Abstract
The AC transport loss properties under self-fields at 77K have been investigated for simple cable conductors composed of 4 or 8 pieces of Ag-sheathed Bi2223 multifilamentary tape with different filament arrangements. The AC transport losses per cycle are nearly independent of frequency from 30 to 200Hz for each conductor, indicating that the main contribution to losses comes from the hysteresis loss in the superconductor regardless of filament arrangements in the tape strand and the arrangement of tape strands in the conductors. The loss values of conductors strongly depend on the filament arrangements in the tape strands. The conductors composed of tape strands with sectioned filament arrangements have lower losses than those without sectioned filament arrangements, because the field-free core (FFC) in the former is sectioned into some parts in the filament group. The AC transport losses of cable conductors are also influenced by the number of tape strands. The loss values are decreased by increasing the number of tape strands, which is explained by calculated results for density distributions of AC transport losses per cycle in a tape strand. These results show that improvement in the filament arrangements in tape strands and the arrangement of tape strands in conductors are quite important to suppress the losses generated in cable conductors under AC current transmission.
