Research On Full-Order Flux Observer For Induction Motor Based On ADI Loop Simulation System

Speed estimation is the key to the speed-sensorless vector control system, so the accurate estimation of speed is particularly important. There are many speed estimation schemes existed, but the adaptive full-order flux observer has a better performance on speed estimation. So we use the adaptive full-order flux observer for the speed estimation of induction motor in this thesis and the main research contents are as follows:First, several common speed estimation methods and their advantages and disadvantages are introduced. besides, the corresponding dynamic mathematical equivalent model of induction motor in different coordinate systems are derived. We have briefly describes the basic idea of vector control model magnetic field-oriented control, and the principle of SVPWM.Then, The motor state estimation equations are derived. We have analyzed the pole distribution and the relationship between the pole locus of the motor and the rotor speed is compared. The method of model reference adaptive system is studied, and its disadvantages are analyzed. On this basis, the adaptive full-order flux observer is designed and the corresponding simulation model is built. In this paper, we have use the robust control theory, the linear matrix inequality (LMI) to select the observer’s gain, and the adaptive laws that meet the requirements of stability and convergence are derived. The simulation result shows that the adaptive full-order flux observer can well follow a given value, and has good ability to resist disturbance, which can guarantee the stability of the system in full speed range.Finally, The hardware implementation platform based on the ADI loop simulation system was designed, and the prototype test was carried out. The simulation and experimental results show that the control system has good performance, speed estimation is fast and accurate to track the real speed. The built model is reasonable and effective, which has perfect steady and dynamic performance, and the method of adaptive full-order flux observer have good robustness in full speed range.