Robust molten steel level control for continuous casting

This paper presents a new control method for stabilizing the molten steel level in the molding process of a continuous casting mill. A disturbance observer is employed to estimate a disturbance flow which breaks the equilibrium of mass flow in the mold. Then, the manipulated value is calculated to counterbalance the effect of the estimated disturbance flow. This control scheme enables a straightforward and intuitively comprehensible way of designing and tuning controllers, in addition to high performance. The control method has been successfully applied to the molten level control systems in several continuous casting mills