基于动态接地方式的配电网单相接地故障区域隔离

Single-phase Grounding Fault Area Isolation inDistribution Network Based on Dynamic Grounding Method

中性点经消弧线圈接地配电网发生单相接地故障时,受消弧线圈调谐与过渡电阻的影响,导致故障选线和隔离困难,严重影响了人身安全与供电可靠性。为此,提出了一种基于动态接地方式的故障区域隔离方案,将消弧线圈接地改造为动态接地,对动态切换前后的各配电终端零序电流变化规律进行了理论分析,并提出节点零序电流比较法进行故障区段定位。现场试验验证了方案的准确性与可靠性,实现了0~4000Ω高阻接地故障下的区域隔离,为解决消弧线圈接地方式下的故障区段定位难题提供了工程应用案例。

When a single-phase grounding fault occurs in the distribution network where the neutral point is grounded by the arc suppression coil,it will be affected by the tuning and transition resistance of the arc suppression coil,resulting in difficulty in fault line selection and isolation,which will seriously affect personal safety and power supply reliability.Therefore,a fault area isolation scheme based on dynamic grounding method was proposed.The grounding of the arc suppression coil was changed into dynamic grounding.The variation law of the zero-sequence current of each distribution terminal before and after dynamic switching was theoretically analyzed.The sequence current comparison method was used to locate the fault section.The field test verified the accuracy and reliability of the scheme,and the regional isolation was realized under 0~4000Ωhigh-resistance grounding fault,which provided an engineering application case for solving the problem of fault section location under the grounding method of the arc suppression coil.