| With the rapid development of global economy and science and technology,the theories related to motor control have made great progress.Now the domestic and foreign industrial production of the AC motor is also growing enthusiasm,which puts forward more challenges to the optimization of its control strategy.Permanent magnet synchronous motor(PMSM)is popular in various industries because of its high power density,compact structure,excellent dynamic performance and many other advantages.Because the mechanical sensor brings many unfavorable factors to the control system,many researchers at home and abroad take sensorless control as the technical difficulty,and carry on the continuous conquering.The sensorless control technology of IPMSM is studied in this thesis.In this thesis,the structure of PMSM is briefly explained at first,then the Clark and Park transformations are introduced briefly,and then several mathematical models of IPMSM are given.Then several motor control methods are analyzed,their advantages and disadvantages are compared,and two widely used vector control methods are compared and analyzed.Then,aiming at the phenomenon that the back electromotive force of the motor is difficult to obtain in the low speed domain,the rotor position of the motor is calculated by using the high frequency square wave injection method.The simulation results show that the observed data of the high frequency square wave injection is accurate.In this thesis,a hyperbolic tangent variable saturation function is selected to improve the chattering problem of the SMO system.In this thesis,a variable frequency low-pass filter is designed,and the rotor position compensation mechanism is proposed to reduce the system observation error and make the control system more reliable and accurate.In order to improve the control effect of the motor,it is necessary to provide real-time and accurate motor parameters for the control algorithm.In this thesis,MRAS is chosen as another observation algorithm.MRAS has the advantages of simple method,strong practicability and reliable identification for PMSM stator resistance identification,which can meet the required control precision requirements.After analyzing and studying the various characteristics of the propeller,the mathematical model is built,and then the simulation module is built in MATLAB for verification.Then,the propeller module built is used as the load of the motor,and the lowspeed to high-speed operation simulation is carried out for both the no-resistance identification system and the resistance-plus identification system to verify the feasibility and efficiency of the algorithm.The results show that the observation results of the composite observation system with resistance identification are accurate and reliable,and the switching of low and high speed operation is smooth,the speed rises steadily,and the motor runs stably. |
