Electromagnetic and Mechanical design of a Fractional-slot-windings Axial-flux PM synchronous machine with Soft Magnetic Compound Stator

Despite their favorable aspect ratio, axial flux PM synchronous machines can compete with traditional radial flux machines in terms of torque and power density only if the number of pole-pairs is sufficiently high and the ratio axial length/outer diameter is low. Since axial flux PM synchronous machines have an inner stator hole, the number of stator slots is bounded, therefore in order to increase the number of poles per slots fractional slot windings arrangements can be utilized. Frequently, this procedure results into a more compact winding design, resulting in lower copper losses due to shorter end connections. This paper deals with the electromagnetic and mechanical design of a fractional windings axial flux PM synchronous machine with soft magnetic composite featuring low eddy-currents losses at high frequency and self-cooling air channel system. The whole design procedure was done using finite element analysis and multiphysics tools