Design of speed robust controller for rolling mill electromechanical drive based on Lyapunov stability theory

Abstract

The drive motor of the rolling mill and the rolling spoke are connected by a long shaft, and the rigidity of the connecting shaft is limited. Therefore, when the strip is rolled at a high speed, the double closed-loop control of conventional current and speed is prone to electromechanical vibration and strip breakage. Robust control performance against load interference poor. In order to overcome this shortcoming, a robust speed controller based on Lyapunov stability theory for the electromechanical drive speed of the rolling mill was designed. The torsional vibration mode of the electromechanical drive system of the rolling mill is established by using the mathematical models such as Kirchhoff’s law, Newton’s second law and the law of the action of the magnetic field on the current-carrying coil. On this basis, a speed robust controller is designed. The controller is the conversion of the symmetric terms of the main diagonal of the matrix. Therefore, considering the fragility of the controller, through the Lyapunov stability theory and the LMI method, the sufficient conditions for the existence of the state feedback controller are obtained. Rod non-brittle controller and feedforward compensator. The simulation research results show that the design in this paper can effectively improve the control performance of the main drive system of the rolling mill, suppress the electromechanical vibration phenomenon of the system, and also has strong robustness to the perturbation of the internal parameters of the system such as the rolling moment of inertia. It has strong effectiveness and superiority to reduce the vibration of support roll and work roll.