Current distribution analysis in tri-axial HTS cable considering three phases

High Temperature Superconducting (HTS) cables have been recently studied because of low loss and compactness, compared with conventional copper cables. We, so far, analyzed current distributions in a single-phase coaxial cable with and without shield current. Three-phase cables are usually composed of the three single-phase cables. However, a tri-axial cable, composed of concentric three phases, has more advantages compared with the three coaxial cables, because of reduced HTS tapes and leakage field. We derive equations governing layer current and current density distributions in the tri-axial cable considering other phases. The current and current density distributions are described as explicit functions of cable construction parameters, such as radius, twist pitch and twist direction. We calculate the homogeneous current and current density distributions by choosing adequate cable construction parameters.