Hysteretic ac loss of polygonally arranged superconducting strips carrying ac transport current

The hysteretic ac loss of a current-carrying conductor in which multiple superconducting strips are polygonally arranged around a cylindrical former is theoretically investigated as a model of superconducting cables. Using the critical state model, we analytically derive the ac loss Q(n) of a total of n strips. The normalized loss Q(n)/Q(1) is determined by the number of strips n and the ratio of the strip width 2w to the diameter 2R of the cylindrical former. When n > 1 and w/R < 1, the behavior of Q(n) is similar to that of an infinite array of coplanar strips. (C) 2008 American Institute of Physics.