Fast modeling approach of large-scale non-inductive HTS coils under different current supply

Abstract

This paper presents a fast-integral modeling approach for the design and characterization of large-scale non-inductive high temperature superconducting (HTS) coils made of first-generation HTS tape. The integral modeling is combined with a strategy of far tape approximation allowing to model a reduced set of consecutive tapes instead of the entire coil. It makes it possible to estimate the losses and the current density distribution in the coil, under different current supply. This leads to a considerable reduction in the computation time. The calculated AC losses show a good agreement with the Norris ellipse formula and measurements, highlighting the importance of considering the elliptical section of the superconductor in the tape, in the modeling. The developed modeling approach is in particular useful in the AC + DC mode, where Norris’s formulas cannot be used to determine the losses. Besides, some interesting phenomena have been observed, related to the current distribution in the tapes at different AC and DC current values.