Recent development of an HTS power cable using YBCO tapes

Abstract

Overcurrent characteristics and reduction of AC loss are essential for high temperature superconducting (HTS) cable in a real grid. AC loss in an HTS conductor using YBCO could be potentially small but protection for overcurrent was needed.A 0.1mm thick copper tape soldered to the YBCO tape was effective as protection from overcurrent and did not affect the increase in AC loss. The 2m HTS conductor with Cu strands of 250mm2 and YBCO tapes with copper was fabricated. This conductor could withstand overcurrent of 31.5kA for 2s.To reduce AC loss, 10mm wide YBCO tapes were divided into five strips using YAG laser. Using narrower strips and decreasing the space between the strips were effective in reducing AC loss. In consideration of this configuration, a three-layer conductor was fabricated, and AC loss of 0.054W/m at 1kArms was achieved even though it had a small outer diameter of 19.6mm.