Power distribution systems are experiencing a large-scale integration of Converter-Interfaced Distributed Energy Resources (CIDERs). This complicates the analysis and mitigation of harmonics, whose creation and propagation are facilitated by the interactions of converters and their controllers through the grid. In this paper, a method for the calculation of the so-called Harmonic Power-Flow (HPF) in three-phase grids with CIDERs is proposed. The distinguishing feature of this HPF method is the generic and modular representation of the system components. Notably, as opposed to most of the existing approaches, the coupling between harmonics is explicitly considered. The HPF problem is formulated by combining the hybrid nodal equations of the grid with the closed-loop transfer functions of the CIDERs, and solved using the Newton-Raphson method. The grid components are characterized by compound electrical parameters, which allow to represent both transposed or non-transposed lines. The CIDERs are represented by modular linear time-periodic systems, which allows to treat both grid-forming and grid-following control laws. The method's accuracy and computational efficiency are confirmed via time-domain simulations of the CIGR\'E low-voltage benchmark microgrid. This paper is divided in two parts, which focus on the development (Part I) and the validation (Part II) of the proposed method.

中文翻译：

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具有转换器接口分布式能源的多相电网谐波潮流研究，第 I 部分：建模框架和算法

配电系统正在经历转换器接口分布式能源 (CIDER) 的大规模集成。这使谐波的分析和缓解变得复杂，谐波的产生和传播是由转换器及其控制器通过电网的交互作用促进的。在本文中，提出了一种使用 CIDER 计算三相电网中所谓谐波潮流 (HPF) 的方法。这种 HPF 方法的显着特征是系统组件的通用和模块化表示。值得注意的是，与大多数现有方法相反，谐波之间的耦合被明确考虑。HPF 问题是通过将网格的混合节点方程与 CIDER 的闭环传递函数相结合来制定的，并使用 Newton-Raphson 方法求解。网格组件的特点是复合电气参数，允许表示转置或非转置线。CIDER 由模块化线性时间周期系统表示，它允许处理网格形成和网格跟随控制规律。该方法的准确性和计算效率通过 CIGR\'E 低压基准微电网的时域仿真得到证实。本文分为两部分，重点介绍所提出方法的开发（第一部分）和验证（第二部分）。通过 CIGR\'E 低压基准微电网的时域仿真证实了其准确性和计算效率。本文分为两部分，重点介绍所提出方法的开发（第一部分）和验证（第二部分）。通过 CIGR\'E 低压基准微电网的时域仿真证实了其准确性和计算效率。本文分为两部分，重点介绍所提出方法的开发（第一部分）和验证（第二部分）。