Effects of Longitudinal Variations in Critical Current and n-Value of Individual Tapes on the Performance of Superconducting Cables

This paper presents results and analysis of simulations on critical current of superconducting cable affected by longitudinal variations of superconducting properties typically observed in commercial second generation high temperature superconducting (2G HTS) tapes. Monte Carlo simulations coupled with mathematical models of superconducting cables made from multiple tapes were used to assess potential risks in cable operations that are caused by longitudinal variations in I_c and n-value of the conductor used to fabricate long cables. It was observed that the apparent critical current derived from measurements of long tape sections and cables mask the sections with lower critical current. It is shown that the variations in I_c reduce the designed capacity of the cables and increase the chances of catastrophic damage when a cable is operated close to its critical current.