Off-line Parameter Identification And Parameter Self-tuning Of Permanent Magnet Synchronous Motor

Permanent magnet synchronous motors(PMSM)are widely used in industrial drives,medical equipment,aerospace,electric vehicles and other fields due to their high efficiency,high power density,small size and good dynamic performance.Because of the lack of self-starting function,the PMSM needs to obtain an accurate initial position of the rotor before starting.In order to improve the control performance of the PMSM and realize the versatility of the motor controller,it is necessary to adjust the controller parameters according to the motor parameters.In this paper,the research works on rotor initial position identification,motor offline parameter identification and controller parameter tuning are as follows:Firstly,a filterless high-frequency pulse signal identification method is proposed to reduce the system bandwidth,observer response speed and system phase offset caused by the filter link.The method uses the response current signals of the straight axis and the cross axis to remove the high frequency signal components,eliminates the influence of the amplitude and frequency of the injected high frequency signal and the phase shift caused by the filtering link on the identification results,and improves the accuracy of rotor position identification.Secondly,an improved magnetic pole polarity identification method is proposed due to the deficiency of traditional method,such as the voltage signal amplitude,the secondary harmonics based method,and the response current amplitude method.The improved method injects a mixed signal of DC bias and high frequency sinus in the forward and reverse directions of the initial identification angle of the rotor position,and uses the magnitude relationship of the two response currents to determine the polarity of the magnetic pole,which can effectively improve the polarity identification accuracy and simplifies the identification process.Thirdly,in order to remove the influence of the nonlinear factors of the inverter on the identification results,the stator resistance identification method based on voltage and current increment ratio is studied.The injected DC bias and high-frequency sinusoidal mixed signals are used to identify the equivalent inductance,which effectively improves the identification accuracy.The controller parameters is turned by using the off-line parameters obtained by identification.Finally,the proposed filterless high-frequency pulse signal method for identifying rotor position and improved magnetic pole polarity identification method is verified by 16 kW permanent magnet synchronous motor vector control platform.At the same time,the experimental results proved that the parameter tuned based on the identified stator resistance and inductance parameters can meet the system response speed and steady-state accuracy requirements.