Bifurcation and chaos for electromechanical coupling torsional vibration in rolling mill system driven by DC motor

Abstract

Bifurcation and chaos for electromechanical coupling torsional vibration in rolling mill system driven by DC motor is studied in this paper. Considering the electromechanical devices under unsaturated magnetic circuit, the dynamical equation of electromechanical coupling vibration in rolling mill drive system is deduced by using the dissipation Lagrange equation. The equivalent low-dimensional bifurcation equation, which can reveal the influence of system parameters on the nonlinear dynamic characteristics, is obtained by reducing the dimensionality system using the method of Lyapunov-Schmidt reduction, and the static bifurcation characteristic is analyzed by using the singularity theory. The torsional rigidity of rotating shaft and harmonic excitation are chosen as the bifurcation parameters. Finally, the simulation is carried out with actual parameters, the bifurcation diagram, Poincare map and the maximum Lyapunov exponent are also given, which show the influence of bifurcation parameters on the chaotic motions of the system.

Influence Factors of Inherent Characteristics of F5 Cold-Rolling Mill’s Main Drive System

“…Liu et al [12][13][14][15] established a strong nonlinear electromechanical coupled torsional vibration model based on a salient-pole synchronous motor and DC motor and analyzed the influence of electrical and mechanical parameters on the rolling mill torsional vibration. Liu et al [16] established a rolling millelectric coupling torsional vibration model driven by a DC motor and studied the bifurcation and chaotic phenomena of the system. Zhang et al [17,18] established a nonlinear model of rolling mill-electric coupling based on AC motor and studied the influence of the rotor induced current and electrical parameters on the torsional vibration of the main drive system.…”