谐振接地系统高阻接地故障暂态选线与过渡电阻辨识

Faulty Feeder Selection and Transition Resistance Identification of High Impedance Fault in a Resonant Grounding System Using Transient Signals

对于小电流接地故障,传统分析方法认为暂态过程是在故障点虚拟电源激励下的零状态响应,故障线路出口的暂态电压与暂态电流反映的是背离故障点的背后健全线路阻抗特性,不能直接反映故障点电流及过渡电阻状态。文中分析谐振接地系统高阻接地故障暂态机理与暂态电气量特征,完善小电流接地故障暂态分析理论,提高高阻接地故障选线准确性,并为高阻接地故障的检测、补偿、过电压防护等技术提供基础。采用数字仿真和现场数据验证方法的可行性。

Traditional analysis of the transient process of single-phase earth faults in a non-solidly earthed network is considered as a zero-state response generated by the virtual voltage source at the fault point. The transient zero-sequence voltage and current of faulty feeder reflect the impedance characteristics of all the healthy feeders, and they cannot reflect the state of the current at the fault point and the transition resistance directly. The fault transient mechanism and characteristics of transient electric parameters of high impedance fault in a resonant grounding system was analyzed, and the accuracy of faulty feeder selection in high impedance faults was improved. And the paper provided basis for high impedance fault detection, compensation, and over-voltage protection technologies. The feasibility of the method was verified by simulation and field data.