FLICKER COMPENSATION DEVICE FOR DC ARC FURNACE

摘要

PURPOSE:To reduce a flicker generating quantity by predicting reactive power generated in a DC arc furnace with the use of a phase control angle controlling a DC converter and a DC current, controlling a thyristor based on the reactive power generation predicting quantity and generating the reactive power from a flicker compensation part when the DC converter is controlled. CONSTITUTION:In a phase-control angle control means for DC converter 33, the DC converter 23 is controlled by using the phase-control angle alpha obtained based on the deviation between a detection current from the DC detector 32 and a set current, and a constant current is controlled. At that time, a reactive power generating quantity prediction means 41 fetches the command signal of the phase-control angle alpha and the DC current Id and predicts the reactive power generating quantity of the DC arc furnace 25 by setting a non-load DC voltage E0 to be known. Then, a pulse generated from a pulse generator 42 is made variable based on the reactive power generating quantity predictive value, and the phase-control angle of the thyristor 44 is controlled. Thus, the reactive power can be compensated to the power system with the flicker compensation part 46 simultaneously with the control of the DC converter 23, and the flicker generating quantity can be reduced.