  Numerical modeling of superconductors is widely recognized as a powerful tool
for interpreting experimental results, understanding physical mechanisms and
predicting the performance of high-temperature superconductor (HTS) tapes,
wires and devices. This is especially true for ac loss calculation, since a
sufficiently low ac loss value is imperative to make these materials attractive
for commercialization. In recent years, a large variety of numerical models,
based on different techniques and implementations, have been proposed by
researchers around the world, with the purpose of being able to estimate ac
losses in HTSs quickly and accurately. This article presents a literature
review of the methods for computing ac losses in HTS tapes, wires and devices.
Technical superconductors have a relatively complex geometry (filaments, which
might be twisted or transposed, or layers) and consist of different materials.
As a result, different loss contributions exist. In this paper, we describe the
ways of computing such loss contributions, which include hysteresis losses,
eddy current losses, coupling losses, and losses in ferromagnetic materials. We
also provide an estimation of the losses occurring in a variety of power
applications.
