Parameter Identification Of Induction Motor DTC System

With the rapid development of the power and electric system and computer technology, AC drivers are replacing the convention DC drivers gradually. The control method of induction Motor is very excessive. Comparatively, DTC is much more advanced. In DTC, the mathematic model of induction motor is analyzed in the stator coordinate and the flux and torque are controlled directly. Therefore, coordinate rotate transformation and complicated computation are saved and the control method is novel, simple and direct.According to the existing problems of DTC, a fuzzy observer of the stator resistance is proposed to measure the changement of the stator resistance online, and it is expected seriously that the value of stator resistance could be measured accurately. Then, based on the U-I model of induction motor, the value of stator flux can be computed. It can lessen the stator flux estimated error caused by the changement of stator resistance. Firstly, the principle of tranditional DTC and stator resistance fuzzy observation is introduced in this thesis. The DTC system with the fuzzy observer of stator resistance on the platform MATLAB/SIMULINK is simulated and the simulation results are also analysed. Secondly, the hardware platform of digital AC driver control system based on high performance digital signal processor dsPIC30F6010 and intelligent power module PM30CSJ6010 has been introduced, and realization of the control function and circuits is analyzed specifically, as well as the algorithm realization of the software design process and the main function parts of control systems. Finally, the experiment data are acquired by PC through serial communications interface and the experiment results are analyzed. And then, the problems eager for being resolved in the future has been prospected.