The method of reducing single-phase grounding short-circuit current of small current grounding system through installing arc-suppression coil may result in failure of fault line selection device. The paper introduced a method of fault line selection in distribution network based on transient zero sequence component. The method uses dblO wavelet packet to decomposition transient zero sequence current flowing through every feeder line when the fault occurs, finds two feature bands with the largest and the second largest energy, and makes correlation analysis between wavelet packet decomposition coefficients of the two bands, so as to select the fault line. It took system with neutral grounding via arc suppression coil as an example to build simulation model, and made simulation experiment of grounding fault in both overhead line and cable. The experimental results demonstrated effectiveness of the method.%针对小电流接地系统通过装设消弧线圈来减小单相接地短路电流的方法可能造成已有选线装置失效的问题,介绍了一种基于暂态零序分量的配电网选线方法.该方法采用db10小波包对故障时刻流经每条馈线的暂态零序电流进行分解,找到能量最大和次大的两个特征频带,并对两个频带上小波包分解系数进行相关分析,从而选出发生故障的线路.以中性点经消弧线圈接地系统为例建立了仿真模型,并分别对架空线接地故障和电缆线接地故障进行了仿真实验.实验结果证明了该方法的有效性.
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