Magnetization AC losses in multilayer superconducting round cables with coinciding and opposite lay angles

Abstract

Superconducting cables with a circular cross-section are attractive for some applications like power transmission lines, current leads, and big magnet coils. In the case of Coated Conductor (CC) tapes, such an arrangement can be achieved by wrapping the tapes in a helical fashion around a circular former. While a braid from Cu wires serves as the core for the CORC™ cable, in the Conductor-On-Round-Tube (CORT) the CC tapes are laid in several layers on a tube. Traditionally, the tapes in the neighbour layers are wound following an alternating sense of helicity. Then, the tape edges raised due to the Poisson effect present local surface irregularity pressing into subsequent layers. We have found that this effect is less deteriorating in the case of coinciding lay angles because then the tape edges create imprints that are parallel to the tape length. Here, we present the result of investigating the AC loss performance of this innovative arrangement and its comparison with traditional architecture. Both verification possibilities - experimental testing of small laboratory models, and numerical modelling have been used for this purpose.

Optimization of REBCO Tapes through Division and Striation for Use in Superconducting Cables with Low AC Losses

“…When the HTS tapes are wound helically around a circular former, the tape edges are raised as a consequence of the Poisson effect. This causes indentations in the tapes in the subsequently wound layer of the cable [36]. Tape edges with additional turnings may introduce undesirable damage into the superconducting layer when the tapes are coiled.…”

Numerical study on the transport current distribution in the multi-layer CORC coil

“…superconducting cables has been proposed and manufactured, such as Roebel [8,9], twisted stacked-tape cable [10,11] and conductor on round core (CORC) [12][13][14][15]. With the advantages such as good isotropy [16] and low AC losses [17][18][19][20], the CORC cable is considered as a good candidate for fusion magnets and attracting more and more research interest [21][22][23].…”

HTS conductor coil by in-situ winding technology for large-scale high-field magnet

“…At present, there are various forms of HTS conductors, such as twisted stacked-tape cable [3,4], quasi-isotropic strand [5][6][7], ROEBEL Assembled Coated Conductors [8,9], conductors in tube [1], Cross Conductor [10], soldered stacked-square [11][12][13] and conductor on round core (CORC) [14]. The CORC has some advantages in higher current carrying capability [15,16] and lower AC loss [17][18][19][20][21].…”