NEXANS, a worldwide expert in the cable industry, and RTE, France’s electricity transmission system operator (TSO), are collaboratively conducting a field trial of the innovative Lo-Sag conductor technology which uses a carbon fibre composite core. This field trial involves about 1 km of high voltage – 90 kV – overhead line being upgraded between Bellac and Saint-Martin-Terressus. This is the first time that this new conductor design is being deployed in Europe.

RTE has undertaken the trial of this innovative cable to meet its ongoing objective of continuously improving the quality of its power delivery infrastructure.

If the trial is successful, such overhead line technology could be deployed to upgrade power grids for optimum performance because this solution makes it possible to control costs while minimising environmental impacts.

In contrast with conventional steel-core overhead line conductors, Lo-Sag features a carbon composite core with a much lower coefficient of thermal expansion, which allows higher power transmission capacity.

The three-phase 90 kV Limousin trial installation replaces older steel cables while making use of most of the existing infrastructure such as pylons, thanks to the light weight and low expansion of the new conductors.

Comprehensive testing of the Lo-Sag technology will take place throughout the course of the year, with the objective of checking compatibility with the existing grid as well as reviewing its mechanical properties and the capability to withstand France’s variable climate, including combinations of wind, ice and snow. The aim is also to evaluate the ageing of this new cable compared to a “conventional” conductor.

The conductor for the RTE trial was manufactured at Nexans’ factories in France, Belgium and Germany. Nexans has the manufacturing capability in place to ramp up Lo-Sag production as orders for major projects in Europe are received.

With energy as the basis of its development, Nexans is a global player in the infrastructure, industry, building and Local Area Network (LAN) markets. The company has an industrial presence in 40 countries and commercial activities worldwide, employing 25,000 people.