Speed estimators based control of permanent magnet syncronous motor

This paper deals several widely used, closed-loop discrete-time, speed estimators, used for the digital control of permanent magnet synchronous motors (PMSM). Aim of the paper was to develop a rotor position/speed sensorless control system with performance comparable to the sensor-based control systems for PMSMs over their entire operating range, including low-speed operation. Simulation analyses are performed and estimation errors are presented and compared for the proposed methods. After centralization of the obtained results, the authors indicate which method of speed estimation is better to be used at high or low speeds.