Grid‐connected voltage source inverters with LCL filters have been widely used for distributed generation systems in renewable energy systems. The presence of LCL resonance influences the overall performance and complicates the system control design, especially when the uncertainties caused by the component parameter variations and disturbances are considered. In order to improve the system performance under uncertain conditions, this paper presented a model‐based discrete sliding mode control (SMC) with disturbance observer (DOB) for three‐phase LCL‐filtered grid‐connected inverters. In this work, the inverter model is modified by using a virtual damping resistor to eliminate the resonance of the LCL filter and improve the stability, even consider the variations of the grid impedance. To save the sensors and predict the forward step of the state variables, a discrete state observer is adopted in the control. To enhance the robustness of the system, a DOB is designed in the SMC controller to estimate the disturbances so that the system uncertainties can be effectively compensated. Finally, comparative simulations and experiments are constructed to demonstrate the effectiveness of the proposed method. © 2020 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.

中文翻译：

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具有干扰观测器的基于模型的离散滑模控制，适用于三相LCL滤波并网逆变器

具有LCL滤波器的并网电压源逆变器已广泛用于可再生能源系统中的分布式发电系统。LCL谐振的存在会影响整体性能并使系统控制设计复杂化，尤其是在考虑到由组件参数变化和干扰引起的不确定性时。为了提高不确定条件下的系统性能，本文针对三相LCL滤波并网逆变器，提出了一种基于模型的离散滑模控制（SMC），带有扰动观测器（DOB）。在这项工作中，通过使用虚拟阻尼电阻来修改逆变器模型以消除LCL的谐振甚至可以考虑电网阻抗的变化来过滤并提高稳定性。为了节省传感器并预测状态变量的前进步，在控制中采用了离散状态观察器。为了增强系统的鲁棒性，在SMC控制器中设计了DOB来估计干扰，从而可以有效地补偿系统的不确定性。最后，通过比较仿真和实验来证明所提方法的有效性。©2020日本电气工程师学会。由Wiley Periodicals LLC发布。