Development of large-current-carrying superconducting cable for AC use

Large-current-carrying superconducting cable with sub-micrometer NbTi filaments has been developed for the application of AC power devices such as superconducting rotating machines, SMES and fault current limiters. The quench current and the loss under AC operation have been measured. The results show that the superconducting cable has AC transport current of at least 2000 A/sub rms/ at 50 Hz in a 5T DC background magnetic field. The AC losses are measured to be 1.5/spl times/10/sup 3/ W/m/sup 3/ with 1000 A/sub rms/ transport current at 50 Hz, which are remarkably low.