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DEVELOPMENT OF HIGH CURRENT CARRYING CONDUCTORS FOR CABLES USING HIGH TEMPERATURE SUPERCONDUCTORS

Objective


The partners have explored a number of materials and fabrication techniques with a view to determining the combination best suited for the construction of high temperature superconducting power cables. The fabrication of conductors containing the Y-123 phase of thallium-based materials was explored with promising results, but these conductors had not attained the required performance level over the long lengths needed for the construction of the demonstrator conductors by the end of the project. Numerous lead-based, bismuth-based and other 1212-type phases were also systematically synthesised and tested, but none of these materials exhibited superconducting properties suitable for HTS tapes when prepared under ambient conditions or under 20 kPa pressures of oxygen.

Both within this project and elsewhere in the world, the PIT processing of the (Bi,Pb)-2223 phase has emerged as a cheap and reliable manufacturing method for producing HTS tape with critical current densities suitable for use in cables. The present study first examined the technical issues and performance of short samples. Criteria were established for the selection and preparation of precursors, and good reproducibility of tapes has been demonstrated for Jc values in the range 10 - 20 kA/cm{2}. Due to the relative ease of scaling up the powder-in-tube technique, long lengths of multi-filamentary tapes were fabricated and processed allowing two cable models to be designed and built with critical currents at 77 K and self-field of 110 A and 430 A. The partners have therefore established the essential capabilities to enable the next stage of development, the building of test sections of HTS power cable, to commence.
High temperature superconductors have the potential to significantly reduce both the capital cost and energy loss penalties traditionally associated with underground power cables. The proposed research focuses on the fabrication of long lengths of high temperature superconducting wire/tape by three fabrication routes:

1. Powder in tube.

2. Doctor Blade casting.

3. Laser processed thick films.

The fabrication task is directly supported by a materials processing task whose aim is to improve processing routes to provide controlled,well characterised conductors. The processing and fabrication tasks are in turn supported by a parallel materials research effort which builds on the recent discovery of a new superconducting material by the partners and seeks to improve our understanding of the existing cuprate materials and thence to identify materials with enhanced properties. The successful outcome of the proposed development will encourage the widespread use of high temperature superconducting technology throughout the electricity generation and supply industry.

Funding Scheme

CSC - Cost-sharing contracts

Coordinator

GEC MARCONI LTD
Address
Hirst Research Centre Elstree Way
WD6 1RX Borehamwood
United Kingdom

Participants (4)

ALCATEL CABLE
France
Address
30 Rue Des Chasses
92111 Clichy
Bicc Plc
United Kingdom
Address
Quantum House, Maylands Avenue
HP2 4SJ Hemel Hempstead
Pirelli SpA
Italy
Address
Viale Sarca 222
20126 Milano
SIEMENS AG
Germany
Address
Paul-gossen-straße 100
91050 Erlangen