摘要
充分利用故障暂态信息可有效提高谐振接地系统故障选线的准确率,提出一种利用零序阻抗相频特性差异的选线方案。谐振接地系统单相接地故障后零序阻抗具有一定特征,健全馈线零序阻抗在任意频段内均为容性;故障馈线零序阻抗在低频段内为感性,高频段内为容性。根据该特征构建不同频段下馈线零序阻抗角离散度分析法。分析可知健全馈线在不同频段下的零序阻抗角的离散度较小;故障馈线在不同频段下的零序阻抗角的离散度较高,尤其在高频与低频下的零序阻抗角差值接近180°,据此构建故障选线判据。仿真结果表明,该方法在高阻接地时依然有效,与传统选线方法相比,该方法进一步提高了选线准确率与可靠性。
Make full use of fault transient information can improve effectively the accuracy of fault line selection in resonance earthing system.In this paper,a kind of line selection scheme using the difference in phase-frequency characteristics of zero-sequence impedance is proposed.The zero-sequence impedance after the fault of the single-phase earthing system of the resonant earthing system has a definite feature.The zero-sequence impedance of sound feeder is capacitive at any frequency band,while,the zero-sequence impedance of fault feeder is inductive at low frequency band,and capacitive in high frequency band.The dispersion analysis method is constructed of zero-sequence impedance angle of feeder at various frequency bands in accordance with above feature.It is known by the analysis that the dispersion of the zero-sequence impedance angle of the sound feeder is smaller and that of the faulty feeder is higher,particularly,the difference of zero-sequence impedance at high and low frequencies approaches 180 degree.On this basis,the criteria of fault line selection are constructed.It is shown by the simulation result that the method is still effective in high impedance earthing and,compared with the traditional line selection method,improves the accuracy and reliability of line selection.
作者
王丹
白杰
张昭
周宁
闫群民
WANG Dan;BAI Jie;ZHANG Zhao;ZHOU Ning;YAN Qunmin(School Key Laboratory of Industrial Automation,Shaanxi Hanzhong 723001,China;State Grid Shaanxi Electric Power Company Yulin Power Supply Company,Shaanxi Yulin 719000,China;Shaanxi Local Power(Group)Company Baoji Power Supply Branch,Shaanxi Baoji 721004,China)
出处
《电力电容器与无功补偿》
2021年第2期146-152,共7页
Power Capacitor & Reactive Power Compensation
基金
陕西省教育厅重点实验研究计划项目(20JS018)。
关键词
谐振接地系统
故障选线
相频特性
零序阻抗角
离散度分析
resonant earthing system
fault line selection
phase frequency characteristics
zero-sequence impedance angle
dispersion analysis
