Research On Coupling Vibration Of Main Drive System Of CSP Mill By Multi-source Harmonics

For decades, the vibration of a rolling mill is always the problems of the impact of production stability and quality. With the development of modern tandem mill equipment and technology, the phenomena and properties of vibration are showing more complexer than in the past. In this paper, the main drive torsional vibration of CSP hot rolling mill driven by cycloconverter is taken as research object. Through field testing, the rich coupled vibration phenomenon are found during mill rolling. The in-depth study of mechanism of coupling vibration for hot rolling mill is maked by theoretical analysis, numerical simulation and experimental validation,then the vibration suppression measures are proposed. The main results of this work and research show as following:(1) Using homemade online monitoring system to test the coupling vibration of the hot rolling mill synthetically, the vibration behavior and characteristic are obtained under different conditions. Experiments show that the complex coupled vibration behavior and harmonic phenomenon exist when mill rollling thin gauge strip, which provide data to support the theory and facts for study the mechanism of coupling vibration of mill.(2) Combined with the composition of hot rolling mill equipment, the analytical model of cycloconverter, synchronous motors, main drive system and rolling load are analysed theoretically, and the correlated coupling variables of each unit are got, then the theoretical model is determined, which illustrate that power harmonics couple with rolls system through mian drive system and deformation zone.(3) Combined with Matlab/Simulink and ANSYS, the coupling mechanism of cycloconverter harmonics, load harmonic and transmission machinery are studied respectively. It is supposed that torsional vibration of main drive system is the coupling vibration behavior under the comprehensive influence of power energy source, load disturbance source and mechanical transmission(energy transfer source). Experimental verification has been make for related research.(4) According to multi-dimensional linear models and equivalent model including nonlinear stiffness and damping, respectively; the mechanical transmission is excited by power harmonics and load harmonics under conditions of steady-state load, then torsional vibration characteristics of main drive system are solved theoretically and studied by simulation.The results show that the main drive system presente polymorphic coupling features under the excitation of multi-source harmonics.(5) Base on the field test, theoretical research and simulation analysis, the vibration suppression measures are proposed. The theoretical simulation and field application experiments are implemented for suppression of power quality harmonics, load torque disturbance and the change of transmission structure parameters, then good consequences are achieved.