Research On Model Predictive Control Of Permanent Magnet Synchronous Motor Speed Control System

With the permanent magnet heat resistance,corrosion resistance continues to increase,the price is increasingly low.These advantages make the permanent magnet synchronous motor(PMSM)relatively simple and more efficient than other motor structures,and has become a hot topic in domestic and foreign research and has been widely used in many occasions.Model Predictive Control(MPC)is a nonlinear computer control theory.Compared with other control methods,the Model Predictive Control has the advantages of fast dynamic response,strong multi-objective optimization and flexible implementation,and has strong industrial application background.The model predictive control calculates the effect of the control quantity on the future time and corrects the feedback to reduce the error.It is also important to study the model of predictive control of permanent magnet synchronous motor(PMSM),which can improve the energy utilization rate of motor.It is of great significance to study the effect of model predictive control on permanent magnet synchronous motor.By studying the structure and classification of permanent magnet synchronous motor,the mathematical model and the discrete mathematical model of the synchronous rotating coordinate system are analyzed in detail.The operation conditions of the permanent magnet synchronous motor,the optimal operation state and the basic structure of the model predictive control algorithm are analyzed in detail.Basic principles,for the full text of the study laid the foundation.Firstly,the cost function and simulation model of traditional model predictive vector control are studied and designed.The limitation of traditional algorithm is analyzed by simulation results.In order to solve the shortcomings of the traditional algorithm,the Maximum Torque Per Ampere(MTPA)algorithm based on direct torque control is adopted.At the same time,the switch state constraint and delay compensation algorithm are added.And the simulation model is established.The comparison between the simulation results and the traditional algorithm shows that the MTPA algorithm has good dynamic and static characteristics.Aiming at the problem that the MTPA control algorithm is limited to the rated speed,field-weakening control algorithm based on direct torque control is designed.Two kinds of optimization modes of maximum voltage and weak magnetic control are added to the cost function and a simulation model is established.The simulation results show that the field-weakening control has good static and dynamic performance,and achieves the expected effect.