3. AC-DC network association study

3.1 HVDC "bi-terminal" system

The system is said to be "bi-terminal" when it only allows exchange between two "rectifier/inverter" converter stations. However, AC networks can be of different voltages and, above all, frequencies.

This is currently the most widely used type of system. The DC network, generally a very high-voltage system known as HVDC (High Voltage Direct Current), acts as a kind of "relay" for the conventional AC network, enabling electrical energy to be transported, usually offshore.

Submarine transmission via three-phase cables very often causes nuisance by emitting low-frequency waves that interfere with certain marine signals.

More recently, terrestrial links have also been installed or planned,...