The increasing number of non-linear loads causes a severe harmonic problem in low voltage power network. The distributed generations (DGs) not only integrate renewable energy sources into utilities, but also provide an effective way for harmonic suppression. Based on the different wiring modes of three-phase asymmetric load, a harmonic compensation control method using single-phase DGs is presented. Firstly, the wiring modes and load conditions of typical harmonic source are analyzed. Byequalizing the asymmetric load into star with or without neutral line and delta wiring modes, the distribution of the harmonic current is discussed and the harmonic compensation function is derived. On the basis, the harmonic component of each phase load and circuit is extracted depending on the time delay and synchronous frame transform, and the harmonic compensation control scheme of single-phase DGs is established. Finally, the simulation results verify the effectiveness of the presented method to harmonic suppression by means of Matlab/Simulink.%非线性负荷不断增加导致台区电网的谐波问题愈加严峻,而越来越多分布式发电(DG)接入在实现新能源就地并网的同时,也为台区电网的谐波治理提供了一个有效途径.以含单相DG的台区电网为对象,考虑三相不对称负荷的接线方式差异,提出了一种利用单相DG的分相谐波补偿控制策略.首先对含单相DG的台区电网接线方式和典型台区谐波源负荷情况进行分析,将不对称负荷等值成星形有中性线、星形无中性线和三角形接线方式,分别讨论了台区电网的谐波电流分布,进而推导了单台和两台单相DG接入时的谐波电流补偿函数.据此,采用基于延时环节和同步坐标变换的谐波电流检测方法,提取各相负荷电流和线路电流的谐波分量,建立不同接线方式下单相DG的谐波补偿控制方案.最后,利用Matlab/Simulink验证了所提的分相谐波补偿控制对台区电网谐波的治理效果.
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