125 HP HTS motor field winding development

Superconducting motors offer improved efficiency as well as reduced size and weight. A four pole coil configuration has been developed which provides in excess of 56000 ampere turns per pole for a 125 HP motor. The winding achieves an operating current density (Je) in excess of 6300 amp/cm/sup 2/ at the 27 K operating temperature. The superconductor used is multifilamentary Bi-2223 in a silver matrix. The design, development and performance of the air-core synchronous motor coils are described with emphasis on the static test results and implications for large motor development.