The ac losses of (Bi,Pb)SrCaCuO tapes and wires and a YBaCuO tape have been
measured in self and applied fields. The transport losses of the YBCO tape
are much higher than any predictions using the critical state model. In th
is situation, the Bi-2223 wires and twisted tapes have the lowest losses. I
n applied perpendicular fields the losses of all conductors are currently t
oo high and should he reduced, The Bi-2223 wires are the most flexible and
prov ide the greatest scope for further loss reduction in the short to medi
um term.