Application of Reduced-Order Extended Kalman Filter in Permanent Magnet Synchronous Motor Sensorless Regulating System

Aim at the existing problems of the Extended Kalman Filter (EKF) in speed sensorless control system of permanent magnet synchronous motor (PMSM), such as too much computation, complex structure and high cost. A kind of Reduced-order Extended Kalman Filter (Reduced-order EKF) in speed sensorless control system of PMSM is proposed in this paper. By estimating the counter electromotive force according to the stator current observed as state variables, the reduced-order and the decoupling of the system equation is realized. On this condition, the motor speed is estimated by using the Reduced-order EKF. Compared with the traditional method of EKF, the system order is reduced, the process of iteration of speed estimation is greatly simplified and it is easy to realization of the digitalization system by using this method. The simulation results have shown that this system has fast reacting speed, good dynamic performance, adjust parameters easily, and beneficial to realize digital system.