Strain properties of transposed segment conductors for a transmission cable

In order to realize the superconducting cable composed of YBCO tapes, we investigated the optimal design for the cabling parameters, crossed pitch length, tape dimension for YBCO and former diameter, etc., in considering the manufacturing process. In the transposed segment, the repulsive force was applied to the crossed pitch tape, and in the case of the segment with a short crossed pitch length, the crossed pitch tape arched, which we called arching phenomena. However, in winding the transposed segment on the former by a few spiral pitch, arching phenomena did not occur even if crossed pitch length was so short that superconducting property of YBCO tape was deteriorated. In winding process of the transposed segment, a slide of constituent tapes occurred in longitudinal direction and it resulted in slack of the constituent tape. As a result, it became clear that the slack strain could be adjusted in order to avoid deterioration of superconducting property of YBCO tape. In cabling process, transverse and longitudinal bending strains were imposed on the tapes in the transposed segment. Consequently, it was found that transverse bending strain can be calculated with the cabling parameters, i.e. former diameter, spiral pitch and tape thickness, and it seems that longitudinal bending strain can also be calculated as well as transverse bending strain. From these results, we obtained important information to realize the superconducting cable composed of YBCO tapes