风电场35kV集电线路零序电流保护拒动分析  

Analysis on a Zero Sequence Protection Failure of 35kV Collecting Circuit in a Wind Farm

作　　者：李占龙 LI Zhanlong(China Three Gorges New Energy(Group)Co.,Ltd.,Zhangjiakou 075000)

机构地区：[1]中国三峡新能源(集团)股份有限公司,河北张家口075000

出　　处：《电力安全技术》2022年第8期29-32,共4页Electric Safety Technology

摘　　要：针对一起220 kV风电场中35 kV某集电线路开关柜出线电缆外接零序电流互感器金属护层接地线接地位置错误导致线路零序电流保护拒动,接地变和主变低压侧越级跳闸、母线PT保险烧毁事故进行分析,认为该35 kV外接零序电流互感器在小电阻接地系统中可以准确地测量线路发生单相接地时的零序电流,但开关柜线路出线电缆金属护层接地线穿过零序电流互感器的方式对测得的零序电流大小有很大的影响,并据此提出了防范措施。Analyses are carried out on an accident of line zero sequence protection failure,the skip tripping at the low-voltage side of grounding transformer and main transformer and the bus PT burnout caused by the wrong grounding position of shielding wire of zero sequence current transformer connected to the incoming cable of 35 kV collecting line switch cabinet in 220 kV wind farm.It is concluded that the 35 kV external zero sequence current transformer can accurately measure the zero sequence current when the line is single-phase grounded in the small resistance grounding system,but the way that the incoming cable shield wire of the switchgear passes through the zero sequence current transformer has a great impact on the measured zero sequence current.The corresponding preventive measures are put forward.

关 键 词：风电场 电流互感器 零序电流 PT保险烧毁 

分 类 号：TM614[电气工程—电力系统及自动化]