Design and construction of LN/sub 2/-cooled prototype superconducting transmission cable

The Southwire Company (USA) has initiated an R&D project to develop superconducting underground power transmission cables using newly developed high-temperature superconductors (HTS). In collaboration with Oak Ridge National Laboratory, two 500 A and one 2000 A prototype cables have been designed, constructed and tested. The cables were wound with Bi-2223/Ag HTS tapes acquired from Intermagnetics General Corporation and tested with both DC and AC currents in liquid nitrogen (LN/sub 2/). Critical currents of 900 A DC or better were achieved for the first two cables. The third cable was tested to an AC current over 2200 A/sub RMS/. This paper describes the design rationale, the construction process and the highlights of the test results.