High performance IPMSM drives without rotational position sensors using reduced-order EKF

An extended Kalman filter (EKF) based approach for position sensor elimination in interior permanent magnet synchronous motor (IPMSM) drives is presented in this paper. The EKF is capable of estimating system parameters and state variables for the IPMSM by eliminating virtually all influences of structural noises in the vector control scheme. This paper presents a design method of a reduced-order EKF. Position and angular speed of the rotor are obtained through the reduced-order EKF only by measuring stator currents. Also, due to an angle modification scheme with error tracking, the sensorless drive system is robust to parameter variations. Simulation and experimental results are provided to verify the proposed approach based on the reduced-order EKF.