Reduced-order resonant regulator-based position harmonic error suppression for sensorless permanent magnet synchronous motor drives

In this article, to improve the accuracy of rotor position estimation in sensorless permanent magnet synchronous motor drives, a reduced-order resonant regulator for the rotor position sliding mode observer is proposed. Since fundamental back electromotive force can be utilized to calculate the rotor position, a mathematical model for the observer is first established based on the analysis of estimation fluctuation error, where a reduced-order resonant regulator is applied to extract the fundamental back electromotive force. Then, the phase-locked loop with back electromotive force normalization is used to compute the rotor position and speed. Finally, the experimental bench of permanent magnet synchronous motor driving system is built. The experimental results verify that the proposed strategy can effectively reduce the estimation error and meanwhile improve estimation accuracy.