  Different magnet applications require compact high current cables. Among the
proposed solutions, the Twisted Stacked Tape Cable (TSTC) is easy to
manufacture and has very high tape length usage efficiency. In this kind of
cables the tapes are closely packed, so that their electromagnetic interaction
is very strong and determines the overall performance of the cable. Numerical
models are necessary tools to precisely evaluate this interaction and to
predict the cable's behavior, e.g. in terms of effective critical current and
magnetization currents. For this purpose, we developed a fully
three-dimensional model of a TSTC, which not only takes into account the
twisted geometry of these cables, but is also able to account for the contact
resistances of the current terminations. The latter can have profound influence
on the way the current is partitioned among the tapes, especially on short
laboratory prototypes. In this paper, we first use the numerical model to
compute the critical current and the magnetization AC loss of a twisted tape,
showing the differences with the case of a straight tape. Then, we use it to
calculate the current distribution in a TSTC cable, comparing the results with
those experimentally obtained on a cable composed of four straight stacked
tapes. The results show the ability of the model to simulate twisted conductors
and constitutes a first step toward the simulation of TSTC in high-field magnet
applications. The presented modeling approach is not restricted to the TSTC
geometry, but may be used for any cable configuration with periodical
translational symmetry.
