Sensorless vector control for high-speed permanent magnet disk synchronous motors

A sensorless vector control method for high-speed permanent magnet disk synchronous motors (PMDSM) is presented based on the improved sliding mode observer (SMO). A sigmoid function is introduced into the observer and an algorithm of the improved SMO for estimating the position and speed of the high-speed PMDSM. Simulation of the sensorless vector control for the PMDSM is performed on MATLAB/Simulink. The estimation error of position and speed, and estimated back-EMF of the PMDSM are studied based on the simulation. The results demonstrate that the proposed control method can quickly and accurately trace the given speed and achieve a good control performance.