Simulation model of PI controller for the header flux control of ultra-fast cooling in hot strip mill

Parameters optimization of the PI controller was investigated for the header flux control of Ultra-fast cooling. Taking the measured curve, Ultra-fast cooling (UFC) header flux under different open rate of valve, as the input parameters, a simulation model was developed. Based on the coupling control of proportion(P) and integration(I), the parameters with minimum root-mean-square-error of header flux was considered as the best. The simulation results showed that the optimal integration time was 600ms under industrial conditions. Furthermore, the correction equations for the P and I controller were established by the newly developed simulation model. The results from the on-site implementation indicated that the flux deviation between target and measured values was less than ±l.0m3/h during the constant operation of the UFC header, and the overshoot value was within 3.0m3/h of the apparent interference.