Numerical study on AC loss minimization of multi-layer tri-axial HTS cable for 3-phase AC power transmission

This paper presents numerical studies on structures to minimize AC losses in high temperature superconducting tri-axial multi-layer three-phase cable conductors. The Simulations were performed for tri-axial cables of 2-layer/phase configuration under 3-phase AC operation. From the numerical results, the relation between the AC loss and the layer-to-layer current sharing showed that the AC loss can be minimized by adjusting the layer-to-layer current sharing. The reason was clarified from the numerical data of the current density profiles across the superconducting layers. Based on the numerical analysis, the twist pitch formulation for the AC loss minimization was obtained.