【作者】 靳智强； 张艳霞； 方廷； 石勇；

【Author】 Jin Zhiqiang,Zhang Yanxia,Fang Ting,Shi Yong (School of Electrical Engineering and Automation,Tianjin University,Tianjin 300072,China)

【机构】 天津大学电气与自动化工程学院；

【摘要】 我国的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),其接地选线问题成为长期困扰实际运行的技术难题。通过用小波包重构算法分析了B相接地故障时的A、C相突变电流,提出了用A、C两相突变电流之和的暂态特征实现B相接地的故障选线方法。利用频域和时域相结合的分析方法,提出了A相或C相接地时,构造B相电流并合成较精确的、能用于选线的零序电流的方法。结合课题组已取得的研究成果,形成了一整套针对两相TA配电网单相接地故障的新的选线方法。该方法不受中性点接地方式和系统正常运行时不平衡电流的影响,解决了现场的实际运行需要。ATP仿真和试验结果验证了所提出的选线方法的可靠性和有效性。更多还原

【Abstract】 In China,current transformers(TAs)are just installed at A-phase and C-phase in most distribution networks with neutral indirectly grounding networks.It has been a very difficult problem for a long time to identify faulted line,when single phase to ground fault(SGF)occurs.After analyzing the mutational current of A-phase and C-phase when B-phase grounding fault occurs with wavelet package reconstruction algorithm,the fault line detection algorithm actualized by using the transient characters of the sum of A-phase mutational current and C-phase mutational current is proposed.Through the analysis in frequency domain and time domain,the algorithm of producing B-phase transient current and furthermore obtaining the exact zero-sequence current,which can be used in fault line detection when A-phase to ground fault or C-phase to ground fault occurs,is founded out.Furthermore,with the former research production of our group,a new integrated algorithm used to identify single phase to ground fault line in two TAs distribution networks is represented.The algorithm is independent of the mode of neutral grounding and the unbalanced current under normal operation condition.It can satisfy the requirement of fault line selection in field operation.The ATP simulations and experiments verify the validity and reliability of the proposed algorithm.更多还原