The Speed Sensor-less Vector Control System Of The Asynchronous Motor Based On Kalman Filter

With the dramatic development of electronic technology and computer science, the speed regulation technology of alternating current machine based on them has made considerable progress. The speed-sensorless vector control of induction motor has become a focus gradually as an important approach direction in modern alternating current machine control.Firstly, research for control strategies of alternating current induction motor in recent years was introduced, and the advantages and disadvantages of different strategies were compared. Based on the theory of electromagnetism field, the mathematical model building of alternating current induction motor is educed in different coordinates, including the model in 3-phase coordinate, the model in 2-phase coordinates. And the principle of vector control and coordinate conversion is also presented; it offers the further theoretical foundation of the research of the speed-sensorless vector control system of induction motor.The principle of extended Kalman filter and its application in the vector control system are the emphasis of this thesis, and a model of the speed-sensorless vector control system based on extended Kalman filter is built under the environment of Matlab/Simulink, and the speed-sensorless regulation control of induction motor is realized. The results of the simulation prove that the speed-sensorless vector control system of induction motor based on extended Kalman filter is valid and rational. However, extended Kalman filter has some defects, so this paper introduced the principle of unscented Kalman filter and its application. The model of the control system is built, and the results of the simulation are satisfactory.Experiment is done based on the DSP design system for digital motor control. The extended Kalman filter algorithm is carried out to estimate the rotor speed and fluxes, and space vector pulse width modulation algorithm. The experiment results prove that the method that extended Kalman filter applied to the speed and flux's estimation of the asynchronous motor is feasible.