采用自抗扰控制器的高性能异步电机调速系统

矢量控制技术已被广泛地应用于高性能异步电机调速系统中，然而，由于在实时控制中存在严重的外部干扰，参数变化和非线性不确定因素，基于精确电机参数的准确解耦很难实现，并且磁通和转矩的动态性能也受到严重的影响，为了提高调速系统的动态性能，该文提出了一种可以取代经典PID控制器用于异步电机调速的非线性自抗扰控制器。自抗绕控制器由三部分组成；跟踪微分器，扩张状态观测器和非线性状态误差反馈控制律，利用扩张状态观测器，自抗绕控制器可以估计出系统状态变量及其广义导数，从而实现异步电机的精确解耦，此外，上述控制录需要精确电机参数就可以实现干扰补偿，这使得自抗绕控制器的设计能够独立于异步电机的精确数字模型。仿真和实验结果表明，相对于经典PID控制器，自抗绕控制器在较宽的调速范围内具有更好的动态性能以及对负载扰动，电机参数变化都具有更好的鲁棒性。

HIGH PERFORMANCE CONTROL OF INDUCTION MOTOR BASED ONAUTO-DISTURBANCE REJECTION CONTROLLER

The field oriented control technique is widely used in high performance motion control of induction motors. 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 which substitutes the classic PID controller to the control of induction motor is presented in this paper. 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, and this controller can achieve good adaptability and robustness as well. 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.