Analysis of power quality for active power stabilization of electric arc furnace by means of static VAR compensator

The paper presents the key findings of studying the quality of electricity at the buses of an electric steel-making complex as affected by a static var compensator (SVC) running a novel control algorithm designed to improve the electric performance of an electric arc furnace (EAF) by stabilizing its active power at an optimal value. Analysis of how an SVC runs this algorithm reveals a considerable degradation of voltage quality compared to experiments with conventional algorithms. For detailed evaluation of SVC effects on the quality of electricity (QE), the research team ran an SVC in active-power mode and computed the QE values characterizing slow voltage deviations, non-sinusoidality, imbalance, and fluctuation; the values were compared against those attained by the reactive power- or voltage-controlled compensator. Experimentation used the mathematical model of an existing EAF-120-SVC unit, which was developed and run in MATLAB Simulink. To enable the SVC to sustain a constant active EAF power while also keeping the QE values sufficiently high, the paper proposes a structure of additional voltage and reactive power coefficient constraints, voltage balancing, and flicker suppression.