Development and test of world's first industrial high temperature superconducting (HTS) power cable

Southwire Company has installed the world's first industrial high-temperature superconducting cable system to power three of its main manufacturing plants. The cable consists of three single-phase, 30 m long cables designed to carry 1250 A at 12.4 kV. The cable is cooled by a liquid nitrogen (LN) system that can supply LN at sub-cooled temperatures down to 72 K and at pressures up to 15 atmospheres. The design of the 30 m cables is based upon two 5 m cable prototypes, which were tested at a specially developed facility at ORNL. In addition to critical current and AC loss measurements, simulated fault-current tests were performed at ORNL on the 5 m cables. Cable terminations were designed to allow smooth transition from the cryogenic temperature and pressure environment of the HTS cable to ambient temperature and pressure for copper cables. A dielectric tape material, Cryoflex/sup TM/ was also developed for use at cryogenic temperatures.