Compound Intelligent Control And Decoupling Technology In The Application Of The Electric Arc Furnace Electrode Adjustment

In recent years, the electric arc furnace steelmaking has developed rapidly and become one of the main way of steelmaking. EAF steelmaking in starts late in China. Although technology has improved, but compared with some developed countries, the scale of electric arc furnace steelmaking in our country is small, the control technology is laggard, the electrode loss is big, waste utilization rate is low, power consumption is large, smelting period is long, product quality is low, and already can’t meet the demand of modern production. Therefore, it has a great significance of improving the level of EAF steelmaking technology to promote the sustainable development of iron and steel industry in China.In electric arc furnace smelting process, the electrode adjustment control system is an important link in EAF steelmaking, its effect is to adjust mobile location of electrodes in the furnace and keep the arc length and the proportion of arc voltage and current constant, so that the input power is stable. Because the electric arc furnace electrode adjustment control system is a nonlinear, strong coupling, multivariable time-varying systems, the conventional PID or single control mode can not meet the control requirements, so a kind of integration, compound intelligent control strategies is needed to design to solve the increasingly complex control system.First of all, based on the full understanding of the working principle of electric arc furnace and smelting technology, establishes three-phase electrode model, ac arc model, power supply system model and hydraulic system model, and analyzes the function relation between electrode arc length and the arc current and arc voltage.Secondly, in view of the three-phase coupling problem between the electrodes, combined with the traditional decoupling method, designs a kind of adaptive decoupling controller based on single neuron, which add decoupling compensator between the controller and the controlled object. It reduces the coupling effect between three-phase electrode. The simulation results show that this decoupling compensation apparatus has good decoupling ability and anti-jamming performance.Finally, according to the electric arc furnace smelting process characteristics and different periods of requirements, control the melting period and redox period by stages. In melting period, furnace charge combustion instability, the system is in disturbance of acute, and arc length change frequently, need electrode regulating system to the rise and fall of the electrode rapidly and accurately. Therefore, designs a PID controller based on BP neural network; in redox period, arc is stable, disturbance is less, hopes to have a higher control precision. So adopt the fuzzy PID control scheme. The simulation results show that the composite intelligent controller can meet the performance requirements in all stages of smelting electric arc furnace.