Assembly and Qualification of a Slotless Stator Assembly for a MW-Class Permanent Magnet Synchronous Machine

This paper discusses the manufacturing process and qualification procedures of a slotless stator for a 1-MW high-speed permanent magnet synchronous machine. The motor, targeted to reach 13 kW/kg, is assembled with form-wound air-core armature windings which utilize litz wire as the conductor. A prototype is being developed and a full-power test will be done in the near future. The insulation, mechanical and thermal qualification test procedures of the stator are discussed in detail. Results showed that the manufacturing process and tolerances significantly affect the machine performance. Various assembly challenges of this slotless stator and their impacts on performance targets are illustrated.