含DG的小电流接地系统单相接地故障定位

发布时间：2018-07-07 22:11

本文选题：分布式电源 + 小电流接地系统　；参考：《电机与控制学报》2014年08期

【摘要】：对比分析含分布式电源(DG)与不含DG的小电流接地系统在发生单相接地故障时暂态零序电流的特点,得出DG的加入不影响各线路的暂态零序电流分布。因暂态零序电流中存在多个频率分量,虽然对于某一频率而言,故障线路与健全线路电流相位(方向)相反,但多个频率的叠加会使得这样的方向性变得模糊。采用小波变换的Mallat算法对各线路的暂态零序电流进行分解和重构,从而获得低频逼近部分aN和高频细节部分dN。据此,提出选线判据:对于含DG的小电流接地系统,在暂态零序电流的初始阶段,故障线路暂态零序电流的细节分量幅值是所有健全线路的幅值之和,相位与健全线路相反。最后,建立仿真模型,对含DG的中性点经消弧线圈接地系统和中性点不接地系统进行了仿真实验,实验结果证明该方法故障判别准确,选线灵敏度高,实用性强。
[Abstract]:The characteristics of transient zero sequence current in a single phase grounding fault containing distributed power supply (DG) and DG are compared and analyzed. It is concluded that the addition of DG does not affect the transient zero sequence current distribution of each line. Because there are multiple frequency components in the transient zero sequence current, the fault line and the sound line are for a certain frequency. The current phase (direction) is opposite, but the superposition of multiple frequencies will make the directivity become blurred. The Mallat algorithm of wavelet transform is used to decompose and reconstruct the transient zero sequence current of each line, thus the low frequency approximation part of aN and the high frequency detail dN. are obtained, and the line selection criterion is proposed: for the small current grounding system containing DG, In the initial phase of the transient zero sequence current, the amplitude of the transient zero sequence current of the fault line is the sum of the amplitudes of all the sound lines, and the phase is opposite to the sound line. Finally, the simulation model is established, and the simulation experiments are carried out on the neutral point of the grounding system and the neutral point ungrounded system with DG neutral point, and the experimental results prove that the formula is used. The method has the advantages of accurate fault identification, high sensitivity and high practicability.
【作者单位】：上海电力学院自动化工程学院;福建省电力有限公司检修分公司;
【基金】：国家高技术研究发展计划(863计划)(2011AA05A106)
【分类号】：TM862

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