A Three‐Stage Integrated Sliding Mode Observer‐Based Position Estimation Scheme for PMSM

ABSTRACT To further improve the position estimation performance of permanent magnet synchronous motor (PMSM) and reduce the high‐frequency chattering of the sliding mode observer (SMO)‐based position estimation strategy, this paper proposes a three‐stage integrated SMO‐based sensorless position estimation algorithm that integrates an adaptive filter and an orthogonal phase‐locked loop. By selecting the hyperbolic tangent function with optimal parameters as the switching function of the sliding mode observer, the harmonic contents in the observed back electromotive force (Bemf) can be reduced and the use of a low‐pass filter can be avoided. To filter out the high‐frequency interference in the Bemf, the synchronous adaptive filter is also adopted. Finally, an improved orthogonal PLL with forward and reverse functions is adopted to estimate the rotor position, further improving the accuracy of position estimation. To verify the effectiveness of the proposed method, detailed experiments are implemented in a rated 60 W PMSM motor drive system. Trial Registration: No clinical trial.