基于零序电流特性的中性点灵活接地系统的故障选线方法  

Fault Line Selection Method for Neutral Flexible Grounding System Basedon Zero Sequence Current Characteristics

作　　者：黄亚峰[1] 王浩天 朱登宝 李梦娇 孙博延 HUANG Yafeng;WANG Haotian;ZHU Dengbao;LI Mengjiao;SUN Boyan(Electrical Engineering College,Northeast Electric Power University,Jilin Jilin 132012)

机构地区：[1]东北电力大学电气工程学院,吉林吉林132012

出　　处：《东北电力大学学报》2023年第3期16-22,71,共8页Journal of Northeast Electric Power University

基　　金：国家电网公司智能电网联合基金项目(U1866601)。

摘　　要：在配电网小电流接地系统中,当发生单相接地故障时线路零序电流信号十分微弱,尤其是高阻接地故障时难以进行准确选线。文中提出了基于新型中性点灵活接地的配电网故障选线新方案,该选线方法在发生单相故障时通过高速电力电子开关在中性点投入小电阻接地支路,将小电流接地系统供电可靠性和大电流接地系统信号明显等优点结合起来,利用零序电流幅值以及并入小电阻前后零序电流相位差的变化作为判据,有效解决了在高阻接地情况下选线不理想的现状,实现配电网故障准确选线。利用PSCAD/EMTDC仿真环境对配电网进行单相接地故障模拟,仿真结果表明在不同故障情况下所提方案具有良好的可靠性和有效性。In low-current grounding system of distribution network,the zero-sequence current signal is very weak when single-phase grounding fault occurs,especially when high-resistance grounding fault occurs,it is difficult to accurately select the line.In this paper,a new method of fault line selection for distribution network based on flexible grounding of new neutral points is proposed.When single-phase fault occurs,a high-speed power electronic switch is used to put in a small resistance grounding branch at the neutral point,which combines the advantages of power supply reliability of small current grounding system with obvious signal of large current grounding system.Using the amplitude of zero sequence current and the change of phase difference of zero sequence current before and after incorporating small resistance as the criterion,the unsatisfactory situation of line selection under the condition of high resistance grounding is effectively solved,and the accurate line selection of distribution network fault is realized.PSCAD/EMTDC simulation environment is used to simulate single-phase grounding fault of distribution network,and the simulation results show that the proposed scheme has good reliability and effectiveness under different fault conditions.

关 键 词：小电流系统 灵活接地 故障选线 单相接地故障 零序电流 

分 类 号：TM930[电气工程—电力电子与电力传动]