摘要
国内某电厂的定子接地保护拒动起因于不正确的PT接线。文章分析了当PT二次侧采用B相接地时,PT与电压变换器的中性点连接方式对保护动作行为的影响。结论表明:当二者中性点断开时,保护装置的测量结果不能正确反映一次系统的运行状态,PT断线判据可能误动;而当中性点直接相连时,保护装置能够正确动作。
Failure to operation of stator winding grounding fault oceurred in a domestic power plant resulted from false PT secondary connection, The paper analyzes the influence of connection mode between neutral points of PT and voltage transducers on actions of relay when phase B is grounded in PT secondary side. The conclusions show that measurements of relay protection could not reflect operation states of primary System and criterion of PT secondary broken connection may result in false operation when the connection between neutral points of PT and voltage transducers is broken. Protection relays can correctly operate when neutral points directly connected.
出处
《继电器》
CSCD
北大核心
2006年第5期17-20,共4页
Relay
关键词
定子接地
PT断线
B相接地
stator winding grounding
PT secondary broken connection
phase B earthing
