Study Of The Speed Sensorless Vector Control System By EKF

The advantage of AC motor is itself, with strong structure, no brush, easy maintenance, low price, light weight etc. However,for AC motor speed control, the classic AC induction motor speed is only limited to the changes in level, transformer, circuit series resistance of the rotor speed regulation mode. Compared with DC motor's good speed performance, it initially makes the application of AC motor far behind with DC motor's. After vector control theory proposed, the problem of AC motor speed control is sloved with the laws of DC motor control. Vector control technology with no speed sensor not only reduces the cost but also raises the reliability of the motor's run.It just estimated the motor speed by three-phase current. With the development of power electronics technology,it has become one of the most effective methods to estimate the motor speed by EKF.First, this paper introduces the introduction of speed sensorless vector control system proposed and the research status. The second chapter introduces the basic mathematical model of motor vector control system and the basic theories. In the basis of the speed sensorless vector control system,the third chapter introduces that the rotor speed estimation is identificated by EKF. With the high operation speed, high precision development of power electronic devices,it has made EKF algorithm become the best motor speed estimation algorithm.Under the speed sensorless vector control basic theory and EKF algorithm, the fourth chapter correspondes simulation model by Matlab/Simulnik. Finally, this paper dedicated motor control DSP chip in order to test the speed estimation model performance by EKF. The results again show that the velocity estimation model estimation accuracy is high and the model has strong fault tolerance and approximation ability of nonlinear systems.