Parameter Identification For Vector Controlled Induction Motor

Induction motor is the most widely used power equipment at present. Compared with other kinds of motors, it has the advantage of simple structure, steady operation, low cost and lasting long. With the development of Vector Control and Direct Torque Control strategy, induction motor speed regulation technology has seen comprehensive applications on areas such as inverter, servo system, elevator and so on. For both control methods listed above, precise motor parameters are needed which can not read on nameplate. Moreover, the needed parameters of one motor changes with time. Therefore, parameter identification of motors, especially in-time identification, has great significance for induction speed regulation system.This paper elaborates on paramter identification for vector control system used in induction motor. Based on induction motor model and vector control strategy, the author describes off-line parameter identification in two methods firstly. Secondly analyses are given on influenc on magnetic flux, electromagnetic torque and speed responce brought by detuned motor parameters. In the last, theoratic analyses and simulation validations are achieved with EKF( Extended Kalman Filter) method for the purpose of in-line parameter identification. Several circumstances such as variable load, inprecise system model, measure noise are also considered. In the view of control system, this paper discusses the robustness of EKF algorithm. Based on theoratical analyses and simulations in Simulink, conclusion is made that EKF algorithm can be used for in-line parameter identification for induction motor.