A nonlinear model of silver sheathed Bi(2223) high temperature superconducting tape

The use of high temperature superconducting Ag sheathed Bi(2223) tapes as a component of a circuit requires a good understanding of their behavior in under-critical and upper-critical working conditions. We propose a modeling of such a device described by an inductance and non-linear resistors. Our model not only describes the AC behavior but represents more generally the dynamic behavior for frequencies below one hundred Hz and currents higher than the critical one. A special equivalent circuit configuration is considered to take AC losses into account. The identification of the model parameters can be performed by the electrical measurement of sample tapes using a lock-in technique.