中性点非有效接地系统单相接地选线技术分析

中国的6kV～66kV配电网广泛采用中性点非有效接地方式,而中性点非有效接地系统单相接地故障选线问题长期以来没有得到很好的解决。针对这一现状完整地归纳了现有的各种选线技术,在阐述选线原理的同时分析了它们的适用条件,并结合现场故障录波数据分析各种选线技术的实际应用效果。分析结果表明,利用故障零序稳态信号进行连续选线的效果要优于其他方法。为了提高选线准确性,提出应充分发挥选线技术之间的互补性,将多种选线技术进行智能化融合。在此基础上,提出选线装置应进一步向准确故障定位的方向发展。

ANALYSIS OF THCHNOLOGY OF FAULT LINE SELECTION FOR SINGLE-PHASE-TO-EARTH FAULTS IN NEUTRAL POINT NON-EFFECTIVELY GROUNDED SYSTEM

The neutral point non-effectively grounded manner is widely applied in the power distribution systems of 6 kV to 66 kV in China. But the problem of line selection of single-phase-to-earth fault in the neutral point non-effectively grounded system has not been well settled for a long time. In accordance with this situation, this paper thoroughly summarizes all the present line selection techniques, analyzes their applicable conditions while expatiating the principle of line selection, and in combination of the field fault recording data, analyzes the practical application effects of the line selection techniques. The result of analysis indicates that the continuous line selection with the zero-sequence steady signals of the fault can obtain a better result than other approaches. To improve the accuracy of the line selection, this paper proposes that complementarities among the techniques of line selection be taken full use of and multifold techniques of line selection be amalgamated in an intelligentized way. And based on this, this paper proposes to develop the devices of line selection further towards accurate fault location.