Based On Extended Kalman Filter Position Sensorless Control For Permanent Magnet Synchronous Motor

The permanent magnet synchronous motor (PMSM) has broadly applied thanks to its superiority-performance. The traditional analysis on theory and designing technique has developed maturely. Now the wider applications of PMSM depends on the further research upon its control methods. In practice, VVVF strategy is used in operating the PMSM popularly. However, if the VVVF control the PMSM whose rotor without damping windings, it will induce the whole system instability sometimes when the motor runs beyong certain frequency. In this paper, the study focuses on sensorless control of a PMSM.This paper advance a sensorless control method based on Extended Kalman Filter (EKF). It expatiates the mathematic model of PMSM and the basis theory of Kalman Filter. In dq rotary reference frame, EKF arithmetic is employed to estimate rotor position and speed on-linely. The filter arithmetic measures motor current and inverter direct current bus voltage only. The method needn't to rebuild the motor. It is reliable and durable. The system achieves current and speed close loop vector control using estimated position and speed. The estimate way of initial rotor poison based on magnetic saturation is also advanced. The paper adopts spacial vector pulse width modulation (SVPWM) realized vector control. SVPWM can output the voltage vector at any position. Without increasing the switch frequency of power element and the complexity of system, it can improve the system's stability and control performace.The simulation result in Matlab 6.5 shows that the proposed strategy has stronger robustness and satisfactory performance.