Power transmission cables - Technologies. Features

The articlePower transmission cables is the subject of two articles:

• [D 4520] Technologies. Features ;

• Applications;

and the subjects covered are not independent of each other. Readers will often have to refer to the other article.

Today, two techniques are used to transport energy between production plants and consumption centers: overhead lines and underground cables.

Overhead lines, at high and very high voltages, are preferentially used because of their lower cost (ratio of around 3 to 5 for high voltage (HT) and 10 to 20 for very high voltage (VHV)).

Underground insulated cables are mainly used, at least until now, for the transmission and distribution of electrical energy in densely urbanized areas around or inside major cities, sometimes to solve specific local technical or environmental problems for which the installation of overhead lines is difficult or impossible. However, underground cables are increasingly used for medium voltage (MV), even in rural or semi-rural areas. What's more, recent advances in HV technology will make undergrounding easier in the near future.