一种基于消弧线圈接地系统的选线方法与实现

A Method of Line Selection Based on Arc Suppression Coil Grounding System and Its Implementation

本文以消弧线圈调挡前后配电网各出线首端零序电流相位的变化,建立接地故障的选线技术路线,提出接地故障发生时将消弧线圈档位从正常工作的过补偿档位(档位1)调节至短时间欠补偿档位(档位2),接地故障所在的线路其零序电流相位变化最大。在仿真模型中,通过改变接地点的过渡电阻,分别在金属接地经200Ω电阻接地、经2000Ω电阻接地,获得了不同状态下的试验数据。结果表明本文所述选线方法,可明显区分接地线路与非接地线路,提高经消弧线圈接地的配电网接地故障的选线准确率。

The technical route of ground fault line selection is established in this paper based on the changes of the zero sequence current phase at the head end of each line in distribution network before and after the tap adjustment of arc suppression coil.It is proposed that if the gear of arc suppression coil is adjusted from the over-compensation gear(gear 1) in normal operation to the shortterm under-compensation gear(gear 2) when a ground fault occurs,the change of the zero sequence current phase of the line where the ground fault is located will be the largest.In the simulation model,by changing the transition resistance of the ground point,the test data under different conditions including the metal grounding,the 200Ω resistance grounding,and the 2 000 Ω resistance grounding are obtained.The results show that the line selection method proposed in this paper can clearly distinguish grounded and ungrounded lines and improve the line selection accuracy of ground fault in distribution networks grounded via arc suppression coils.