基于中性点零序电流注入的高阻接地辨识方法  

High resistance grounding fault identification method with zero sequence current injection at neutral point

作　　者：张颖[1] 张宇雄[1] 容展鹏 韦梦[1] 凌晓峰[1] 

机构地区：[1]长沙理工大学电气工程学院,湖南长沙410004

出　　处：《电力科学与技术学报》2016年第3期123-129,共7页Journal of Electric Power Science And Technology

基　　金：国家自然科学基金(70871074)

摘　　要：小电流接地系统发生单相高阻接地故障时产生的零序电压与系统三相参数不平衡引起的零序电压相似,难以区分。通过跟踪测量系统正常运行时的对地导纳,当系统中性点零序电压变化时,向系统注入预定的零序电流,测量对应零序电压;根据电压变化前的对地导纳以及注入电流前后的零序电压推导出η的相位,实现高阻接地故障与系统三相不平衡的辨别;选取适当注入零序电流,可确保故障点电流不增加,避免故障点燃弧。Matlab/simulink仿真分析表明该方法能有效辨识单相高阻接地故障。The zero sequence voltage caused by single phase grounding fault with high resistance is similar to the voltage caused by unbalanced parameters of three-phase in the ineffectively grounded distribution system, they are difficult to distinguish. By measuring the admittance under normal operation system, when the zero sequence voltage at neutral point changed？ the predeter-mined zero sequence current was injected into the system, and the corresponding zero sequence voltage was measured. TheT） phase deduced by the admittance and zero sequence voltage could identify the high resistance grounding fault and the three-phase unbalance. The injection zero current was chosen suitably, which could ensure the fault point current didn＇t increase and avoid arcing fault. Matlab/simulink simulation analysis results show that this method can effectively identify the single-phase high-impedance grounding fault.

关 键 词：小电流接地系统 零序电流 高阻接地故障 三相不平衡电压 

分 类 号：TM773[电气工程—电力系统及自动化]