摘要
现有小电流接地故障选线方法均以辐射状线路为基础,特定情况时将出现同母线环路供电情况,接地故障特征将发生变化,已有选线方法需要重新审视。文中建立了含环路配电网单相接地故障复合网络,推导了环路两端出口稳态与暂态零序电流的分布特征,分析了已有选线方法的适应性。结果表明,环路接地时,随线路参数和故障位置不同,环路两端出口电气量并非始终表现为故障线路特征,已有稳态量和暂态量选线方法将可能出现误选与漏选。可通过增加备选线路条数并利用环路中一条出口线路切除前后其余各线路零序导纳的变化辨识故障线路或将环路两端出口零序电流之和参与选线比较的方法解决该问题。仿真与现场数据验证了故障特征的正确性及所提选线措施的有效性。
The existing line selection technologies of small current grounding fault are all based on radiating lines.However,the case of bus line loop will appear under certain circumstances,and then the characteristics of the grounding fault will change,which means the existing line selection methods need to be updated.In this paper,a compound network of single-phase grounding fault in distribution network with loop is established.After then,the distribution characteristics of the steady and transient zero-sequence currents at the end of the loop are derived,and the adaptability of the existing line selection methods is analyzed.The results show that,in the case of loop grounding,with the difference of the line parameters and the location of the fault,the electrical quantity at the two ends of the loop does not always appear as the characteristics of the fault line.In the situation,existing steady and transient line selection techniques may cause mistake in line selection.The problem can be solved by increasing the number of alternative lines and using the change of each remaining line’s zero-sequence admittance,before and after the resection of an exit line in the loop,to identify the fault line.And it can also be solved by taking the sum of the zero-sequence currents at both ends of the loop into the line selection comparison.Simulation and field data verify the correctness of the fault characteristics and the effectiveness of the line selection methods.
作者
郭雨豪
薛永端
徐攀
俞小勇
徐丙垠
GUO Yuhao;XUE Yongduan;XU Pan;YU Xiaoyong;XU Bingyin(College of Information and Control Engineering,China University of Petroleum (East China),Qingdao 266580,China China Electric Power Research Institute (Nanjing),Nanjing210003,China;Electric Power Research Institute of Guangxi Power Grid Co.Ltd.,Nanning 530023,China;Research Center for Smart Grid,Shandong University of Technology,Zibo 255049,China)
出处
《电力系统自动化》
EI
CSCD
北大核心
2019年第1期234-241,共8页
Automation of Electric Power Systems
基金
国家自然科学基金资助项目(51477184)
中国南方电网有限责任公司科技项目(GXKJXM20151029)~~
关键词
小电流接地系统
接地故障
环路运行
故障特征
故障选线
small current grounding system
grounding fault
loop-closed operation
fault characteristic
fault feeder selection
