Control method for the meniscus of a continuous casting mold

摘要

The inflow of liquid metal into a continuous casting mold is set by a closure device. A measured actual meniscus value is fed to a controller determining a closure device target position on the basis of the actual and a corresponding target value. The measured actual value is fed to a disturbance variable compensator. The target position/corrected target position or a corresponding actual value are further fed to the disturbance variable compensator which determines the disturbance variable compensation value. The disturbance variable compensator has a model of the continuous casting mold for determining an expected value. A number of oscillating compensators determine a frequency disturbance proportion. The sum of the frequency disturbance proportions corresponds to the disturbance variable compensation value. The disturbance variable compensator has a jump determiner, by which it determines the jump compensation value by integrating the difference.

主权项

1. A control method for the meniscus of a continuous casting mold, comprising
setting the inflow of liquid metal into the continuous casting mold by means of a closure device and withdrawing the partially solidified metal strand from the continuous casting mold by means of a withdrawal device, feeding a measured actual value of the meniscus to a meniscus controller, which determines a target position for the closure device on the basis of the actual value and a corresponding target value, feeding the measured actual value of the meniscus to a disturbance variable compensator, feeding the target position for the closure device, a target position for the closure device corrected by a disturbance variable compensation value, an actual position of the closure device or an actual position of the closure device corrected by the disturbance variable compensation value to the disturbance variable compensator, determining by the disturbance variable compensator the disturbance variable compensation value on the basis of values fed to it, feeding the target position corrected by the disturbance variable compensation value to the closure device, wherein the disturbance variable compensator comprises a model of the continuous casting mold, by means of which the disturbance variable compensator determines an expected value for the meniscus on the basis of a model input value, wherein the disturbance variable compensator comprises a number of oscillating compensators, by means of which the disturbance variable compensator determines an interference frequency component on the basis of a difference between the actual value and the expected value each relative to a related interference frequency, wherein the sum of the interference frequency components corresponds to the disturbance variable compensation value, wherein the model input value is determined by the relationship
i =p′+z′ wherein p′ is the uncorrected target or actual position of the closure device and z′ is a jump compensation value, and wherein the disturbance variable compensator comprises a jump determiner, by means of which the disturbance variable compensator determines the jump compensation value by integrating the difference between actual value and expected value.