Numerical analysis of AC loss and current distribution characteristics of co-axial multi-layer high temperature superconducting cable

A numerical model to calculate the inter-layer current distributions and the AC losses in co-axial multi-layer cable conductors was developed. The inter-layer current distributions and the AC losses in 4-layer cables were numerically calculated for various combinations of twist pitches and twist directions of the cables. With the numerical model, the twist pitch combinations to equalize the inter-layer current distribution and to reduce the AC loss were also investigated. The analytical results showed the remarkable dependence of the losses and the current distributions on the twist pitches and the directions of the cables. The optimized cable structures were discussed by the numerical results.