Research Technology Of IM Parameter Identification Based On Mras

Because of simple structure, convenient, cheap, easy to run, Induction motor in theindustrial sector has played a pivotal position. Especially high-power motor, theadvantage is more obvious. The vector control in induction motor control method has avery obvious advantage, but the vector control of induction motor needs accurate motorparameters, and inaccurate parameters lead the failure of field orientation, and theexcitation current and torque current couple, and it results in motor speed and torqueshock. There are two main reasons to lead motor parameters inaccurate, the first is themotor parameters of the controller set the inaccurate initial values, and the second isbecause of temperature and current mutations, the changing parameters causes theactual values and the set values are inconsistent when the motor running. This paper ismainly against the issues above, the research of offline parameter parameteridentification and online parameter identification is done.Firstly, this paper analyzes the mathematical model of the induction motor and thestructure of vector control system, and builds vector control system based on rotor fluxobserver. In order to improve the identification accuracy of the motor parameters, thispaper analyzes the offline parameter identification theory of induction motor, andidentifies stator resistance, rotor resistance, stator and rotor leakage inductance andmutual inductance, and gains the accurate value of the motor parameter identification byexperiment.Secondly, to solve the problem of parameters as temperature and current mutationschanging when running the motor, by analyzing the affect of motor parameters on motorperformance, two on-line identification methods based on rotor flux model and based onreactive power model are proposed to identify motor’s time constant on the base ofMRAS theory. By using the Matlab/Simulink and comparative analyzing of these twomethods, this paper gains that based on reactive power model is more accurateidentification method to identify the parameters.Thirdly, this paper builds a hardware platform in the core of Infineon32-bitmicrocontroller XMC4500, and designs drive control circuit. Based on closed-loopvector control, this paper implements the online parameter identification algorithmbased on reactive power model reference adaptive method. Through experoments ofstep reponse and tracking performance, this paper gains that the online parameteridentification algorithm based on reactive power model reference adaptive method canbe good at identifying the parameters.