基于负序电压变化量的灵活接地配电网永久性单相接地故障定位

针对灵活接地配电网，提出一种基于负序电压变化量的灵活接地配电网永久性单相接地故障定位方法。首先基于并联小电阻投入前后的负序电压变化量确定故障区域，其次根据零序电流修正投影比例系数判断故障分支从而确定故障区段，然后利用负序电压变化量测量值与计算值之间的偏差计算故障概率，对比故障区段内各个虚拟节点的故障概率进行精确定位，同时提出一种适用于该区段定位方法的测量点优化布置方案。最后利用PSCAD搭建仿真模型，仿真数据分析验证了所提永久性单相接地故障定位方法的有效性及可靠性。

Permanent single-phase grounding fault location in flexible grounding distribution network based on negative-sequence voltage variation

Aiming at the flexible grounding distribution network, a permanent single-phase grounding fault location method in flexible grounding distribution network based on negative-sequence voltage variation is proposed. Firstly, the fault area is determined based on the change of negative-sequence voltage before and after the parallel small resistance is set. Secondly, the fault branch is determined according to the modified projection proportion coefficient of zero-sequence current to determine the fault section. Then, the fault probability is calculated by using the deviation between the measured value and the calculated value of negative-sequence voltage change, and the fault probability of each virtual node in the fault section is compared for accurate fault location. At the same time, an optimal layout scheme of measuring points suitable for the location method of this section is proposed. Finally, PSCAD is used to build a simulation model, and the simulation data analysis verifies the effectiveness and reliability of the proposed permanent single-phase grounding fault location method.