Stator Design for a 1000 kW HTSC Motor With Air-gap Winding

An air-gap winding (air-core) stator for a 1000 kW high temperature superconducting synchronous motor is designed by the Global R&D Center, TECO-Westinghouse Motor Company. This motor uses HTSC wire in the rotor field coils and Litz-wire cable in the stator coils. The rotor's cryogenic system cools the superconducting field coils to low temperature. Stator winding and back iron both are in a `warm stator' state. The stator coil chooses Roebel type Litz-wire with to eliminate the harmonics, cogging torque caused by slot opening, and to reduce vibration/noise. A quick algorithm is developed to design the stator. Electromagnetic and mechanical analyses are based on 3D FEA and thermal analysis is based on 2D FEA. Manufacture techniques for Litz wires are being developed, e.g., coil winding, crimping, testing and installation. The stator coil is in the manufacturing stage currently, and the complete machine will be tested by the end of 2010.