Method of Switching Point Determination for Control System of Electric Arc Furnace Based on Data about Harmonics of Arc Currents and Voltages

The article describes a method of switching point determination for the control system of an electric arc furnace, based on the data about harmonics of arc currents and voltages. Firstly, the measurement data about electric arc current and phase voltage instant values was gained for the calculation of the electric arc voltage signal. Further, the relative values of odd and even harmonics of electric arc current and electric arc voltage were determined through the Fourier transformation in the switching moments of the operating curve and furnace transformer step. The analysis of the resulting values allowed forming the basis for a principally new melting stage profile for the electric mode control system, based on the data about the harmonic composition of electric arc current and electric arc voltage.