两相电流互感器配电网零序电流构造方法  

Construction Method of Zero-sequence Current in Distribution Networks with Two Phase’Current Transformers

作　　者：方廷[1] 张艳霞[1] 靳智强[1] 

机构地区：[1]天津大学电气与自动化工程学院,天津市300072

出　　处：《电力系统自动化》2007年第9期61-67,共7页Automation of Electric Power Systems

摘　　要：中性点非直接接地配电网大多只安装A,C两相电流互感器(TA),而现有单相接地故障选线方法基本都以零序电流为基础实现。如何在两相TA配电网中准确检测并隔离接地故障线路,成为长期困扰实际运行的技术难题。通过对暂态电流的频域和时域分析,找出B相暂态电流与A,C相暂态电流的对应关系,提出在A相和C相接地时由A相和C相暂态电流构造B相暂态电流,进而得到较精确零序电流的方法。通过大量仿真实验验证了所提出的构造方法的正确性。零序电流的成功构造为实现两相TA配电网单相接地故障选线提供了基础。In China, current transformers （TAs） are just installed at A-phase and C-phase in most non-solid earthed distribution networks. Most of the existing line-selection methods for single phase grounding fault are based on zero-sequence current. How to detect and separate the grounding-faulty line with two phases＇ TAs, has been a very difficult technical problem which affects practical operation. Through the analysis of transient currents in frequency domain and time domain, the relationship of A-phase, C-phase transient currents and B-phase transient current has been founded out. A method to produce B-phase transient current with A-phase and C-phase transient currents is proposed when A or C phase is earthed, and hence the exact zero-sequence current can be obtained. The results of simulation demonstrate the correctness of this method.

关 键 词：配电网 中性点非直接接地电网 单相接地故障 故障选线 暂态零序电流 

分 类 号：TM452[电气工程—电器]