Numerical Study on AC Loss of Soldered-Stacked-Square(3S) HTS Wire with 1 mm Width

Soldered-Stacked-Square (3S) high temperature superconducting (HTS) wire is a novel structure of second generation (2G) HTS wire which has been developed through narrowing, stacking and soldering processes. AC loss is one of the most important parameters that needed to be confirmed when the 3S wires are applied in alternating current or magnetic field circumstances. In this paper, we proposed a three dimensional (3D) finite element method to calculate the AC loss of the 3S wire. A homogenization method is introduced to simplify the simulation process and improve the simulation speed. The model is based on E-J power law and H-formulation in 3D space. The simulated 3S wire is made of six narrow HTS tapes. The validity of the model is verified by the experimental results. Moreover, the simulated results are also compared with the theoretical results obtained from the elliptical and thin strip equations of Norris model. In conclusion, the AC loss of 3S wire lies between two theoretical values. The work in this paper would be meaningful to understand the electromagnetic characteristics of 3S HTS wire. It is also a preliminary study on the twisted 3S HTS wire and 3S HTS wire solenoid coil.