An improved rotor position and velocity estimation technique for PMSM based on modified machine model

This paper presents an improved method for the estimation of rotor speed and position of PMSM. Since the information of rotor speed and position obtained from Sliding Mode Observer in estimated rotor frame usually carries noise because of the switching input and the noise increase when the speed is higher, an Extended Kalman Filter is designed to eliminate the noise and get the accuracy information, meanwhile the outstanding robustness properties against system parameter uncertainties and external disturbance remains. The results of the simulation demonstrate the effectiveness of the proposed method using Matlab/Simulink facility.