Improved Grid-Side Current Control of LCL-Filtered Grid-Tied Inverters Under Weak Grid Conditions
Improved Grid-Side Current Control of LCL-Filtered Grid-Tied Inverters Under Weak Grid Conditions
复制标题
弱电网条件下 LCL 滤波并网逆变器改进的网侧电流控制
DOI：
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发表时间：
2019
期刊：
影响因子：
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通讯作者：
Dianguo Xu
中科院分区：
文献类型：
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作者：
A. Benrabah;F. Khoucha;K. Marouani;Abdelaziz Kheloui;A. Raza;Dianguo Xu
三相电压型逆变器是可再生能源并网的关键部件。为了在并网逆变器中实现可接受的电流谐波抑制并满足并网建议，通常使用电感-电容-电感(LCL)型滤波器作为逆变器与电网之间的接口。然而，该滤波器表现出一个谐振峰值，应该适当地抑制该峰值以确保系统稳定。此外，电网阻抗的变化，主要是在弱电网条件下，可能会移动谐振频率，从而影响控制器的设计。本文提出了一种基于陷波控制的有源抑制LCL滤波器谐振的系统方法。为了改善电网阻抗变化时的控制性能，还考虑了一种自适应方法。计算机仿真结果表明了该控制方法的有效性和鲁棒性。
Three-phase voltage source inverters are key parts to integrate renewable energy resources into the electrical grid. In order to achieve an acceptable attenuation of current harmonics in grid tied inverters and meet grid interconnection recommendations, an inductor-capacitor-inductor (LCL) type filter is commonly used as an interface between the inverter and the grid. However, this filter exhibits a resonant peak that should be properly damped to ensure system stability. Moreover, grid impedance variations, mainly under weak grid conditions, may shift the resonance frequency which compromises the controller design. This paper proposes a systematic approach to actively damp the LCL filter resonance using the notch filter-based control. An adaptive approach is also considered to improve the control performance under grid impedance variations. Computer simulations results are presented to demonstrate the effectiveness and robustness of the proposed control method.