A robust optimized active disturbance rejection control (ADRC) based grid voltage sensorless current controller is developed for an LCL -filtered grid-connected inverter (GCI) via a predictive control approach under various sources of disturbance, including the model uncertainties, the LCL inherent resonance phenomenon, and nonideal grid environment. Aiming to improve the sinusoidal reference tracking performance as well as to reject lumped sinusoidal disturbances in the control practice, a resonant extended state observer is integrated into the ADRC structure, which guarantees a rigorous stable operation of inverter for bounded filter parameter uncertainties and adverse grid voltage conditions. The grid frequency adaptability is thoroughly considered in the controller design process and synchronization technique, offering an extra capability for GCI to operate under different grid voltage frequency levels or even the frequency deviation caused by grid fault events. Robustness against parameter uncertainty and system stability is analyzed through the discrete-time frequency analysis and pole-zero map approaches. The simulation and hardware experiments are conducted for GCI with LCL filter parameters designed for two typical regions (i.e., the resonance frequency is less and greater than one-sixth of switching frequency) to validate the theoretical analysis and the effectiveness of the proposed control method.

中文翻译：

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具有谐振扩展状态观测器的电网电压无传感器 LCL 滤波逆变器的优化有源抗扰控制

基于电网电压无传感器电流控制器的鲁棒优化自抗扰控制 (ADRC) 被开发用于 LCL 滤波并网逆变器 (GCI) 在各种干扰源下通过预测控制方法，包括模型不确定性、拼箱固有的共振现象，以及非理想的电网环境。为了在控制实践中提高正弦参考跟踪性能并抑制集中的正弦扰动，在 ADRC 结构中集成了谐振扩展状态观测器，保证了逆变器在有限滤波器参数不确定性和不利的电网电压下的严格稳定运行状况。在控制器设计过程和同步技术中充分考虑了电网频率适应性，为GCI提供了在不同电网电压频率水平甚至电网故障事件引起的频率偏差下运行的额外能力。通过离散时间频率分析和零极点映射方法来分析对参数不确定性和系统稳定性的鲁棒性。为两个典型区域（即谐振频率小于和大于开关频率的六分之一）设计的 LCL 滤波器参数验证了所提出的控制方法的理论分析和有效性。