3D FEM Analysis of Effect of Current Distribution on AC Loss in Shield Layers of Multi-Layered HTS Power Cable

By modeling spirally wound superconducting tapes as conductors having an anisotropic conductivity and using the periodic boundary condition, the analysis region is considerably reduced in 3D edge-based hexahedral FEM analysis. By using this model, the AC transport characteristics of the co-axial five-layer cables (composed of three conductor layers and two shield layers) are studied, and the effect of current distribution among layers on AC loss in shield layers is investigated. It is possible to control the current distribution in the shield layers by adjusting the twist pitches of shield layers. It is shown that the uniform current in each layer dose not give the minimum AC loss and the current should flow in the inner shield layer in order to reduce the AC loss of shield layers.