AC Loss Property of a Two-Dimensional Array of REBCO Superconducting Tapes

To design a safe superconducting motor with high power density for aircraft applications, an accurate estimation of the AC loss in superconducting windings is required. This study investigates the AC loss characteristics of a two-dimensional array of REBa2Cu3Oytapes arranged in both the width and thickness directions, representing the cross-section of a motor winding. The AC loss was evaluated experimentally and numerically, with the key parameters being the number of tapes and the gap distance between adjacent superconducting layers. The AC loss behavior is expressed as a power function,a'bmγ', wherebmis the normalized field amplitude, anda'andγ'are the fitting parameters. Botha'andγ'were found to follow an exponential approach with respect to the number of tapes in the width direction. Additionally,a'was found to be inversely proportional to the number of tapes in the thickness direction. For these properties, quantitative expressions were derived and confirmed to correspond to the measured and calculated results.