提出了一种基于改进线性扩张状态观测器（linear extended state observer, LESO）的电力电子负载自抗扰控制策略，解决了传统控制方法动态性能较差、对系统参数依赖等问题。建立LCL(line current loop)变换器在α-β坐标系下的数学模型，分析线性自抗扰控制（linear active disturbance rejection control, LADRC）中LESO的误差，对观测器控制输出部分的结构进行改进，以减小观测值中来自控制输出信号的误差。通过LESO求取指令电流微分，引入线性误差反馈控制率中，减小传统LADRC的固有误差。分析系统的频域特性，研究参数和控制策略对系统的影响。通过仿真和半实物仿真，验证了改进策略能明显改善传统LADRC跟踪动态信号时的波形畸变、相位滞后等问题，使变换器实现对各类负载的精确模拟。
英文摘要:
A power electronic load active disturbance rejection control strategy based on improved linear extended state observer (LESO) is proposed, which solves the problems of poor dynamic performance and dependence on system parameters of traditional control methods. The mathematical model of line current loop (LCL) converter in α-β coordinate system is established, the error of LESO in linear active disturbance rejection control (LADRC) is analyzed, and the structure of the control output part of the observer is improved to reduce the error from the control output signal in the observation value. The instruction current differential is calculated by LESO, and the linear error feedback control rate is introduced to reduce the inherent error of traditional LADRC. The frequency domain characteristics of the system are analyzed, and the effects of parameters and control strategies on the system are studied. Finally, simulation and hardware-in-the-loop simulation show that the improved strategy can significantly improve the waveform distortion, phase lag and other problems of traditional LADRC when tracking dynamic signals, so that the converter can achieve accurate simulation of various loads.