基于改进导纳法的小电流接地系统接地故障选线方法

Improved neutral admittance method based grounding faulted feeder detection for power system with small current earthing

针对小电流接地系统单相接地故障时选线的难题,采用改进中性点导纳法对10kV配电网接地故障的故障特征进行研究分析;针对不同故障初相角、故障位置以及过渡电阻,研究各线路的零序电流和暂态故障分量变化情况。基于ATP-EMTP的仿真分析验证该改进中性点导纳选线方法的可行性,结果表明改进中性点导纳法可以避免因补偿系数变化等引起的故障区域和非故障区域的重叠问题。

In order to solve the problem of single-phase grounding faulted feeder protection for power system with small current earthing,the grounding fault characteristics were analyzed with improved neutral admittance method for a 10 kV distribution system in this paper.The zero-sequence current and fault signal transient components changing under different fault times,fault locations and fault resistances were investigated.ATP-EMTP based simulation analysis results verified the reliability of the improved neutral admittance method which can avoid the overlapping of the fault and non-fault region when the compensation coefficient changes.