摘要
小电阻接地系统中发生单相高阻接地故障时,由于对地故障电流小,难以实现可靠的故障区段定位。利用对称分量法和电流分支系数对故障特征进行分析发现,故障点上游的故障相工频变化量电流要远大于健全相的,而故障点下游和健全线路的三相电流工频变化量幅值则相近。据此,提出了一种基于相电流工频变化量比值的高灵敏性故障区段定位方法。基于PSCAD/EMTDC进行了大量仿真测试,结果表明所提方法在过渡电阻达2000?时仍然能够可靠定位故障区段,且只需电流信息,易于工程实现。
When High-Impedance Grounded Faults(HIGFs)occur in Low-Resistance Grounded Systems(LRGSs),it is difficult to locate the fault reliably,because of its small fault current.Symmetrical components and a current branching coefficient are used to analyze the characteristics of three-phase current power frequency variations.The analysis shows that the current power frequency variation in the faulty phase of upstream fault points is much larger than that of healthy phases,while the current power frequency variations in the hree-phase of downstream fault points and healthy lines are approximately the same.From this,a highly sensitive HIGFs location method based on the phase current power frequency variation ratio is proposed.A large number of simulations developed on platform PSCAD/EMTDC indicate that the proposed method can locate the fault quickly and reliably,even when the fault impedance value reaches 2000Ω.It only uses the current signal,and this is easy to implement.
作者
廖芳群
李海锋
陈嘉权
梁远升
王钢
LIAO Fangqun;LI Haifeng;CHEN Jiaquan;LIANG Yuansheng;WANG Gang(School of Electric Power,South China University of Technology,Guangzhou 510640,China;Guangzhou Power Supply Bureau,Guangdong Power Grid Co.,Ltd.,Guangzhou 510620,China)
出处
《电力系统保护与控制》
CSCD
北大核心
2021年第21期150-158,共9页
Power System Protection and Control
基金
广东省自然科学基金项目资助(2021A1515010631)。
关键词
小电阻接地系统
高阻接地故障
对称分量法
电流分支系数
相电流工频变化量比值
low-resistance grounded system
high-impedance ground faults
symmetrical components method
current branching coefficient
phase current power frequency variation ratio
