Molten steel level controller based on disturbance observer with time-delay compensation

Regulating molten steel level in continuous casting is difficult, because it suffers from various disturbances, among which the bulging disturbance is the most prominent. Moreover, as the casting speed increases in continuous casting, the phase lag due to the system delay increases. In this paper, we propose a disturbance observer with time-delay compensation to eliminate the bulging disturbance in the presence of system delay. We tested the proposed method using a 1 : 1 scale hardware simulator and confirmed that the method successfully decreased the bulging disturbance effect from the molten steel level.