Nonlinear sensorless speed tracking control for PMSM with unmodeled electromotive forces

Abstract In this paper, a sensorless speed tracking control scheme is proposed for Permanent Magnet Synchronous Motor (PMSM) with unmodeled electromotive forces. Specifically, one observer is developed to estimate the angular velocity of PMSM and the estimated value is injected into a novel nonlinear feedback controller. The unmodeled electromotive forces are not estimated. The influences of the unmodeled electromotive forces on the speed tracking performance are overcome by constructing corresponding nonlinear damping terms in the controller. Under certain assumptions, the rigorous proof of the stability of the closed‐loop system is completed with Lyapunov theory. All the dynamic signals are bounded. Furthermore, the estimation error and the tracking error can converge to an arbitrarily small value by choosing the control parameters appropriately large. Finally, the simulation results of constant and time‐vary speed tracking illustrated the effectiveness of the proposed controller.