AC Loss Reduction of Superconducting Power Transmission Cables Composed of Coated Conductors

TLDR

AC losses in power transmission cables made of coated conductors can be potentially small. The study explores a strategy to reduce AC losses in such cables. Numerical analysis of mono‑layer conductors and single coated conductors, including substrate effects, showed that narrowing conductors and reducing spacing lower perpendicular magnetic fields and thus AC losses. Experimental validation with short mono‑layer conductors confirmed the principle, and a 1 kArms three‑layer conductor with a 19.6 mm diameter achieved an AC loss of 0.054 W/m at 1 kArms.

Abstract

AC losses in power transmission cables composed of coated conductors could be potentially small. A strategy to approach their potentially small AC loss was studied. AC losses in mono-layer conductors for cables were calculated numerically in order to show the principle for AC loss reduction: use of narrower coated conductors and/or decrease in space between conductors reduce the magnetic field component perpendicular to the wide face of coated conductors, and they are effective for AC loss reduction. This principle was confirmed experimentally by using short mono-layer conductors. Based on the principle, 1 kArms-class three-layer conductors were fabricated, and AC loss of 0.054 W/m at 1 kArms was achieved in a three-layer conductor whose outer diameter is 19.6 mm. The influence of a magnetic substrate on the AC losses in a single coated conductor and a mono-layer conductor for a cable was studied numerically.