PLL type estimator applied in PMSM sensorless control for speed and position

This paper presents a novel estimation algorithm for speed and position of Permanent Magnet Synchronous Machine (PMSM) based on Phase Locked Loop (PLL) technique. The invention in this sensorless control scheme combines the PLL methodology with a modified PMSM mathematical model expressed in the arbitrary rotating frame. Only stator voltages and currents are required in the algorithm estimating modified stator and rotor magnetic flux. The control strategy principle is based on the advantage of PLL-type structure to successfully track rotor flux with the required stability and accuracy. Simulation results demonstrate the effectiveness and performance analysis of the proposed position and speed estimation method.