Optimal control of static VAr compensators in power supply systems with electrical arc furnaces

Electrical arc furnaces (EAF) with power ratings of, in-part, far more than 100 MVA, cause voltage fluctuations and flicker in the supplying power system. Static VAr Compensators (SVC) are typically used for reactive power compensation. This paper presents a solution for how to obtain an optimum flicker reduction at a comparatively low compensator power rating by an anti-windup extension of the controller. Based on an example of dimensioning a SVC for a steel plant grid with high-power AC EAF savings amounting to approx. 2.1 M US$ can be realised by implementing the proposed amendments to the compensator control. The researched compensator solution represents an optimum from the technical as well as from the economic point of view.