Development and testing of HTS cables and terminations at ORNL

The Oak Ridge National Laboratory (ORNL) and the Southwire Company have used the ORNL 5 m cable test facility to develop high-temperature superconducting (HTS) cables and terminations to support the first industrial demonstration of an HTS cable at the Southwire manufacturing complex. Two 5 m, cold dielectric cables have been tested for direct current (DC) voltage, alternating current (AC) losses, AC withstand at 18 kV, thermal-hydraulic performance, heat load, and long-term operation at rated voltage (7.2 kV) and current (1250 A). Two separate termination concepts, one operating at 10/sup -4/-10/sup -5/ mbar vacuum and the other operating with pressurized nitrogen gas at <10 bar, have been developed and tested with the 5-m cables. A 5-m cable has been removed from the facility and bent in a test rig to simulate transport in a spool. A testing program for a third 5-m cable with a splice is in progress. The test program at ORNL has validated the basic design of the cables and terminations and indicated areas for further R&D to optimize this technology for electric utility applications.