Since 2002, Cascade Steel in McMinnville, Oregon, USA has been operating an Hitachi Energy Static Var Compensator (SVC) in its Electric Arc Furnace (EAF) based melt shop. The SVC was installed for a dual purpose.
Firstly, the plant wished to run its EAF at a higher power output without risking to infringe on the flicker requirements of the 230 kV power supplier, Bonneville Power Administration (BPA). This would enable an increase of EAF power from 65 MW up to 84 MW, the maximum yield of the furnace in question.
Secondly, the plant wished to lower the overall impact of flicker and harmonics on the transmission supply system, while obtaining an improved power factor at the 230 kV Point of Common Coupling (PCC).
The SVC is rated at 34.5 kV, 0-90 Mvar (capacitive), continuously variable. It has the following tasks:
- Keep a high and stable power factor at the PCC, independently of the reactive power fluctuations from the furnace load.
- Reduce the flicker at the 230 kV PCC to acceptable levels.
- Mitigate the harmonic distortion generated by the furnace.
- Stabilize the system voltage at the 34.5 kV furnace bus.
| Main data | |
|---|---|
| System | SVC |
| Commissioning year | 2000 |
| Controlled voltage | 34.5 kV |
| SVC rating | 0-90 Mvar capacitive
|
| Control system | Phasewise, open loop susceptance regulator |
| Thyristor valve | BCT equipped, water cooled, with indirect light firing. |