The Application Of Active Disturbance Rejection Controller In The Research Of High Performance Motor Control

The field oriented control technique is widely used in high performance motioncontrol of induction motors. However, in real-time implementation, precisedecoupling which requires accurate motor parameter can't be fully realized due tosignificant plant uncertainties such as external disturbances, parameter variations andplant nonlinear dynamics. This may deteriorate the dynamic performances of flux andtorque significantly. To achieve high dynamic performance of drive system, anonlinear active disturbance rejection controller which substitutes the classic PIDcontroller to the control of induction motor is introduced in this paper. The structure and characteristics of ADRC are studied in this dissertation.Simulation and experiments present the relationship between the performance ofADRC and its parameters presented in this paper. This paper also gives themodulation method of ADRC. The design of ADRC in control system of inductionmotor is discussed in this paper. Its feasibility is testified by mathematical illation.The active disturbance rejection controller is composed of three parts:tracking-differentiator, extended state observer and nonlinear state error feedbackcontrol law. By using the derivative signals accurately and precise decoupling ofinduction motor is achieved. In addition, the proposed strategy realizes thedisturbance compensation without accurate knowledge of induction motor parameters,so that the accurate model of induction model is not required. That means the designof active disturbance rejection controller is independent of the controlled systemmodel, and this controller can achieve good adaptability and robustness as well. Thesimulation and experiment results show that the controller ensures very goodrobustness and adaptabitity under modeling uncertainty and external disturbance, andit is concluded that the proposed controller produces better dynamic performancesuch as small overshoot and fast transient time than conventional PID controller inthe overall operating conditions.