SVCs for voltage support and stability enhancement in a 220 kV ore mine feeder
Two Static var compensators (SVC) supplied by Hitachi Energy went on line in 2012 at the Oyu Tolgoi ore mine in Mongolia. Each SVC is rated at 100 Mvar (inductive) to 100 Mvar (capacitive) at 220 kV system voltage.
Oyu Tolgoi is a copper and gold mine located in the southern Gobi Desert, jointly owned by Rio Tinto, Ivanhoe Mines and the Mongolian government. Production from an open pit and underground shafts will be processed in a primary crusher and concentrator. The concentrate is transported to refineries located elsewhere. The site is remotely located, with an elevation more than 1100 m above sea level, and ambient temperatures reaching +40ºC in summer and below -30ºC in winter. At full capacity, the ore concentrate production is expected to reach 170.000 tonnes per day.
When fully expanded, the ore concentrator will include several SAG (Semi-Autogenous Grinding) mills, each rated at 20 MW, as well as several Ball mills, each rated at 10.8 MW. Fully expanded, the total mine load will exceed 300 MW, fed from a dual circuit 220 kV overhead transmission line, more than 200 km long.
|Controlled voltage:||220 kV|
|SVC rating||100 Mvar inductive to 100 Mvar capacitive, continuously variable|
|Control system||- Three-phase symmetrical voltage control by means of a closed loop voltage regulator;
- In cases of single-phase line faults, a negative-phase sequence voltage control is activated
|Thyristor valves||PCT (Phase Control Thyristors) water cooled, indirect light firing|