摘要
500 kV变电站电压互感器二次回路一点接地采用传统接线方式,即各电压等级电压二次回路中性点零相N600集中在500 kV继保室一点接地,该接线方式已经不能适应于分散式500 kV变电站;论述了不能适应应用产生的原因及在发生故障时,可能造成接地零序保护正方向拒动而向反方向误动的事故。提出将分散式500 kV变电站中各电压等级的各保护设备相对独立,只与本侧电压有关,即将220 kV和500 kV电压回路的N600连线解开,在各继保小室设立各电压回路的N600接地点的改进方案。所提出的接线方法在某500 kV变电站应用后,运行效果良好。
In 500kV substations,the one-point grounding of PT（Potential Transformer） secondary circuit is wired in traditional way,i.e.the neutral zero phase N600s of secondary circuit at different voltage levels are concentrated in 500 kV relay protection room for one-point grounding,which is no longer suitable for the distributed 500 kV substations.The reasons are analyzed.Furthermore,it may result in positive directional operation rejection and reverse directional misoperation of zero sequence pilot protection.Improved scheme is proposed,which opens the N600 tie-line between 220 kV and 500 kV,and configures the N600 grounding point for each voltage level in the relevant relay protection room,making the protection device of different voltage levels relatively independent of each other.Application in a 500 kV substation shows its better operating effect.
出处
《电力自动化设备》
EI
CSCD
北大核心
2010年第8期142-143,147,共3页
Electric Power Automation Equipment
关键词
变电站
二次回路
一点接地
改进方案
电压互感器
substation
secondary circuit
one-point grounding
improvement scheme
potential transformer
