配网馈线接地定位及环供支线接地选线判据探讨

Criterion Discussion of Distribution Feeder Grounding Location and Ring Feeder Grounding Line Selection

分析了不同接地方式下的接地电流特征及接地故障线路的过渡过程,并根据该过渡过程提出利用换路瞬间首个脉冲方向的定位/选线判据。该判据适用于不接地系统、消弧线圈接地系统的接地定位/选线,不受电压相位角的影响,不依赖零序电压,判据单一,接线简单。对该判据在各种故障情况下的应用进行了详细的分析。依照此判据实现的小电流接地选线装置的实际运行效果表明了该判据的准确性和实用性。

The characteristics of grounding current under various grounding methods and the transient process of ground- fault line are analyzed. A criterion for grounding location / line selection using the first pulse direction of the moment when the circuit is switched is proposed according to the transient process. This criterion is suitable for grounding location / line selection of isolated neutral system and arc suppression coil grounding system. It is not affected by voltage phase angle and doesn＇t depend on zero- sequence voltage with single criterion and simple wiring. A detailed analysis on the criterion application in various faults is carried out. The accuracy and practicability of the proposed criterion is proved by the actual perfect application results of small current grounding line selection device taking the advantages of this criterion.