1. Drivers

1.1 Metals used and conductor construction

Bare conductors, used in the construction of overhead lines, are cables made of round wires or, in exceptional cases, trapezoidal or Z-shaped wires.

Low-resistivity conductive metals are in short supply for these cables. The only ones currently used are high-purity aluminum in its hard-wrought form, and an aluminum alloy called almelec. The characteristics of these metals have changed little in recent decades, and their maximum operating temperature cannot exceed 100°C. However, certain conductive metals, such as annealed aluminum, or certain alloys should enable higher operating temperatures, of the order of 200 C, and are currently being tested