AC Loss Modeling of Non-Standard Arrangements of Y-Ba-Cu-O Tapes in a Stack

In this work we propose semi-analytical models for computing alternating current (AC) power loss of stacks of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$N$</tex-math></inline-formula> high-temperature superconductor YBa<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub>Cu<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub>O<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">7-x</sub> (or Y-Ba-Cu-O) tapes with non-standard arrangements of tapes. Each stack is subjected to time-dependent magnetic fields perpendicular to the wide surface of the tapes with zero transport current. The models take into account screening of the interior superconducting layers in the stack from the external magnetic field. These models are validated by our experimental studies. As is also shown, the AC loss dependence on the arrangement of tapes in the stack can be quite strong, varying by factors up to ∼ 180× for temperatures 20–65 K, magnetic fields 2–5 T and frequencies up to 2 kHz.