摘要
通过分析变压器传统纵差保护在反映接地故障时灵敏度上的不足,论述了装设零序差动保护的必要性。在分析了传统零序差动保护各种制动电流的选取方式后,对两卷变压器和自耦变压器的零序差动保护提出了一种通用的制动电流选取方式。同时,还针对传统差动保护的动作特性单一的缺点,提出了变特性的差动保护设计新思路,并在此基础上给出了零序差动保护的设计新方案。最后,还根据现场实际情况给出了一种效验中性点零序CT极性的方法,为零序差动保护在现场的正确应用提供了有力的支持。
It is necessary to install zero-sequence differential protection because conventional differential protection is not sensitive enough to grounded fault. Based un the analysis of selection modes of constrained current for conventional zero-sequence differential protection, this paper presents a general constrained current selection mode for double-winding transformer and self-coupling transformer. Instead of single operating characteristic, this paper puts forward multi-chartacteristic differential protection and design scheme of zerosequence differential protection. A method for neutral polarity testing of zero-sequence TA is proposed according to the real conditions on worksite, which is helpful for the correct application of zero-sequence differential protection on spot.
出处
《继电器》
CSCD
北大核心
2005年第15期13-17,共5页
Relay
关键词
变压器
励磁涌流
零序差动保护
transformer
excitation current
zero-sequence differential protection
