Strongly Nonlinear Dynamics of Torsional Vibration for Rolling Mill's Electromechanical Coupling System

The torsional vibration often occurs during the rolling process, which will affect the production equipment. Based on electromagnetic field theory, the air gap magnetic field energy of salient pole synchronous motor was given, and the expression of electromagnetic torque was derived using the energy analysis method. In order to study the electromechanical coupling characteristics of the main drive system in rolling mill, a torsional vibration model with strongly nonlinear terms was established on the basis of mechanical dynamic principle. The periodic solutions of the strongly nonlinear torsional vibration system were obtained using the incremental harmonic balance (IHB) method. When the excitation force amplitude and the electromagnetic stiffness changed, the influence law on the torsional vibration characteristics of electromechanical coupling system under strongly nonlinear conditions was found. The effects of different electrical and mechanical parameters on the system amplitude-frequency property and vibration displacement characteristics were analyzed. All these research results are significant to structure design, parameter optimization and vibration control for the mill drive system.