CONTROL METHOD FOR THE MENISCUS OF A CONTINUOUS CASTING MOLD

摘要

The inflow of liquid metal (3) into a continuous casting mould (1) is set by means of a closure device (4). By means of a withdrawal device (8), the partially solidified metal strand (7) is withdrawn from the continuous casting mold (1). A measured actual value (hG) of the meniscus (9) is fed to a meniscus controller (18), which determines a target position (p*) for the closure device (4) on the basis of the actual value (hG) and a corresponding target value (hG*). The measured actual value (hG) is fed to a disturbance variable compensator (20). The target position (p*) for the closure device (4), or a target position corrected by a disturbance variable compensation value (z), or a corresponding actual value (p) are further fed to the disturbance variable compensator (20). The disturbance variable compensator (20) determines the disturbance variable compensation value (z). The corrected target position is fed to the closure device (4). The disturbance variable compensator (20) comprises a model (21) of the continuous casting mold (1), by means of which it determines an expected value (hE) for the meniscus (9) on the basis of a model input value (i). The disturbance variable compensator (20) further comprises a number of oscillating compensators (23), by means of which a frequency disturbance proportion (zS) is determined on the basis of the difference (e) between the actual value (hG) und the expected value (hE), each relative to a related disturbance frequency (fS). The sum of the frequency disturbance proportions (zS) corresponds to the disturbance variable compensation value (z). The model input value (i) is determined by the relation of i = p'+z', where p□ is the uncorrected target or actual position (p*, p) of the closure device (4) and z□ is a jump compensation value. The disturbance variable compensator (20) comprises a jump determiner (22), by means of which it determines the jump compensation value (z□) by integrating the difference (e).