In 2009, an SVC supplied by Hitachi Energy was commissioned in the LKAB iron ore mine at Kirunavaara in the north of Sweden. The SVC, rated at 0-35 Mvar at 6.3 kV, has the purpose of improving power quality at the 145 kV Point of Common Coupling (PCC) as well as inside the mine by reducing voltage fluctuations and harmonics. As a direct benefit, with the SVC in operation, the ore hoisting capacity has risen, as well, making the extracting process more efficient than before.
In the demanding environment of an iron ore mine, special focus was given to creeping distances of support insulators of outdoor equipment due to iron dust. Likewise, as the mine is situated north of the Arctic Circle, focus was given to snow clearance in winter time, as well as surrounding temperatures down to -50 C.
| Main data | |
|---|---|
| System | SVC |
| Commissioning year | 2009 |
| Controlled voltage | 6.3 kV |
| Dynamic rating | 0-35 Mvar (capacitive) |
| Harmonic filters | 5th harmonic / 10 Mvar 7th harmonic / 5 Mvar 12th harmonic / 20 Mvar |
| Control system | - Closed loop control, based on power factor control, Mvar control or voltage control on the 6.3 kV bus; - Open loop reactive power control |
| Thyristor valve | Water cooled, PCT type thyristors, indirect light firing |
