The AC Loss Estimation of Bi-2223/Ag Superconductor Tapes in Polygonal Configuration

In this paper, we have studied the electromagnetic phenomenon and AC losses of assembled high-T_c superconductor (HTS) tapes using the finite element method (FEM) approach. The model cable is composed of several Bi-2223/Ag tapes with polygonal shape on the cylindrical former that was arranged in parallel along the conductor axis. The HTS tape usually shows complex material properties, which are described by the nonlinear resistivity and the anisotropy against the external magnetic flux density as well as its angle. The numerical calculation was carried out considering the field dependence of critical current density and index value, which accounts for the anisotropy of the Bi-2223/Ag tape. The calculated AC losses were compared with the experimental results and with the theoretical values. It was observed that the analytic formulae are not proper to predict the AC loss of the multi-stranded conductor that is presented here. The adjacent tape´s effect of the conductor on the AC loss was also investigated and discussed.