基于故障分量的配电网接地选线技术的研究

配电线路一般不经过交叉换位，线路结构参数和负荷常常是不对称的，因此在正常运行时，系统中存在不平衡的零序电流。当正常运行零序电流较大时，可能“淹没”因为接地所引起的零序电流，增加了故障信息提取的难度，影响接地选线的准确性和可靠性，而零序电流故障分量既充分包含了接地的故障信息，又能有效排除系统正常零序电流的影响，在理论分析和故障仿真的基础上，提出了利用零序电流故障分量进行接地选线的原理，仿真计算说明利用零序电流故障分量进行接地选线具有更高的准确性和可靠性，不受系统结构参数和负荷不对称的影响，可以适用于中性点不同接地方式系统的接地选线。

Study on the technology which fault line is selected to check fault in distribution network based on the fault component

There often exists unbalance zero-sequence current in distribution network while normal running due to the asymmetry of line construction parameter and load, and also uncross-transposition of distribution lines. The zero-sequence fault current normally includes operating zero-sequence current and fault component of zero-sequence current, and the zero-sequence current caused by earthed will be difficult to sense it when normal running zero-sequence current is larger, which would make it difficult to pick up fault information and influence the accurate and reliable choice of fault line. The fault component of zero-sequence current not only includes fault information of earthing, but also can efficiently decrease the effect of normal zero-sequence current on fault check.. The principle that uses fault component of zero-sequence current to select fault line was presented in the paper based on the theoretical analysis and fault simulation, the results of simulating calculation showed that using the fault component of zero-sequence current as a key to fault line selection seemed to be more accurate and reliable, which was not affected by the asymmetry of system structure parameter and load and suitable for choosing fault line for different earthing ways of neutral point.