A new cabling machine was constructed for conductor on round core (CORC)-like cable production. Its design allowed us to produce a cable with two layers in one run, each comprising four superconducting tapes. The cable of length of 40 m was made at a production rate of 6 m h−1 by this machine. It consisted of eight Furukawa-SuperPower tapes of width 4 mm and length 50 m wound in two layers on Cu tube with outer diameter 6.35 mm. To detect the influence of the cable winding technology on the superconducting tapes’ properties their critical currents were measured individually on the as-produced cable in the form of a one-layer coil. Afterwards the critical current of the one-layer coil was measured by monitoring the voltages on all tapes while increasing the coil current. The average of these voltages was utilized for coil critical current determination. Then the solenoid with four layers each containing 20 turns was created from the cable and the same measurement procedure was performed to check the influence of cable bending on the solenoid form. The results of these characterizations exclude critical current degradation for any tape of the cable used for solenoid preparation. The measured solenoid critical current of 622.8 A is lower than the simple sum 1240 A of the individual tapes’ critical currents due to the dependence of the tape critical current on the magnetic field. For all measurements the investigated object was immersed into a liquid nitrogen bath. In the case of the solenoid the bath was also cooled down to 66 K.
REBa2Cu3O7-x (RE—rare earth, Ba—barium, Cu—copper, O—oxygen) tapes used in common multilayer superconducting cables, such as Roebel cable, twisted stacked tape cable or vonductor on round core/tube (CORC ® /CORT), undergo shape modifications during the cable production. In particular, the tapes edges are regularly raised due to the Poisson effect during bending of tapes in the cable assembling process. This kind of deformation amplifies the local strain in subsequent layers, endangering the capability to transport electrical current. We explore such deformation by numerical and analytical calculations validated by experiments. Three-point bending device submerged in liquid nitrogen was developed for this purpose. We found that, if the orientation of Poisson effect deformations is along the tape length, the local strain is reduced and performance of the cable remains unaffected. In contrary, the local deformations at the crossings of tapes from subsequent layers represent a serious threat towards reaching a satisfactory critical current retention.
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.
In many applications, high temperature superconductor (HTS) tapes are placed on top of uneven surfaces. Because the electrical properties of HTS tapes are sensitive to mechanical loading, mechanical stress generated at such local imperfections can considerably decrease the critical current of a HTS tape. Then a method of predicting degradation of critical current from a numerical simulation would be helpful. We present the results of 3D mechanical finite element model analysis, using the software ANSYS for optimising the geometry of a round CORT (Conductor-On-Round-Tube) cable. In these simulations, the HTS tape is bent around a circular former of certain diameter with a surface imperfection. We used three parameters to characterize the imperfection geometry: diameter of the former, the height and the width of imperfection. In order to validate the mechanical simulation results, we performed in-situ measurement of critical current of HTS tape.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.