背景谐波阻抗变化情况下的谐波责任划分

Harmonic contributions determination on condition of changing background harmonic impedance

在实际电力系统中负荷的投切会改变系统谐波阻抗,现有基于背景谐波阻抗恒定的谐波责任划分方法并不适用。文章定量研究了背景谐波阻抗变化情况下的谐波责任划分,根据背景谐波阻抗变化时谐波电压和谐波电流之间的关系,提出斜率比较法辨识背景谐波阻抗变化的时间点,以此对样本数据进行分段处理,实现数据的自适应分段。在相同段内采用几何平均回归,实现背景谐波阻抗的准确估计,并完成谐波责任的分段划分。同时,定义了背景谐波阻抗变化情况下的总谐波责任指标来更有效地衡量用户的谐波责任大小。在诺顿等效电路中对本文方法进行仿真分析,并与传统方法进行比较,验证了文中方法的有效性和准确性。

In practical power system,background harmonic impedance often changes owing to switching loads,and the present researches on the harmonic contributions determination based on constant background harmonic impedance are not applicable in this case. The paper studies the determination of harmonic contributions on condition of changing background harmonic impedance. The slope comparison method,which adopts the relationship of harmonic voltage and harmonic current,is proposed to segment the sample data adaptively. In the same segment,geometric mean regression is adopted to estimate the background harmonic impedance accurately. Thus,the segmental harmonic contributions are determined. Additionally,a total harmonic contribution index is established to effectively measure the harmonic contribution of customer.Simulations are carried on the simple Norton-equivalent circuit to validate the proposed method,and the proposed method is compared with traditional methods,which prove the effectiveness and accuracy of the method.