Simulation Research On Permanent Magnet Synchronous Motor Control System Based On MPDTC

With the development of power electronics technology and computer technology,the advantages of permanent magnet synchronous motors have become more prominent,and they are widely used in applications with high reliability requirements due to their small size,light weight and high efficiency.Direct torque control is a simple and easy to implement,fast torque response and robust control method,which has been widely used in permanent magnet synchronous motor control.However,due to the unstable switching frequency in direct torque control,there are problems such as asymmetry of flux linkage and large torque ripple.Therefore,this paper takes the permanent magnet synchronous motor direct torque control system as the object and does the following work:(1)Considering that PI is sensitive to parameters,the speed error is used as the state quantity,the fast terminal sliding mode function and the exponential approach rate are selected,the speed controller based on fast terminal sliding mode is designed,and the convergence proof and stability analysis are given.Finally,The quasi-sliding mode function sigmoid(s)replaces the sign function to reduce chattering.Simulation experiments show that the improved speed fluctuation is reduced from 10‰ to 1‰ of the original system,and the speed response is accelerated.The torque ripple is improved from 3.7592 to 2.4120,which is 35% lower than the original system.The verification algorithm is effective and feasible.(2)Aiming at the problems caused by mechanical sensors,a sensorless filtering algorithm based on adaptive unscented Kalman is introduced.The iterative formula of the permanent magnet synchronous motor based on the adaptive unscented Kalman filter algorithm is derived and implemented in the simulation platform.Simulation experiments show that after introducing the adaptive unscented Kalman filter algorithm,the torque ripple is reduced from 2.4120 to 1.8304,and the torque ripple is further improved by 24.1%,which is 51.3% better than the traditional direct torque control system.The unscented Kalman filter algorithm is effective for improving the torque ripple.(3)To further reduce torque ripple to meet high-precision applications,model predictive control is introduced.A large-scale and simplified prediction model is predicted for the traditional model,and a model prediction algorithm considering the duty cycle is designed on the simplified model.The mathematical model of the algorithm is given.The simulation experimental data shows that after introducing the simplified duty cycle model predictive control,the torque ripple is reduced to 0.9306,which is 48.1% better than before the introduction,and the torque ripple is improved by 74.7% compared with the traditional direct torque control system.