Research On Parameter Identification Of Permanent Magnet Synchronous Motor Based On Inverter Nonlinear Compensation

Due to the advantages of simple structure,small size,low loss,high operating efficiency and abundant rare earth resources,the permanent magnet synchronous motor(PMSM)is application more and more extensive.This dissertation use vector control technology to realize high performance speed regulation of the surface attached permanent magnet synchronous motor(abbreviation motor).High dynamic performance PMSM speed control system needs to build an accurate dynamic mathematical model,and the accurate dynamic mathematical model must obtain accurate motor parameters with real-time,thus ensuring the PI parameters of the control system,the speed of observer observation the accuracy of the speed and rotor angle,so as to obtain excellent static and dynamic characteristics.The parameters of the motor are identified with real-time and accurately is the premise and foundation for obtaining high performance speed regulation.,it has the important theoretical and practical significance.In this dissertation,PMSM is taken as the research object and the stator resistance,the direct-axis inductance and the permanent magnet flux linkage are mainly identified.By analyzing the factors that affect the motor parameters and the influence of parameter changes on the control system,the parameter identification algorithm of PMSM is studied.Parameter identification methods include off-line identification and on-line identification.The off-line identification is the common method to identify the motor parameters at present.The DC volt-ampere method is usually used to identify the motor stator resistance,and high-frequency injection method and pulse voltage method are used to identify stator inductance of PMSM.Online identification is the development trend of motor parameter identification,it requires accurate input and output information.This dissertation combines the recursive least square algorithm(RLS)with the model reference adaptive system(MRAS),which not only improves the accuracy of parameter identification and identification speed,but also avoids the shortcomings of the low identification precision of the recursive least square algorithm and the slow identification of the model reference adaptive system.In vector control,the inverter has nonlinear characteristics,and its influence on the switching time of the switch tube and the output voltage and current of the inverter is analyzed.The inverter nonlinear compensator is designed based on the disturbance observer.The simulation results show that the compensator can effectively suppress the influence of inverter nonlinearity on the voltage and current of the motor.In addition,the causes of parameter identification accuracy and dynamic stability are analyzed,and a compensator module is added in the parameter identification simulation.The simulation experiment results show that the compensator can effectively compensate for the precision error and dynamic oscillation caused by the nonlinearity.