基于暂态零序电流变化率的小电流接地系统单相接地故障选线方法的研究钱虹.pdf

基于暂态零序电流变化率的小电流接地系统 单相接地故障选线方法的研究 钱 虹 黄正润 阮大兵 （上海电力学院电力与自动化工程学院，上海 200090 ） 摘要 首先，对小电流接地系统的单相接地故障进行仿真，分析故障后暂态零序电流的特征， 即在暂态初始阶段的暂态故障电流主要由暂态电容电流所决定，因此故障线路的暂态零序电流幅 值最大。若忽略暂态电感电流，则故障线路的暂态零序电流幅值等于所有健全线路的幅值之和， 且方向与非故障线路相反。因此，在求得各线路的暂态零序电流变化率后，通过比较它们的大小 和极性就能准确定位出故障线路。最后，采用Matlab 搭建仿真模型，对不同的电压初始相角、过 渡电阻、故障位置以及中性点的不同接地方式进行仿真实验。仿真结果证明该方法能够准确、迅 速地定位出故障线路，具有较强的可靠性、实用性。 关键词：小电流接地系统；故障选线；暂态零序电流；变化率 The Study of Fault Line Selection’s Method Based on the Change Rate of Transient Zero Sequence Current for Small Current Grounding System Qian Hong Huang Zhengrun Ruan Dabing (School of Electric Power and Automation Engineering of Shanghai University of Electric Power, Shanghai 200090) Abstract First of all, the simulation of one-phase grounding fault is made for the small current grounding system. And then analysis the characteristics of the transient zero sequence current. In the initial stages, the transient fault current mainly decided by the transient capacitance current, so the fault line transient zero sequence current’s amplitude is the largest. If you ignore the transient inductance current, then the fault line transient zero sequence current’s amplitude is equal to the sum of all sound lines’ amplitude. The direction of the fault line is opposite to all sound lines’. Therefore, after we obtain the change rate of transient zero sequence current for each line, we can locate the fault line accuracy by comparing the size and polarity of them. Finally, the simulation model based on Matlab is set up for different voltage initial phase angle, transition