The Robust Observer for Sensorless Control of Permanent Magnet Synchronous Motor

A robust observer based sensorless control method for the permanent magnet synchronous motor (PMSM) is proposed in this paper. First, the robust observer is proposed to estimate the back electromotive force (EMF) of the PMSM regardless of the uncertainty. Second, the stability of the proposed robust observer is analyzed by using the Lyaunov theory. Third, by the estimated back EMF, the phase locked loop (PLL) based approach is proposed to calculate the rotor position and speed of the PMSM. Finally, the simulation is conducted to verify the effectiveness of the proposed method. Compared with the traditional sliding mode observer (SMO), the proposed robust observer approach has the better system performance for the estimation of rotor position and speed, while it can effectively eliminate the chattering of the observer.