Development of (RE)BCO cables for HTS power transmission lines

High-temperature superconducting (HTS) power cables transmit bulk power with lower loss than conventional cables. Moreover, HTS cables are expected to be constructed as a new underground cable in urban areas at lower cost compared to a high voltage XLPE cable. To put promising HTS cables to practical use, we need (RE)BCO tapes with long length, high critical current, and low cost. Recently many organizations have improved the performance of the (RE)BCO tapes, such as YBCO tapes, or other coated conductor tapes that are made with a variety of different processes. We have fabricated the conductors for the HTS power cable that was constructed of different kinds of (RE)BCO tapes and measured the I_c and AC losses. We achieved significantly low AC loss of 0.1 W/m at 1 kA in the HTS conductor using narrow slit tapes that were cut by laser. Moreover, a 20 m long HTS power cable model and a cable intermediate joint were developed. Short circuit current tests were conducted on the cable system that consisted of two 10 m cables, a cable joint, and two terminations. The cables and the joint withstood the short circuit current of 31.5 kA for 2 s without damage.