Simulator Based Design of Secondary Cooling Zone Control in Continuous Casting

Abstract

The objectives of secondary cooling zone control in continuous casting are (i) to achieve a suitable profile of strand temperature for a given casting speed and (ii) to suppress its deviation when casting speed changes due to a temporal operation. This paper presents a simulator based design of the cooling zone control which employs both static and dynamic compensators. A simulator of continuous casting process is developed, which enables us to quantify transient and steady state behaviors of the strand temperature. With the help of this simulator, a static nonlinear compensator for (i) is determined via a nonlinear optimization technique. Then, a dynamic simulation with the compensator is performed for a casting speed change, which gives a linear parameter varying (LPV) model that describes the transient behavior. Based on the model, a dynamic LPV compensator for (ii) is derived via an exact model matching technique. Simulation results show that a desirable strand temperature profile is obtained by the static nonlinear and the dynamic LPV compensators even when casting speed changes.