小电流接地系统单相接地故障选线方法的研究

针对小电流接地系统中的故障选线问题,指出了利用暂态量进行故障选线的研究方法。利用小波包的良好的频域分频特性,通过比较各线路暂态零序电流在所确定的频段下的小波包重构的高频分量的极性来实现故障选线。针对电压过零值附近时,该方法容易误判,应用小波奇异性检测功能,获取故障引起的电压、电流突变量的极性和大小来选线。两种方法扬长避短,从而达到最佳选线目的。通过MATLAB仿真结果表明此方法可以准确地实现单相故障选线,为实际工程应用提供了理论指导。

The Research on the Line Selection of Single-phase Fault in Trickle Earthed System

In view of the fault line selection in the neutral indirectly grounded system,the author proposes the issues of the application of the transient component in the fault line selection.By using the wavelet packets,with the advantage of time-frequency,based on the principle that the fault line's phase of transient capacity current are different from normal line's,the fault-line will be found out by contrasting polarity of each line's wavelet packet decomposition coefficient in characteristic bands.In order to ...