五次谐波检测原理及其在矿井高压电网单相接地保护中的应用

Detection Principle of the Fifth Harmonic and Its Application in Single-phase Grounding Protection System of High-voltage Power Networks of Mine

为限制单相接地电流,在矿井高压电网中引入了消弧线圈,这使得现有接地保护的选择性性能受到了严重影响。在分析电网接地故障规律的基础上,阐述了适用于各种中性点接线方式电网的谐波检测原理。作为该原理的具体应用,介绍了一种基于五次谐波检测的井下高压选择性接地保护系统,并给出了试验结果。

The installed selective grounding protection equipment for underground high-voltage networks could not work properly owing to the application of the arc-suppression coil, by which the grounding current is compensated. On the basis of analyzing the ground faults, this paper expounded the protection principle based on the fifth harmonic detection, which is suitable for all kinds of underground high-voltage distribution networks. As the application example, a kind of selective single-phase grounding protection system for underground high-voltage distribution networks was introduced, and the result of the experiment was shown.