电测与仪表Issue(23)：120-122,128,4.
110 kV 线路零序电流保护误动原因分析及对策
Cause Analysis on Zero Sequence Current Protection Maloperation of the 110kV Line and Its Countermeasures
摘要
Abstract
In Xuzhou power grid, a single-phase outlet grounding fault happened on the 110kV line of a 220kV sub-station, which led to zero sequence current protection maloperation of several 110kV lines.The zero sequence volt-age, which appeared when the single-phase grounding fault happened,resulted in the neutral gap’ s breakdown of the 110kV transformers which were connected to the non-fault lines.Consequently, the zero sequence short circuit cur-rent flowing in the opposite direction through the non-fault lines was responsible for the zero sequence current protec-tion maloperation.This paper put forward two countermeasures:one was to add a directional element to the zero se-quence current I, II protection of the 110kV line, and the other was only to use the last segment protection of the zero sequence current.The two countermeasures have been applied to Xuzhou power grid and good operation results have been achieved.关键词
线路保护/零序电流保护/误动/变压器/中性点间隙/方向元件Key words
line protection/zero sequence current protection/maloperation/transformer/neutral gap/directional el-ement分类
信息技术与安全科学引用本文复制引用
程真何,刘桂林..110 kV 线路零序电流保护误动原因分析及对策[J].电测与仪表,2014,(23):120-122,128,4.
