AC losses in high-temperature superconductors

Ceramic superconductors experience losses when carrying alternating currents. A practical situation of particular importance for the possible use of such superconductors in power apparatus is 50 Hz excitation at liquid nitrogen temperature (77 K). A theoretical investigation of the one-dimensional AC current flow and associated losses in a ribbon or tape of YBCO, the cross-section of which is assumed to be much wider than its thickness, is considered in this paper