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

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 monolayer 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.

Calculating AC Losses in High-temperature Superconducting Cables Comprising Coated Conductors

“…1,2). The calculated self-field loss of a coated conductor in polygonal assemblies is reported to be smaller than that of a single isolated strip when calculated by the Norris equation [4][5][6]. However, as was observed in the experiment described in Section 3, the losses do not differ greatly.…”

“…The measurement results of the two types of three-layer cables have been reported by Amemiya et al [4]. Here, only the results of cable 3C-A are discussed.…”

“…The AC loss of a coated conductor in a monolayer cable is decreased when compared with that of a single isolated strip. The loss in an isolated coated conductor is primarily due to a perpendicular field, which is reduced in the gap between the strips [4][5][6]. The AC loss, including the interaction of coated conductors in an HTS cable, is calculated by the two-dimensional finite element method (2D FEM).…”

Numerical minimization of AC losses in coaxial coated conductor cables

“…One is to arrange the tape layer in the form of a cylinder to reduce the magnetic field component perpendicular to the cable surface [9,10] whereas the other is to choose optimal layers' lay angles and tape numbers. The losses can be significantly reduced with the lay angles which homogenizes the current sharing between the layers [11,12].…”

Superconducting fiber

“…[6][7][8][9] The cable structures, though, are often very exotic and require complicated manufacturing processes. [10][11][12] Simple and cost effective superconductor cable designs and fabrication processes are required to enable wide implementation. However, not much attention has been paid to processing schemes or possible adaptations to more mature processes that can be readily scalable.…”