3-D–2-D Dynamic Magnetic Modeling of an Axial Flux Permanent Magnet Motor With Soft Magnetic Composites for Hybrid Electric Vehicles

Axial flux permanent magnet (AFPM) motors might be an efficient traction solution for hybrid and full electric vehicles. This technology makes the use of soft magnetic composites (SMC) attractive for both manufacturing and performance reasons. Eddy currents in the iron can provide a natural transient damper and/or flux weakener and the iron losses might be compensated by the high torque density of axial structures. The main problematics of magnetic modeling in AFPM motors made with bulk SMC teeth and poles are leakage at the ends, slots effects and finally damping and losses. This paper deals with the material and geometry-dependent magnetic modeling of such a 3-D machine for design purpose considering a maximum a priori effect. Section I begins with the context, state-of-the-art and the geometrical modeling compatible with axial structures. In Section II, the magnetic equivalent circuit (MEC) of the machine is built, then the quasi-static electromagnetic behavior is computed, with time and space harmonics in a steady state. Section III is dedicated to an investigation of magnetic damping and losses, inside lumped parameters, either in a steady state or in a transient state. In Section IV, provided calculations are compared with each other, to the finite element method and to measurements.