仅利用零序电流的谐振接地系统接地故障方向算法  

Grounding Fault Direction Algorithm Using Zero-sequence Current in Resonant Grounding System

作　　者：金鑫[1] 薛永端[1] 彭振华 杨帆 徐丙垠 JIN Xin;XUE Yongduan;PENG Zhenhua;YANG Fan;XU Bingyin(College of New Energy,China University of Petroleum(East China),Qingdao 266580,China;Nanchang Power Supply Company,State Grid Jiangxi Electric Power Co.,Ltd.,Nanchang 330000,China;Electric Power Research Institute of State Grid Hubei Electric Power Co.,Ltd.,Wuhan 430077,China;Shandong Kehui Power Automation,Zibo 255087,China)

机构地区：[1]中国石油大学(华东)新能源学院,山东省青岛市266580 [2]国网江西省电力有限公司南昌供电分公司,江西省南昌市330000 [3]国网湖北省电力有限公司电力科学研究院,湖北省武汉市430077 [4]山东科汇电力自动化股份有限公司,山东省淄博市255087

出　　处：《电力系统自动化》2020年第9期164-170,共7页Automation of Electric Power Systems

基　　金：国家自然科学基金资助项目(51477184)。

摘　　要：由于多数终端难以获得零序电压或三相电压信号,限制了暂态功率方向法在小电流接地故障定位、多级保护、分界技术的应用。分析了谐振接地系统单相接地时故障点上游与下游的零序电流工频分量、暂态主谐振分量以及衰减直流分量与故障初相角的关系,发现可利用零序电流工频分量作为零序电压的极化相量,进一步识别故障方向。当零序电流工频分量初相位分别在(-45°,75°)或(135°,255°)以内,暂态主谐振分量初相位分别在(-30°,30°)或(150°,210°)以内时,或者衰减直流分量与工频分量幅值之比大于预设门槛时,故障方向为正,否则故障方向为负。仿真和现场实际故障数据验证了算法的正确性。Most distribution terminals are difficult to obtain zero-sequence voltage or three-phase voltage signals. So the application of transient power direction method in fault location, multi-level protection and demarcation of single-phase grounding fault in resonant grounding system is limited. The relationship of the initial phase angle with different components of zero-sequence current of fault points on upstream and downstream, with single-phase grounding fault in resonant grounding system, is analyzed. The components could be power frequency component, transient main resonance component or decaying DC component. It is found that the power frequency component of zero-sequence current can be used as the polarization phasor of the zero-sequence voltage,to further identify the fault direction using zero-sequence current only. The fault direction is positive, when the phase of power frequency component is within(-45°, 75°) and the phase of transient main resonant component is within(-30°, 30°), or the phase of power frequency component is within(135°, 255°) and the phase of transient main resonant component is within(150°, 210°), or the ratio of the amplitudes of decaying DC component to power frequency component is greater than the preset threshold.Otherwise, the fault direction is opposite. Both the simulation and the field fault data verify the correctness of the proposed method.

关 键 词：谐振接地系统 单相接地故障 极化相量 故障方向 

分 类 号：TM862[电气工程—高电压与绝缘技术]