In this article, an optimal design procedure of shunt RC damped LCL filter is discussed. The proposed design procedure finds the minimum damping resistance to guarantee the stability of the grid-current controller without affecting the effectiveness of the filter. This minimum value is derived using the factorized filter input admittance and filter forward transadmittance. The proposed factorization procedure allows us to have an analytical expression of system poles and zeros. Moreover, the minimum damping resistor is determined upon the desired crossover frequency and the desired phase margin of the grid-current controller. After that, an objective function is assumed, and an optimization problem is formulated to minimize the physical size of the filter by minimizing the total capacitance and inductance and by minimizing the filter ripple content as well. Accordingly, the proposed objective function minimizes the filter physical size and filter power losses and, hence, enhances filter's efficiency. A prototype demonstrates and validates the proposed filter design and analysis experimentally.

中文翻译：

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并网电压源逆变器并联 RC 阻尼 LCL 滤波器稳定性分析和优化的解析分解模型

在本文中，讨论了并联 RC 阻尼 LCL 滤波器的优化设计程序。所提出的设计程序找到了最小阻尼电阻，以保证电网电流控制器的稳定性而不影响滤波器的有效性。该最小值是使用分解的滤波器输入导纳和滤波器前导导纳得出的。建议的分解程序允许我们对系统极点和零点进行解析表达式。此外，最小阻尼电阻器取决于所需的交叉频率和电网电流控制器的所需相位裕度。之后，假设一个目标函数，优化问题被公式化，通过最小化总电容和电感以及最小化滤波器纹波含量来最小化滤波器的物理尺寸。因此，所提出的目标函数最小化了滤波器物理尺寸和滤波器功率损耗，从而提高了滤波器的效率。原型演示并通过实验验证了所提出的滤波器设计和分析。