Model Identification for the Mould Level Control Loop in a Continuous Casting Machine

Abstract

One of the main parameters affecting the surface quality of the slabs in a steel factory is the mould level control for a continuous casting machine. The key problem is that the parameters of the flow control system with, its mechanical and electrical components are tlme-varying and nonlinear under the conditions of high temperature and cont1nuous casting. In SIDMAR Steel Company in Belgium, a set of measurement instruments were installed in the continuous casting machine type CONCAST 2400/230 10.5/3R. In the first stage, the identified results showed that the hydraulic system was a nonlinear but stable system, and, furthermore, that the larger the peak-to-peak value of the input signal, the higher the natural frequency of the closed-loop hydraulic system. In the second stage, a series of linear models of the components of the level control loop corresponding to various operating conditions were established. These will be used to build a computer simulation of the process. In a later stage, the parformences of. different self-adaptive predictive control methods combilned with on-line parameter identification will be simulated, and investigated. The strong points and the short-comings of the original PI dlg1tal controller and the different. self-adaptive pred1ctlve control methods will be compared.