With the development of high temperature superconducting (HTS) materials, Southwire initiated an R&D project in 1995, to develop a superconducting underground transmission cable. In collaboration with Oak Ridge National Laboratory (ORNL), nine 1-m long, prototype HTS transmission cables were designed, built, and tested. Based upon the test results of 1-m cables, a decision was made by SW management to construct a 3-phase 30-m cable which will be installed between two overhead power lines bringing power to Southwire Company. The HTS cable will be designed to carry 1250-A at 12.5 kV to match with the overhead power supply. A 5-m cable of cryogenics design has been constructed to test the design of our 30-m cable. A suitable dielectric has been developed and tested to withstand high voltage at liquid nitrogen temperature. A versatile test facility has been designed and assembled at ORNL for the testing of 5-m cable. Design modifications for 30-m cables will be made based upon the test results of 5-m cable, In this paper, the test results of 1-m cables, 5-m cable and installation plans for 30-m cable will be discussed.
