Japan's first operation of high-temperature superconducting cable systems in live grids (high-temperature superconducting cable demonstration project)

Sumitomo Electric Industries, Ltd. has taken part in the high-temperature superconducting (HTS) cable demonstration project, began in 2007, to verify the reliability and operational stability of HTS cable systems in actual power grids. The company has developed 66-kV-, 200-MVA-class HTS cables, terminations and joints, and built a 30-meter cable system using them to conduct verification tests before the demonstration in Tokyo Electric Power Company's Asahi Substation in Yokohama. At present, Phase I of the rating validation test has been completed with favorable results, verifying the soundness of the 30-m cable system. A 30-day long-term operation test was also completed successfully. Going forward, Sumitomo Electric will conduct heat cycle and marginal performance tests with the system in Phase II and Phase III.