计及风电场侧谐波阻抗影响的谐波发射水平评估

风机滤波器和无功补偿装置导致风电场侧谐波阻抗并非远大于系统侧谐波阻抗,因此在计算风电场侧谐波电压发射值时,不可忽略风电场侧谐波阻抗的影响。提出一种基于改进复线性回归方程的风电场谐波发射水平评估方法。从公共连接点(PCC)谐波电压中分解出与回归方程系数无关的风电场谐波电流分量,据此建立复线性回归方程,采用复最小二乘法计算系统侧谐波阻抗,计及风电场侧谐波阻抗计算风电场侧谐波发射水平。针对风电场集电网络拓扑结构的多变性,提出一种集电网络聚合等值方法,将混联结构的集电网络聚合为T形结构的网络计算风电场侧谐波阻抗,并利用分散参数的误差边际效应对误差进行分析。仿真和实测数据验证了所提方法的有效性。

Assessment of harmonic emission level considering influence of harmonic impedance of wind farm

Wind turbine filter and reactive power compensation device lead to the result that the harmonic impedance of wind farm is not much larger than that of the utility, so the influence of harmonic impedance of wind farm should not be neglected when calculating harmonic emission value of wind farm. A method based on the improved complex linear regression equation is proposed for assessing the harmonic emission value of wind farm. The harmonic current components of wind farm side, which are not related with the regression equation coefficients, are separated from the harmonic voltage of PCC(Point of Common Coupling). Accordingly, a complex linear regression equation is established. The utility harmonic impedance is calculated by complex least square method. Considering the harmonic impedance of wind farm, the harmonic emission value is calculated. For the topology variability of wind farm feeder network, an equivalent and aggregation method for feeder network is proposed, by which, the hybrid feeder network is aggregated into T-shaped network to calculate the harmonic impedance of wind farm. The error marginal effect of dispersion parameters is used to analyze error. Simulation and measured data verify the effectiveness of the proposed method.