Research On Parameter Indentification Of Vector Controlled Asynchronous Motor

The vector control technology base on field orient of AC asynchronous machine is a important subject in AC driving system,its principle is through coordiate conversion,divide the stator current into torque component and excitating component,control individually,to achieve the decouple and control of the torque and magnetic flux of asynchronous motor handily.In field orient control,the detect accuracy of rotor magnetic flux is nearly related to the motor parameters,the accuracy of motor parameter not only affect magnetic flux,but also affect the accuracy of field orient.Therefore,the control quality of the system is greatly depends on the accuracy of motor parameters.To realize vector control of a asynchronous motor,the first thing to do is identify its parameters.The text contain a research of the parameter identification of the asynchronous motor T form equivalent circuit.Implement a method of parameter off line self detect,simulation and experiment studies proved this method is correct.Most of the vector control systems are designed based on the principle of rotor flux feedback. Among those systems, the rotor time constant exerts a dominant role in the loss of dynamic performance because it is sensitive to the temperature variation and magnetic saturation. the typical methods to indentify rotor time constant are: method of Kalman extended filtering,the model reference self adaptive method,etc.These methods all need large quantity real-time computation,they all have one drawback:depend on stator resistance.this make them don't have a good performance in high performance drive control system. This paper presents a new scheme for online estimation of rotor time constant using dq representation of the model in the rotor reference frame and measurements of accessible motor variables only. The estimator is tested by simulation in the MATLAB/SIMULINK environment.