Effect of Tape's <inline-formula> <tex-math notation="LaTeX">$I_{\rm c}$</tex-math> </inline-formula> Inhomogeneity and Strand Misalignment on the Transport Capacity of Roebel Cables

Abstract

In calculations for predicting the performance of high-temperature superconducting (HTS) cables, uniform physical and geometrical properties of the tapes are usually assumed. However, commercially available coated conductor tapes present a certain nonuniformity of their transport capability—namely their critical current—along the length. In addition, when coated conductor strands are compactly assembled to form a Roebel cable, their arrangement is far from the ideal one. In this work, we calculate the influence of $I_{\rm c}$ nonuniformities and of nonperfect strand alignment on the critical current of Roebel cables made of an HTS-coated conductor tape. For this purpose, we perform a statistical analysis using a recently developed and freely available open-source code to calculate the critical current of Roebel cables. We find that, for the considered cases, the nonuniformity of the strands’ $I_{\rm c}$ can have a significant impact on the final critical current of the cable, whereas the influence of the misalignment of the strands is rather low.