Calculating Simulation Model Parameters for Electromechanical System of Rolling Mill Stand

Abstract

Improving the precision of calculating the model parameters of the rolling stand electromechanical system is a relevant problem. When developing models, such systems are assumed to be two-mass ones with an elastic constraint and angular gaps in the transmitting shaft line (spindle). Applying the technique for calculating the parameters of the “drive-roll” simulation model based on experimentally recorded oscillograms is exemplified by the electric drives of the reversing rolling stand at the plate mill 5000 of PJSC Magnitogorsk Iron and Steel Works. The spindle design has been considered; it is shown that gaps are most frequently formed at the coupling heads on the roll and the engine rotor sides. The drive model structure in a closed-loop speed control system is given. The approximation of the inner motor torque control loop transfer function by a second-order filter is justified. The frequency characteristics of the loop response for the disturbing effect have been studied. The oscillatory nature of the transient torque at the initial control adjustment has been proved. Processes have been simulated for shock loading and different speed control time constants. The optimal time constant variation range ensuring the reduction of oscillations in a closed-loop system is justified. The design transient torque curves are provided for the acceleration and shock loading modes at various angular gaps in the spindle joints. It is shown that at the optimal speed control setting, the angular gap affects the amplitude insignificantly. Recommendations are given for the further application of the research results.