The article is concerned with the advanced automatic control system of electrode positioning at electric arc steel making furnaces and ladle furnaces. Analysis of structure of modern electrode positioning control systems’ nonlinear controllers for electric arc furnaces and ladle furnaces is considered. Disadvantages of these systems were analyzed. A control system with a conventional structure from well-established foreign suppliers was compared with the advanced automatic control system of electrode positioning.

The article deals with the description of an improved automatic control system for steel-making furnaces (electric arc furnaces and ladle furnaces) electrode positioning and the results of its production testing. The control performance of electrode positioning of the developed automatic control system was studied using a mathematical model, which included the main components of the system: the hydraulic drive of electrode positioning with a servo valve, electric circuit of the furnace described by Cassie nonlinear differential equation, impedance nonlinear controller. It was proved that a more accurate positioning makes it possible to significantly reduce electric power consumption per tap-to-tap cycle.

Requirements on the systems controlling the electrical conditions of superpowerful arc furnaces in steel smelting are outlined. The basic principles for electrical optimization at different phases of smelting are considered. An improved mathematical model is proposed for analysis of the arc furnace's electrical char acteristics and the dynamics of the automatic control system governing electrode motion. A diagnostic system capable of identifying the phase of smelting on the basis of the harmonics of the arc currents shortens the fur nace's working cycle and reduces the power consumption.