Research On Parameter Identification Method Of Permanent Magnet Synchronous Motor Based On Dixon Criterion

Permanent magnet synchronous motor(PMSM)has the remarkable characteristics of high efficiency,simple structure,high reliability and power density.Under the background of energy saving and emission reduction,PMSM has been widely used in electric vehicles,ship driving and rail transit.With the continuous expansion of the application scope of PMSM,the performance requirements of PMSM control system become higher and higher in many applications.At present,vector control technology with the advantages of high control accuracy and good dynamic performance is the most widely used in PMSM control.Vector control system is based on the accurate mathematical model of motor,which is highly dependent on the motor parameters,and accurate motor parameters are the basis of achieving good vector control.Therefore,it is important to identify and obtain the initial parameters of the motor.In this paper,the offline identification algorithm of each parameter is studied.In order to avoid the influence of unknown deviation of single identification result and considering the limitation of identification times in practical identification,a parameter identification algorithm is designed based on off-line identification,and the effectiveness of the algorithm is demonstrated by experiments.The main contents of this paper are as follows:1.The physical model of PMSM is studied.The coordinate transformation principle and the mathematical model of PMSM in different coordinate systems are analyzed,and the simplified equivalent mathematical model is obtained.Finally,the importance of motor parameters is analyzed through motor mathematical model and vector control.2.The off-line identification algorithms of rotor zero position,stator resistance,d-q axis inductance and rotor flux are studied in detail.Among them,the identification algorithm of rotor zero position is improved,and the influence on voltage and motor torque caused by deviation of identification results based on off-line identification algorithm of each parameter is emphatically analyzed.Finally,in order to avoid the influence of unknown deviation of single identification results,and considering the limitation of identification times in practical engineering applications,a general parameter identification algorithm is designed.3.In order to obtain accurate and reliable parameter identification value,this paper designs a parameter identification algorithm based on Dixon criterion on the basis of the theory of the arithmetic mean value of multiple parameter identification values as the parameter unbiased estimation.Dixon criterion is used to test the anomalous data in the identification data,and then the stable trend of the identification mean is judged.It is decided whether to stop or continue the identification until the identification result is stable after the test.Finally,the validity of the algorithm is verified by simulation.Finally,according to the parameter identification algorithm designed in this paper,the parameters of the motor are identified.The validity of the algorithm is illustrated by the identification times of each parameter and the accuracy of the identification results.