Inga Kolwezi

The Inga-Kolwezi link (formerly the Inga-Shaba link) was initially a ± 500 kV, 560 MW HVDC power transmission system. This HVDC transmission line continues to deliver power despite instability in central Africa. The line's extreme length and difficult logistics resulted in a decision to build two monopolar lines with four switching stations. Converter stations were built so the two converter poles can be operated in parallel with ground return, in case of a monopolar line outage. 

Hitachi Energy signed a contract for the converter stations in 1973, but due to civil unrest in the country (formerly called Zaire), the transmission line was not put into service until 1982. The Inga-Kolwezi link is owned by DRC's national electricity utility, Société nationale d'électricité (SNEL). Each valve hall is equipped with six air-cooled double valves, which at the time featured the highest valve voltage rating in the world. Every single valve has 258 series-connected thyristors.