Robust set-point controllers for an electric arc furnace cooling system

A Lyapunov-based robust control approach is considered for set-point control of an electric arc furnace cooling system, with significant uncertainty, and which is subjected to a measurable input disturbance. In particular, stabilisation and synthesis of robust controls are investigated. The focus of this work is on the development of a controller that guarantees global asymptotic stability properties of an uncertain bilinear model, and regulates the system output at the desired set point. Simulation results, utilising data from an industrial plant, indicate the potential of such an approach to meet the requirements of the system in terms of set-point control. A characteristic of Lyapunov-based robust controllers is that they often produce a 'chattering' type of control action. To overcome this drawback, a technique is proposed to reduce such chattering. (C) 2004 Elsevier Ltd. All rights reserved.