AC transport losses under self fields in Ag-sheathed (Bi,Pb)2Sr2Ca2Cu3Ox conductors

The AC transport losses under self fields were investigated at 77 K on the Ag-sheathed (Bi,Pb)(2)Sr2Ca2Cu3Ox 19-filamentary untwisted and twisted (with a pitch of 13 mm) tapes. The filament twist neither causes notable influence on the loss behavior nor equalizes the current distribution in the filaments, although the main contribution to the losses comes from the hysteresis loss. Using the theory of Norris, numerical calculations on the AC transport losses were made for the models of parallel-conductors cables composed of a single-layer or a double-layer configuration using superconductor tapes with rectangular cross-section as the strands, in order to obtain a guide for design and construction of power cables toward a reduction of the transport losses. (C) 1997 Elsevier Science B.V.