基于区间约束的主谐波电流来源判别方法

摘要

针对流过线路元件的谐波电流难以明确来源的问题,提出一种基于区间约束的公共连接点(PCC)主谐波电流来源判别方法.在谐波诺顿等效电路的基础上,分析得出谐波有功功率方向法在一定的区间内是可以完全正确有效的.通过PCC处测量的谐波电压和电流信息,利用电路基本原理和严格不等式约束条件及谐波电流指标基本准则,讨论系统侧和用户侧谐波阻抗基本性质的各类情况,推导得出:主谐波电流来源为用户侧的情况仅根据谐波电压和电流的相角差就可直接判别;主谐波电流来源为系统侧的情况,将两者相角差和简单阻抗条件相结合进行判别.通过多种实际工程场景的测量数据验证了所提方法是正确和有效的.%Since the source of harmonic current flowing through the transmission line is difficult to distinguish,an identification method for main source of harmonic current at the PCC(Point of Common Coupling) is proposed based on boundary restriction.On the basis of Norton equivalent circuit of harmonic,it is deduced that the harmonic active power direction method is completely correct and effective in a certain range.According to the harmonic voltage and current information measured at PCC,various essential properties of harmonic impedance at both system and user sides are discussed by basic circuit principles,strict inequality restrictions and basic rules of harmonic current index,which deduces that,the situation that harmonic current mainly origins from user side can be directly identified by the phase angle difference between harmonic voltage and current,while the situation of the system side can be identified by the combination of the phase angle difference and simple impedance conditions.The correctness and effectiveness of the proposed method are verified by measurement data of several practical engineering scenarios.