三相电压型PWM整流器的自抗扰控制研究

Research on active disturbance Rejection control of three-phase voltage Type PWM rectifier

摘要:

三相电压型PWM整流器是一个多输入多输出的强非线性结构，并对三相电压型PWM整流器的数学模型和自抗扰控制器进行了原理分析。为了提高整流系统中非线性、抗扰性及参数摄动控制问题，采用一种改进型的非线性自抗扰控制方案且给出其离散形式。然后，重新构造了常规自抗扰控制器中非线性状态误差反馈控制率（NLSEF）和扩张状态观测器（ESO）的非线性函数，以此来克服非线性函数的不平滑性能，从而减小整流系统输出的高频颤振现象。通过MATLAB/Simulink仿真分析和搭建实验样机验证，改进型自抗扰控制与常规自抗扰控制进行对比，结果表明了新构造的自抗扰控制策略具有更好的动、静态特性，改善了常规自抗扰控制时系统对交流侧电压和负载突变敏感的缺点，并降低了交流侧电流总谐波含量(THD，Total harmonic distortion)且直流侧电压具有更好的鲁棒性。

Abstract:

The three-phase voltage-type PWM rectifier is a strong nonlinear structure with multi-input and multi-output. The mathematical model and active disturbance rejection controller of the three-phase voltage-type PWM rectifier are analyzed.In order to improve the nonlinear, disturbance rejection and parameter perturbation control problems in the rectifier system, an improved nonlinear active disturbance rejection control scheme is adopted and its discrete form is given. Then, the nonlinear functions of NLSEF and ESO in conventional active disturbance rejection controllers are reconstructed to overcome the non-smooth performance of the nonlinear functions and reduce the high frequency chatter phenomenon of the rectifier output. Through MATLAB/Simulink simulation analysis and experimental prototype verification, the improved ADRC is compared with conventional ADRC. The results show that the new ADRC has better dynamic and static characteristics, and improves the disadvantages of conventional ADRC system sensitivity to AC side voltage and load mutation. In addition, the Total harmonic distortion (THD) is decreased and the DC voltage is more robust.