Abstract
A high temperature superconducting (HTS) cable has been researched in many countries. We have studied an HTS tri-axial cable that is composed of three concentric layers. A tri-axial cable is more advantageous than a triad co-axial cable that is composed of three cores in one cryostat. Since conventional tri-axial cables had not realized three-phase equilibrium, we proposed a tri-axial cable composed of two longitudinal sections with different twist pitches. However, it is too difficult to realize the designed twist pitches in manufacture process. Therefore, we investigated the influence of fabrication errors in the twist pitches on electromagnetic properties of a tri-axial cable. In this paper, we evaluated the combination of the twist pitches that realize the maximum imbalanced ratio. Then, we considered the worst error in twist pitches and how long the tri-axial cable can transmit electricity safely.
