magnet (AFPM) motors have been attracting great interest due to their key advantages of high-torque density and compact structure. Concentrated windings are commonly used for AFPM motors since they significantly reduce the radial length of the end windings. This paper proposes a novel double-sided stator single-rotor motor topology where one stator is offset by π radians. This arrangement can cancel significant space harmonics produced by the concentrated winding and reduce the core and permanent magnet losses. Analytical analysis and finite element analysis (FEA) are used to verify the principle and validate the topology. The simulation results demonstrate that this proposed double-sided offset stator motor can reduce the core loss and permanent magnet loss significantly at base speed compared with the conventional double-sided stator single-rotor motor. In addition, the magnetic core saturation and induced voltage for the double-sided offset stator motor are significantly reduced.