JICABLE'07 FINAL SYNTHESIS

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JICABLE 2007 session held in Versailles , France from June 24 to 28^th gathered more than 600 delegates coming from more than 50 different countries around 175 communications; these publications from 28 countries were organized in 20 oral sessions and 4 poster sessions.

The success of this conference reflects the continued level of activity of the cable sector at world level and the increasing demand of underground cables. Nowadays, developments of power cables technologies are growing due to :

the necessary development of networks, mainly in urban area,
inter connexions,
the increased demand to connect new production plants without green house effect,
environmental and societal requirements.

Present projects allow to optimise and to make cables and accessories more reliable as well as to simplify cable laying methods. These evolutions aim at reducing project costs with underground cables and to increase their competitiveness compared to overhead lines solutions.

Utilities have shown their interest in developing underground distribution network using proven reliable components. Among the discussed subjects we would highlight the growing importance of field measurements, on service monitoring and diagnostics, estimation of remaining life time of installed networks.

New highly reliable cables systems with low environmental impact were presented whose cost remains a key dimensioning parameter.

Regarding energy transmission, JICABLE 2007 was the opportunity to present many AC installations or projects proving the maturity of XLPE cables technologies up to 500 kV. These installations or projects reached a few tens kilometres in lengths using premoulded accessories, compensations of the reactive power for the longest links and optimized installation methods.

We have had the opportunity to review the realizations of the 400 kV, 16 MVA, 20 km long link in the London's tunnel between St John's Wood and Elstree , as well as the first 345 kV, 6 MVA, 34 km long extruded link installed in the Connecticut (USA) on October 2006.

At the same time in parallel with these new technologies, many contributions dealt with operating, ageing and maintenance oil paper insulated cables still widely in service within transmission networks.

In the field of industrial cables, fire behaviour remain to be a major concern, like the resistance against chemical damages for oil industry.

Diagnostic methods for cables and accessories are improving : on-site partial discharge measurement, on site temperature monitoring using optical fibres, which give operators methods to optimize underground lines operations.

Improvement of on-site test methods for power cables is still a current concern, often associating partial discharges measurements to voltage tests application.

Experiences of retrofitting, upgrading or even uprating lines were presented by utilities with the cooperation of manufacturers. Jicable prize was awarded to the communication « Evaluation of the condition and performance of underground high voltage fluid filled links at Hydro-Québec » that shows that environmental concerns are well taken into consideration for cables design and operating : material selection and renewability, works' implementation conditions, EMF decreasing, underground lines combination with the environment.

New technologies were brought up with industrial realizations more particularly in the superconductivity field or in N2/SF6 gas insulation line realizations. Opening session of Jicable started with the nanotechnologies and their potentiality of making great strides on material matrices for future power energy cables.

Number of DC underground lines keeps growing: realizations or projects of submarine cables were shown for tension level until 450kV. More precisely, we were aware of the challenges of the second link between Spain and Morocco, as well as the qualification test difficulties and commissioning for the XLPE 420 kV first link in Norway in the summer 2006.

Finally, to conclude Jicable Conference, a specific oral session and a round table was dedicated to the economical elements of insulated power cable links: this is a priority for utilities which have to look for high reliability products with costs as close as possible than those offered by equivalent overhead lines. Over 1000 MVA, cost gaps, between under and over head lines, are still huge and invite to improve component technologies and to optimise laying techniques.

In conclusion, the high level of the communications at Jicable Conference offers a large opportunity of exchanges within all workers of Insulated Power Cables field: cable manufacturers, accessory manufacturers, utilities, consulting people, test and research laboratories for example.