Sensorless control of a permanent magnet synchronous motor-application to a hoist drive

This paper compares methods for estimating the rotor angle and angular speed of a slowly rotating permanent magnet synchronous motor. The estimation methods studied are the model reference adaptive system and nonlinear full-order observer based on the exact linearization technique. The applicability of the estimators for closed-loop, estimator-based, feedback control was studied using simulations and measurements with a real PMSM drive.