Static Identification of Inductance Parameters and Initial Rotor Position in Permanent Magnet Synchronous Motor

Accurate determination of inductance parameters and rotor initial position is of paramount importance in ensuring optimal control accuracy and stability in the context of permanent magnet synchronous motors. This paper proposes a novel static identification method for both the inductance parameters and rotor initial position of a permanent magnet synchronous motor, to achieve simultaneous identification of both parameters. The method involves the injection of high-frequency quadrature voltage signals into the motor, followed by the decomposition of the high-frequency response current using the recursive least squares method. This results in the identification of the motor inductance parameters and rotor initial position, based on the outcomes of the motor rotor polarity identification. Compared with traditional methods, this approach has the advantages of eliminating the delay effect of digital system sampling and control, and of not requiring filters to demodulate the high-frequency response current. Furthermore, the identification results are less affected by the nonlinearity of the inverter. Both simulation and experimental validation support the validity of the method. The experimental results demonstrate that the errors between the identified values of the inductance of the cross and straight axes and the design value are 0.15% and 0.97%, respectively. Additionally, the deviation between the identified results and the actual value of the initial position of the rotor is 1.76°, indicating a high level of identification accuracy.