Design of a Compact Stator Winding in an Axial-Flux Permanent Magnet Machine for Aerospace Applications

The weight and volume of electric drive systems are of primary concern in aerospace applications. Here, a high power density axial-flux permanent magnet machine is developed. A compact stator winding with rectangular wire is proposed. The stator coils are connected along the machine inner diameter (ID). The ID connections help to reduce the machine weight and volume and meet the application targets. A detailed winding design procedure is presented considering manufacturing constraints. An electrostatic analysis is also performed to define the wire insulation thickness and the minimum spacing between conductors to assure the insulation system is free of partial discharges. Additional half turns are added to three coils of the winding to place the three-phase terminals at the machine outer diameter (OD). The resultant electromagnetic impact of these three coils is assessed.