The Study Of The Induction Motor Passivity Control System Based On The Adaptive Observer

Induction motor is simple, inexpensive, and reliable operation, which make it a large number of applications in the industrial, transportation, et al. But Induction motor has typical nonlinear characteristics of strong coupling. How the making use of the advanced control techniques to improve the performance of the induction motors is still a challenging research topic. Passivity-based control of nonlinear induction motors, which can achieve global asymptotic stability and the robustness to external disturbances, has been proven an effective method to tackle the problem. Noting that the rotor flux and other physical quantities are difficult to be measured directly and the stator resistance parameters will change during the operating of the system and result in the increasing of the speed error, and even lead to instability, it is important to utilize the Lyapunov stability theory and adaptive observer to investigate the torque tracking control problem based on passive theory. The works in the thesis can be summarized as follows:First, a dynamic model of the induction motor was proposed and the strictly passive property of the system was proven. A torque tracking controller with damping injection is proposed, which can take advantages of the passivity property of the induction motors and fasten the convergence rate.Secord, through regarding the stator current, rotor flux as the state variables, an adaptive flux observer was put forward, which can greatly simplify the structure of the observer and reduce the estimation speed and accuracy. Based on the Lyapunov stability theory, we design a speed and stator resistance adaptive control law to improve the robustness of the system change motor parameters.Third, the chosen of observer gain is discussed. Simulation results show that the proposed adaptive-observer-based passivity control strategy can effectively improve the static and dynamic performance of the induction motor.