Measurement and Simulation of Magnetization Loss in HTS Arrays

Large superconducting windings can be considered as assemblies of many arrays consisting of high-temperature superconductor (HTS) tapes. In HTS applications, they will be exposed to external fields with various orientations, resulting in magnetization loss (<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Q</i><sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m</sub>). Understanding the magnetization loss behaviors of HTS arrays is crucial for those HTS applications. In this work, we measure <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Q</i><sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m</sub> of single- and four-row arrays with one, two, and four columns at 72.23 and 145.51 Hz. We refer an array as <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">a</i>/<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">b</i>, where “<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">a</i>” and “<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">b</i>” represent the number of columns and rows, respectively. <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Q</i><sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m</sub> of the 4/1 and 4/4 arrays with various magnetic field angles is also measured. All measured <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Q</i><sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m</sub> results are compared with corresponding finite-element method simulations. Notably, the measured <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Q</i><sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">m</sub> per tape in the single-column arrays is smaller than that of the two-column arrays, while the four-column arrays exhibit the highest loss at low field (e.g., below 60 mT for the four-row array). On the other hand, simulation results on the arrays with up to eight rows and columns show that as the column count increases, the magnetization loss values become saturated due to the dominance of magnetization loss in the inner columns.