Phase stability index of AC furnace Arc based on RMS and THD

In this paper, a method to calculate the phase stability index of AC furnace arc is proposed. To find the period of distinguished arc, root mean square (RMS) values of phase voltage and current are used. Also, to detect the distortion of phase voltage and current, total harmonic distortion (THD) are employed. Then, two indices are combined to complement each other. Finally, simulation results verify the performance of the indices.