Position sensorless control of PMSM based on Extended State Observer

This paper proposes an Extended State Observer (ESO) to achieve the sensorless position control of permanent-magnet synchronous motor (PMSM). An Extended State Observer (ESO) is built according to the back electromotive force (EMF) model. It uses a nonsmooth2 structure to observe all states of the controlled object and the inside and outside disturbance of the system. Original system can be converted into linear certain system by this. Furthermore, stability and convergence analysis of the closed-loop control are given based on the Lyapunov stability theory. Simulation results verify the asymptotic convergence of ESO.