Testing of the dependence of the number of layers on the performance of a one-meter HTS transmission cable section

A one-meter long prototype transmission cable was constructed by Southwire Company consisting of four layers of helically wound Bi-2223/Ag HTS tapes. Measurements were made at Oak Ridge National Laboratory of the DC V-I characteristics and AC loss of the as received cable and after sequentially stripping the outermost layer so that a series of measurements for four-, three-, two- and one-layer cables were completed. The differences in the cable performance could then be compared with existing theories. In its initial four-layer configuration the measured critical current was over 1500 A. After the removal of the outermost layer to form a three-layer cable, the critical current dropped to 881 A. The performance degradation that was measured is not in direct proportion to the number of tapes in the cable. The DC V-I characteristic curve, critical current and AC losses are reported for each configuration.