Effect of Multilayer Configuration on AC Losses of Superconducting Power Transmission Cables Consisting of Narrow Coated Conductors

Superconducting power transmission cables are regarded as a key to realize the next-generation power systems with high capacity and high efficiency, and 4 mm coated conductors have been broadly used as a standard to develop such cables. Recent research shows that, comparing with standard 4 mm coated conductors, narrow 2 mm coated conductors prove to have a pronounced advantage on AC loss reduction for superconducting cables. Besides, thanks to laser cutting technique, it became possible to cut wide coated conductors into small tapes as narrow as 2 mm without considerable damage. Hence, narrow 2 mm coated conductors are attracting more and more attentions and have turned into a potential option for developing more efficient superconducting cables. So far, there have been many discussions on AC loss characteristics of the superconducting cables consisting of 4 mm coated conductors, whereas, the studies on cables comprising narrow 2 mm coated conductors are very few. This paper is to clarify the AC loss characteristics of superconducting cables consisting of narrow 2 mm coated conductors, especially to analyze the dependence of AC loss on the number of layers, with the intention of studying the effect of multilayer configuration on AC losses of such cables. A set of numerical models simulating such superconducting cables have been developed by applying 2-D FEM method. This set of models comprises 1-layer, 2-layer, 4-layer and 6-layer cables, with the former three types of cables as practical cables under development and the last one as a future option. Narrow 2 mm coated conductors with the same critical current and current distribution were selected for all the cables. Within these cables, numerical electromagnetic field analysis has been carried out for AC loss calculation and comparison.