The Effective Current and Magnetic Field Distributions for Reducing AC Losses in Coaxial Multi-Layer HTS Transmission Cable

We have investigated the relationship between current distribution and transport AC losses in coaxial multi-layer HTS transmission cables and clarified that the same layer current in conducting layers can reduce the transport AC losses effectively. It can be, however, considered that magnetization losses are much larger than the transport AC losses in a large transport current. Therefore, we analytically investigated effective current and magnetic field distributions for reducing total AC losses in an HTS transmission cable with a large transport current. The total AC losses in the case of the same applied magnetic field in the conducting layers were much smaller than those of the same layer current in the conducting layers. This result means that inhomogeneous current distribution is more effective for reducing the total AC losses than homogeneous current distribution. The total AC losses decreased with the electrical insulation thickness between the conducting and shielding layers; the electrical insulation thickness is one of the important parameters in terms of reducing the total AC losses