A Static Var Compensator (SVC) rated at 0-120 Mvar (capacitive) and supplied by Hitachi Energy has been in operation since 1997 at Marcial Ucin´s steel making plant Aciérie de l´Atlantique (ADA) at Bayonne in France.
The purpose of the compensator is mitigation of flicker caused by the operating of a 123 MV A electric arc furnace (EAF) as well as a 25 MV A ladle fur nace (LF), as well as dynamic power factor correction of the plant.
Due to a relatively low fault level of the supplying grid at the point of common coupling (P.C.C.) compared to the size of the EAF, the flicker situation is sever e, with an estimated uncompensated flicker severity reaching Pst(95) = 4. This has called for a solution with an SVC operating in conjunction with a saturable reactor in series with the EAF. The SVC, with its continuously variable compensation, also safeguar ds the plant against overcompensation during fur nace outages.
Flicker, the random variations in light intensity from incandescent lamps caused by the operating of nearby fluctuating loads on the common electric power supply grid, is highly irritating for those afflicted. The random voltage variations giving rise to it can also be disturbing to other process equipment fed from the same grid. The proper mitigation of flicker is therefore a matter of power quality improvement as well as an improvement to human environment.
| Main data | |
|---|---|
| System | SVC |
| Commissioning year | 1997 |
| Controlled voltage | 32 kV |
| Dynamic range | 0-120 Mvar capacitive |
| Control system | Phase-wise reactive power control by means of fast-acting open-loop controller, plus three-phase closed-loop power factor control. |
| Thyristor valve | Three-phase, water-cooled valve with indirect light firing. |