The problem
The feeding grid at the Uddeholm Tooling steelworks in Sweden, with its metallurgy based on scrap melting and subsequent refining, is relatively weak with a fault level at the point of common coupling (p.c.c.) of about 1000 MVA. It became obvious that this was insufficient to enable operation of two large furnaces without generating to high levels of light flicker.
The solution
Uddeholm Tooling turned to ABB to provide an efficient countermeasure to the flicker problem, in the form of an SVC Light. The possibility for the SVC Light to “track” the stochastically varying furnace current gives it a truly unequalled capability to reduce voltage flicker. The SVC Light is rated at 0 - 44 MVAR of reactive power generation, continuously variable. This dynamic range is attained by means of a VSC rated at 22 MVA in parallel with two harmonic filters
The SVC Light, taken in service in 1999 is additionally used to improve the power factor and stabilize the bus voltages in the steel plant, showing its strength as a true FACTS device. This ensures minimized billing for reactive power as well as a capitalization by means of increased furnace productivity as well as lower specific production costs (electrode consumption is reduced).