Design and construction of LN(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(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(RMS). This paper describes the design rationale, the construction process and the highlights of the test results