Flicker control for electric arc furnace

A method of operating an electric arc furnace, the method comprising:

• receiving indications of a plurality of operating variables of the electric arc furnace, wherein the operating variables include a flicker of a power grid supplying the electric arc furnace;
• receiving indications of firing angles of a plurality of thyristor switches in a variable reactance device controlled by the plurality of thyristor switches, the variable reactance device having a control range;
• predicting a power grid flicker based upon:
• the received indications of the plurality of operating variables;
• the received indications of the firing angles of the plurality of thyristor switches;
• and
• the control range of the variable reactance device;
• determining that the predicted power grid flicker is a power grid flicker excursion, wherein the predicted power grid flicker exceeds a predefined threshold, based on:
• determining that at least one of the received indications of the firing angles of the plurality of thyristor switches is at one of:
• at or above a firing angle upper excursion likelihood threshold, or at or below a firing angle lower excursion likelihood threshold;
• determining, upon receiving an indication of the predicted power grid flicker excursion, an adjustment to at least one operating variable among the plurality of operating variables;
• and
• transmitting, to a controller of the at least one operating variable, instructions to adjust the at least one operating variable such that the predicted power grid flicker remains below the predefined threshold, with effect that the predicted power grid flicker excursion is avoided.