This paper presents a new Transfer Function (TF)-based approach to evaluate the summation of complex harmonic and interharmonic current primary emissions in a wind power plant. A comprehensive impedance modeling of a doubly-fed induction generator including the Phase Locked Loop (PLL), induction generator, and current control loops of the converters is included in the TFs. A small-signal impedance modeling consisting of positive/negative-sequence modeling up to 50th harmonic order is adopted. The updated TF models are then used to calculate the contribution of each wind turbine to the total harmonic and interharmonic current distortions at the point of interconnection. Three phase angle distribution patterns are also presented to assess the stochastic behavior of the harmonic and interharmonic currents using the concept of “aggregation factor”. The variations of the aggregation factor with the PLL bandwidth are also investigated. Besides, the obtained primary emission TFs are used to adjust α-exponent in IEC 61000-3-6 summation rule. Analytical results are presented and compared to the simulation results where it is concluded that the proposed approach is more accurate than the previous approaches of TF modeling and related phase angle distribution patterns.

本文提出了一种新的基于传递函数 (TF) 的方法来评估风力发电厂中复杂谐波和间谐波电流初级排放的总和。TF 中包含双馈感应发电机的综合阻抗建模，包括锁相环 (PLL)、感应发电机和转换器的电流控制回路。采用由高达 50 次谐波阶次的正/负序建模组成的小信号阻抗建模。然后使用更新的 TF 模型计算每个风力涡轮机对互连点处的总谐波和间谐波电流失真的贡献。还提出了三相角分布模式，以使用“聚合因子”的概念评估谐波和间谐波电流的随机行为。还研究了聚合因子随 PLL 带宽的变化。此外，获得的初级发射TFs用于调整IEC 61000-3-6 求和规则中的α-指数。给出了分析结果，并与仿真结果进行了比较，得出的结论是，所提出的方法比以前的 TF 建模方法和相关的相角分布模式更准确。