Design of speed disturbance compensation controller in the secondary cooling zones for billet

Abstract

Combined with the established three-dimensional dynamic solidification heat transfer model, a feed-forward controller under speed disturbance was designed for compensating secondary water. In order to improve the control quality of the surface temperature for billet, based on the determination of the transfer function matrix structures of the control channel and the disturbance channel, the heat transfer coefficient and the step changes of cast speed were employed as input activation, the surface temperatures of the casting billet were implied as the output response, and the step response curves and least square method were used to identify the transfer function. The simulation results shows that, the gain of the frequency response curves of the transfer function and the variation between the billet surface temperature and the target temperature are both reduced, and the quality of control is improved.