Predictive Control For The Electrode Regulating System Of Electric Arc Furnace

As the performance of the electrode regulating system of electric arc furnace (EAF) directly effects the utilization of energy, labor productivity and consumption of the EAF, it is critical to have a strict demanding. For rapidity and sensitivity, scientists continue working hard and applying new methods and theories to the electrode regulating system.Based on a great deal of documents related with the EAF, the thesis summarizes a brief introduction about the current situation and the tendency of development of steel-making process with EAF both at home and abroad. Starting from the energy conservation law, and according to the characteristics of the production process of EAF, a time-domain model of the electric arc which is described with nonlinear differential equations is established. The model can reflect the microcosmic properties of the electric arc, and can also reflect the time-varying characteristics at different production stages well. After analyzing the mechanism of electrode regulating system, the mathematical models of electrical system and hydraulic system are established.Aim at the nonlinear and time-varying characteristics of EAF, the thesis designs a electrode controller with the multi-layer recursive adaptive predictive control method which is suitable to the nonlinear and time-varying system. Nonlinear system is substituted with a time-varying linear system, and multi-layer recursive method is used to identify and to forecast the varied parameters in order to get the predictive output of system model. At last, adaptive predictive control is designed for the original nonlinear system.At last, the thesis simulates the electrode regulating system of the EAF with the MATLAB software. Through the comparison of the conventional PID and multi-layer recursive adaptive predictive controller, the results show that the multi-layer recursive adaptive predictive controller is an effective solution for the electrode regulating system, and the control has achieved the desired results.