AC Loss Investigation for HTS Stacked Cable with Optimized Gaps among Tapes

The cable stacked by high temperature superconducting tapes have strong anisotropic magnetic field dependence due to the fundamental anisotropic property inherited from ReBCO materials. With the number of tapes increasing, the maximum perpendicular field components appearing around degrade the critical current and carry current capacity of the whole conductor, and even cause significant AC loss during practical operations. To reduce the ac loss of the stacked conductor, this paper investigates different gap optimization methods in non-twisted stack of ReBCO tapes. Finite element simulations and performance comparisons a stacked conductor (10 tapes) without any gap, and with uniform gap schemes are presented. The results obtained show that the gap optimizations have much better effects towards AC loss reduction compared to a direct stacked tape. Designs based on non-twisted stacks can be simpler, more robust and cost effective than twisted ones. Therefore, this gap optimization methods among stacked tapes can be well expected to explore some high current design and performance evaluation schemes for large-scale HTS magnet developments and applications.