New Experimental Method for Investigating AC-losses in Concentric HTS Power Cables

TL;DR

This paper introduces a novel experimental technique for accurately measuring AC-losses in concentric HTS power cables, overcoming previous challenges caused by uneven current distribution due to contact resistances.

Contribution

The authors present a new 2-meter-long three-phase concentric cable model with a unique arrangement that allows precise control and measurement of currents and AC-losses in HTS cables.

Findings

Preliminary results demonstrate the effectiveness of the new measurement setup.

The method enables unambiguous electrical property measurements of HTS cables.

The setup accounts for inductive coupling and contact resistances, improving accuracy.

Abstract

The optimization of a HTS cable design with respect to AC-losses is of crucial importance for the economic viability of the respective concept. However the experimental determination of AC-losses is not straightforward since for short cable samples the distribution of current among the super-conducting tapes is mainly determined by the contact resistances of the individual tapes. The resulting inhomogeneous current distribution definitely falsifies the results. To solve this experimental problem we present a new experimental technique. The setup is a 2m-long three phase concentric cable model for which, within each phase, the superconducting tapes (up to 30) are connected in series. The Cu-braid backwards conductors were assembled in a rotational symmetric cage type arrangement, such that their self fields at the cable cancel. If experimental peculiarities of this setup, as the strong inductive coupling between the phases and the suitable positioning of the voltage contact leads, are correctly taken into account, the currents can be controlled independently and the electrical properties of the cable can be measured unambiguously. In this paper preliminary results are presented. The work is part of the German government funded cable project AMPACITY (1 km / 20 kV/ 2 kA)