Synchronous Control Of Double Permanent Magnet Synchronous Machine Based On Model Prediction

In recent years,due to the requirements for processing accuracy of large parts gradually improve,so large mobile gantry processing center needs to have high precision and high-speed performance,but there are still many technical problems in large mobile gantry processing center,the key is to achieve synchronous control of large mobile gantry processing center double permanent magnet synchronous motor under the premise of high speed and high precision.The main research object of this thesis is the synchronous control system of dual permanent magnet synchronous motor of large mobile gantry machining center.The control algorithm is studied and improved.The main research contents include:(1)In terms of uniaxial control strategy,improved model prediction(MPC)control strategy is adopted in this thesis to realize position control of permanent magnet synchronous motor.The position loop of permanent magnet synchronous motor is controlled by PI,and the speed loop is controlled by model predictive control based on Romberg observer.Finally,the beat free model predictive control and direct predictive control are respectively applied to the current loop,so as to form a three-closed loop servo control system.The model predictive control is based on the predictive model of the controlled object,and adopts the optimal performance index and feedback correction strategy to make the permanent magnet synchronous motor have better control performance in dynamic response and load disturbance resistance.(2)In terms of synchronous control strategy,because the higher the coupling coefficient in cross-coupled control,the more unstable the system is,the traditional cross-coupled control is improved,and a cross-coupled control based on fuzzy PID control is proposed.PID compensator is used to solve the problem of synchronous speed deviation caused by disturbance of two motors.In this thesis,the advantages of the model predictive control dynamic processing multivariable system are combined with the improved cross-coupling controller,and applied to the synchronous control system of dual permanent magnet synchronous motor.The influence of uncertain factors such as position error,speed error and external disturbance in the control system is overcome,and the position synchronization error between the two axes is further reduced,and the position and speed tracking ability is strong.The control system has high control precision and fast response,which can compensate the system and reduce the synchronization error in time,and effectively improve the synchronization performance of the system.The simulation results show that this control scheme is robust,dynamic process synchronization error is small,and can better meet the requirements of the controlled object for high speed and high precision.