Parameter Identification Of Induction Motor Vector Control System

This paper focuses on the parameters estimation of vector control system of asynchronous motor. At present, the vector control strategy works well in the field of alternating current speed regulation, which bases on rotor flux orientation and solves the decoupling problem of stator current through rotating coordinate system transform. Because the vector control based on the accurate observe of rotor flux, its performance is greatly affected by the change of motor parameters. However, asynchronous motor is influenced by working condition and its parameters change. Especially the resistance and inductance of rotor change as the temperature, resulting in the incensement of observing error of rotor flux and incomplete decoupling of stator current so as to reduce the performance of the vector control system.The components and working principle of vector control system of asynchronous motor is presented briefly to prove that it is necessary to identify motor parameters. And then the influence of parameters changing on observation accuracy of rotor flux is quantitatively analyzed by Matlab/Simulink and the influence on the dynamic and static performance of vector control system is also analyzed, so it is important to identify motor parameters.In order to restrain the blight of parameters changing on vector control system, model reference adaptive is used for rotor time constant of induction motor on-line estimation. The method of identifying rotor time constant based on rotor flux model is deduced but the change of stator resistance affects heavily on the identification accuracy. Therefore, the method of identifying rotor time constant based on reactive power model is used to reduce the influence of the change of stator resistance, and fuzzy control technology is used to improve adaptive law to increase convergence rate, and then the method of identifying rotor time constant based on model reference fuzzy adaptive is proposed. The method is applied in vector control system, and the simulation result in simulation experiment by Matlab/Simulink shows that the method of identifying rotor time constant has high accuracy and convergence rate, and it improves the performance of vector control system effectively.