Dynamic resistance and total loss in a three-tape REBCO stack carrying DC currents in perpendicular AC magnetic fields at 77 K

Abstract In many high-temperature superconducting (HTS) applications, HTS-coated conductors carry a DC current under an external AC magnetic field. such operating conditions, dynamic resistance will occur when the traversing flux across HTS conductors. Consequently, loss within superconductors is composed of component arising from and magnetization due to This one critical issues for as persistent switches, pumps, rotating machines. this work, total in three-tape coated conductor stack were measured at 77 K perpendicular fields up 80 mT currents ( I dc ) c ). The was assembled three serial-connected 4 mm wide Superpower wires. results well supported by 2D H -formulation finite element modelling (FEM) broadly agree with analytical values stacks. FEM analysis shows asymmetric transport profiles central region superconductor. We attribute result superposition induced subcritical which explains why increase levels low onset i / much slower compared that single tape hence contribution smaller than tape. Dynamic becomes comparable = 0.5 greater 0.7. Both are those shielding effects. difference between Q behaviours variation penetration depths different field amplitudes.