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Within the past few years robust superconductor known as Secondgeneration (2G) High Temperature Superconductor (HTS) were developed for different industrial applications. Their fabrication includes a phase of large bending, which induces both axial and shear stresses, which could lead to the degradation of the super-conductive substrate. The design of HTS requires analysis of the stress and strains induced during their fabrication. The use of the finite element method for the analysis of this complex material requires large meshes and computation time, because of the ultra-small thickness of the supra-conductive substrate. In this paper, we present a simplified model, which is based on the classical beam theory together with the discretization of each layer in small sub-layers working under purely axial stress. The model takes into consideration the plastic behaviour of the HTS constitutive materials. The model is validated by its confrontation to finite element analyses. Then it is used for the optimal design of HTS by the analysis of different industrial configurations. Analyses lead to some recommendations concerning the optimal configurations that reduce the stresses in the supra-conductive substrate. [ABSTRACT FROM AUTHOR]

Abstract: The LNCMI, the national French high magnetic field facility, provides high fields generated mainly by resistive magnets. Because of the forecast increasing price of electricity, LNCMI has a strong incentive to participate to the development and characterizations of HTS conductors in view of their use for the generation of strong field. Latest YBCO coated conductors have improved properties showing a great potential with that respect, without excluding Bi2212 and MgB2 for particular cases. We present the existing set-up to measure short straight or VAMAS type coil samples at variable temperature and high field up to 30 T, and some measurements obtained on different HTS conductors, Bi2212 round wires and YBCO coated conductors. We also report on the first results obtained at 18 T with a pancake coil made of commercial YBCO coated conductor tapes on a newly developed solenoid test bench. [Copyright &y& Elsevier]

Key components for the power transmission and distribution for the future grids are superconducting cables. The energy network in highly populated areas will soon fully benefit from this technology, in particular for the retrofitting of the existing cables. However retrofitting the existing grid in underground structures (pipes, pits, turn), requires cables as small a diameter as possible. The HTS cable core is generally manufactured by laying tapes around a former with a diameter of about 25 mm to prevent any damage to the tape during the cabling and the handling operations. However in this configuration, the former cannot be used to transport the current. This triggered a new approach in cable design involving round 2G HTS wires with a diameter from 1 to 2 mm. They can be assembled to build a small cable core with a high ampacity. The benefits of this new wire design on power cables are discussed. The first results on different manufacturing processes and the characterizations of the 2G HTS wires are presented. [ABSTRACT FROM PUBLISHER]

The second generation (2G) HTS conductors, the YBaCuO Coated Conductors, show very exciting performances in terms of critical currents under very high fields whereas their mechanical properties, the key issues for very high field magnets, are outstanding for the IBAD (Ion Beam Assisted Deposition) route. Preliminary measurements have shown critical currents Ic above 500 A at 15 T and 4 K on commercial YBCO coated conductors. They are now available in reasonable length and manufacturing focus to provide reliable, consistent performance conductors. With these high critical current and tensile strength above 600 MPa, these conductors are very promising for making HTS superconducting coils able to generate very high field. But very few characterizations exist above 20 T. LNCMI is one of the few facilities in the world where such measurement can be performed. [ABSTRACT FROM PUBLISHER]

Superconducting links are an innovative solution for bulk power transmission, distinguished by their compact dimensions, high efficiency and small environmental footprint. As with any new technology field, there is a large amount of design possibilities for such links, each of them having a profound impact on the system configuration. For instance, changing the material can imply a change in the working temperature from 20 to 70 K and has consequences on the maximum link length. This article presents the dichotomic decision possibilities for the optimized design of a high-power superconducting link, focusing on some of the key components of the cable system. The complex design optimization process is exemplified using the European project Best Paths, in which the first 3-gigawatt-class superconducting cable system was designed, optimized, manufactured, and successfully tested. [ABSTRACT FROM AUTHOR]