  In this paper we develop a method based on the critical state for calculating
the current and field distributions and the AC losses in a cable made of curved
thin superconducting tapes. The method also includes the possibility of
considering spatial variation of the critical current density, which may be the
result of the manufacturing process. For example, rare-earth based coated
conductors are known to have a decrease of the transport properties in near the
edges of the tape: this influences the way current and field penetrate in the
sample and, consequently, the AC losses. We demonstrate that curved tapes
arranged on a cylindrical former behave as an infinite horizontal stack of
straight tapes, and we compare the AC losses in a variety of working
conditions, both without and with the lateral dependence of the critical
current density. This model and subsequent similar approaches can be of
interest for various applications of coated conductors, including power cables
and conductor-on-round-core (CORC) cables.
