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

The mold is a key facility in the production of continuous casting. Currently, thesystem of electro-hydraulic servo drive is mainly used in the implementation ofcontinuous casting mold non-sinusoidal oscillation, while the system is complicated instructure, high cost of investment and maintenance, existing oil spilling and zero driftphenomena. In this paper, choose the non-sinusoidal oscillation control system ofcontinuous casting mold driven by permanent magnet synchronous motor (a commonlyused servo motor) as research object, on the basis of the requirements of continuouscasting mold before start up and normal oscillation process for motor position control andspeed control, algorithms of position and speed control have been proposed in this paperwith adequate simulation and experiment researches.Firstly, based on vector control theory and coordinate transformation theory,mathematical model of permanent magnet synchronous motor in two-phase rotating dqcoordinate system is deduced, which provides enough theories for its accurate control.Secondly, according to the requirement of fixed position for mold oscillation system,researched the position control method of permanent magnet synchronous motor, aposition tracking control algorithm based on hybrid nonsingular terminal sliding mode andintegral sliding mode is proposed. The sliding mode in the design of the controller isdivided into two parts for the speed and position control, one is the hybrid nonsingularterminal sliding mode used in speed control section to improve its response, while theother is integral sliding mode surface used in position control section to eliminate thesteady state error of the system. By choosing appropriate reaching law, the chattering ofthe system is effectively restrained. The results of simulation are presented to demonstratethe effectiveness of the proposed approach.Thirdly, according to the continuous casting mold requirements for dynamic trackingrapidity and robustness performance of the motor speed system in the normal oscillation,the exponent reaching law is introduced into the motor speed controller design. Furthermore, the fuzzy control method is used to improve the sliding reaching law, and applied to the motor speed control system design, which can improve the performance of slidingmode reaching process, make the controller have same advantages of the sliding modecontrol and also overcome the chattering phenomena in the system. The effectiveness ofthe designed method is proved by simulation results.Finally, the experiment platform of continuous casting mold oscillation controlsystem driven by servo motor is build, the hardware configuration, network configurationand programming of the control system are carried out by STEP7software, and then theexperiments of motor speed control was proceed in the continuous casting moldoscillation system. The experiment results show that the tracking precision is higher, and itlaid a good foundation to realize the non-sinusoidal or sinusoidal oscillation of thecontinuous casting mold.