Air gap winding for superconducting electrical machinery

Superconductor technology has advanced rapidly in recent years and superconductors may now be applied to the DC windings of rotating electrical machinery. These machines operate with high air gap flux densities and this requires the use of an air gap stator winding, in which stator teeth are not used. The mechanical and electrical requirements of an air gap winding are described. A 5 MVA, 3 ph, 60 Hz, 4160 volt, 3600 RPM S.C. Generator utilizing an air gap winding which has been built and tested is described. The test results are presented for the S.C. Generator with the rotor winding operating at 4°K. Future developments are discussed for the application of S.C. Generators and S.C. Motors to power generation and ship propulsion.