Closed-loop Parameter Identification of Permanent Magnet Synchronous Motor Considering Nonlinear Influence Factors

This paper proposes a closed-loop identification method based on an AC servo control system for permanent magnet synchronous motor (PMSM) parameters. The parameters include the inductance of the quadrature-direct axis, resistance of the stator, and magnetic flux linkage of the rotor. First, the nonlinear factors influencing the parameter identification accuracy—the motor model error caused by non-sinusoidal flux, switch dead zone of the inverter, and rotor position feedback delay of the encoder—were analyzed to develop corresponding compensation methods. Second, an experimental system was developed, and the proposed method was implemented and evaluated. The analytical and experimental results showed that the identified inductance-current curve was consistent with the results of finite element analysis after compensation, while the estimated resistance and flux were closed to the measured values. These results confirm the validity of the proposed method.