Research On Oscillation Control System Of Continuous Casting Mold Driven By Permanent Magnet Synchronous Motor

Continuous casting mold is the core equipment of the continuous caster. The moldoscillation in non-sinusoidal law can improve casting speed and the quality of slabdramaticlly. The performance of its oscillation mechanism plays a very important role inimproving the productivity of the continuous casting machine. In this paper, by taking thenon-sinusoidal oscillation mechanism of continuous casting mold driven by PMSM(acommonly used servo motor) as the research object, the accurate control of speed andposition of PMSM and the concrete realization of the vibration control system are studied.Firstly, the mathematical model and the vector control method of PMSM are given,which provide sufficient theoretical basis for the analysis of the motion laws and theresearch about the efficient control strategies of PMSM.Secondly, based on the requirement of the high precision speed tracking control of thesystem of continuous casting mold oscillation driven by PMSM, the method of adaptivefuzzy terminal sliding mode control is proposed. The speed controller is designed by usingthe non-singular terminal sliding mode and reaching law. The proposed scheme canattenuate chattering of control output and improve the convergence speed and trackingaccuracy of the system. Adaptive fuzzy algorithm is used to approximate unknownfunction with load torque, which can improve the ability of system to resist loaddisturbance.Thirdly, according to oscillation control system requirement on the mold positioningcontrol, the position control of permanent magnet synchronous motor is studied, and abackstepping terminal sliding mode control algorithm based on load observer is proposed.The controller is designed by using the backstepping based on non-singular terminalsliding mode replaced the common sliding mode in traditional backstepping sliding mode.And the proposed scheme can enhance response speed of the system. At the same time,terminal sliding mode control is introduced to design observer of load torque. And thisachieves to evaluate load torque quickly and accurately, which enhances the robustness ofsystem. Finally, the hardware and software are designed for the control system of continuouscasting mold oscillation driven by PMSM, and part experimental studies has been carriedout under the existing conditions in the laboratory. The experimental results show thatPMSM can accurately track different given signal of speed, which demonstrates thefeasibility of the designed control system and lay a good foundation for the application ofPMSM in the continuous casting mold oscillation system.