Research On Induction Motor Vector Control Based On Adrc

Induction motor is widely used in modern industry, so high performance control of induction motor drives is urgently required. However in real-time implementation, precise decoupling which requires accurate motor parameters can't be fully realized due to significant plant uncertainties such as external disturbances, parameter variations and plant nonlinear dynamics. This may deteriorate the dynamic performances of flux and torque significantly. To achieve high dynamic performance of drive system, a nonlinear auto-disturbance rejection controller is presented in this paper.Active Disturbance Rejection Controller (ADRC) is a new type of controller, which is propounded by Hanjingqing in the 90s, 20th century. The controller can overcome the disadvantage of the classic PID controller and make the system achieve high dynamic performance. One of the most important things for the control system is to observe accurately the value of rotor flux in a field-oriented induction motor drive system, the other is to regulate the control system rapidly and precisely.The thesis not only studies deeply and systemically the theory of ADRC, but also analyzes the structure and function of each part. The auto-disturbance rejection controller is composed of three parts: tracking-differentiator, extended state observer and nonlinear state error feedback control law .By using the extended state observer the proposed controller can estimate the derivative signals accurately and precise decoupling of induction motor is achieved. In addition, the proposed strategy realizes the disturbance compensation without accurate knowledge of induction motor parameters, so that the accurate model of induction model is not required. That means the design of auto-disturbance rejection controller is independent of the controlled system model. Based on predecessors' research, it designs the ADRC, which is applied for a rotor field-oriented induction motor drive system, sets up the simulation and bets the result. The simulation and experiment results show that the controller ensures very good robustness and adaptability under modeling uncertainty and external disturbance, and it is concluded that the proposed controller produces better dynamic performance such as small overshoot and fast transient time than conventional PID controller in the overall operating conditions.