50-M LONG HTS CONDUCTOR FOR POWER CABLE

The long conductor fabrication is one of key technologies to realize t he High-Tc superconducting power cable. A 50-m long conductor was fabr icated by helically winding the High-Tc superconducting tape onto a fo rmer with a minding machine. The conductor consisted of ten layers of Ag-sheathed Bi-2223 tape which had a high critical current density of 10,000 A/cm(2) (at 77 K). AC losses and layer-by-layer current distrib ution were measured, feeding AC current of 100 to 2,000 Arms to the co nductor cooled by LN2. The results showed that most of the current flo wed in the outer layers where the impedance was low, and that AC losse s were remarkably reduced by making the current distribution uniform.