HVDC Italy–Corsica–Sardinia
The HVDC Italy-Corsica-Sardinia (also called SACOI; Sardinia-Corsica-Italy) is used for the exchange of electric energy between the static inverter plant Suvereto on the Italian mainland, the static inverter plant Lucciana on Corsica and the static inverter plant Codrongianos on Sardinia.
First used in 1965 as mono-polar line, today this takes the form of a bi-polar high-voltage direct current (HVDC) line. It consists of three overhead line sections: one on the Italian mainland with a length of 50 kilometers, one on Corsica with a length of 167 kilometers and one on Sardinia with a length of 87 kilometers. In addition to this, there are two submarine cable sections: 103 kilometers (between Italy and Corsica) and 15 kilometers (between Sardinia and Corsica).
Static inverters for this line, which can transfer a maximum power of 200 MW at a voltage of 200 kV are in use today. Until the 1990s mercury vapor rectifiers were used, which have now been replaced by thyristors. In 1992 a second pole was taken in service, which can transfer 300 MW at a voltage of 200 kV. In contrast to most other installations for high voltage direct current transmission this system is a multipoint system making thus possible the energy exchange between several static inverter stations.