Efficient finite element analysis of electromagnetic properties in multi-layer superconducting power cables

It is highly beneficial to reduce AC losses in multi-layer superconducting power cables. For this purpose, each superconducting layer is wound with a different twist pitch on a former so as to balance current distribution among layers. Finite element analysis makes it possible to show electromagnetic properties in superconducting layers visually, which is useful for discussing methods to enable further loss reduction. However, making a numerical analysis model of a multi-layer cable which is faithful to its geometry is highly complicated and troublesome as the model requires a correction each time the set of twist pitches needs to be changed. The authors have developed a new method to analyze such a cable by introducing anisotropy on the conductivity. In this paper, the method and the effects are discussed and compared with experimental results.