摘要
介绍了110kV及以下微机线路保护合闸回路的接线,分析了无人值班变电站断路器在合闸过程中出现的由于辅助开关触点QF不能断弧使得合闸线圈LC或合闸保持继电器KTC线圈长期励磁、最终烧毁的原因,以及防跃回路启动后也有可能造成KTC线圈、KTLU线圈烧毁。提出如果将合闸保持继电器改为直流接触器,并将动合触点KTC1由瞬时动作改为瞬时动作、延时返回,保证在正常情况下先由断路器辅助开关触点QF断弧,若QF不能断开再由KTC1断弧,解除合闸自保持回路,就可以避免上述问题的发生。
The cl os e circuit of110kV microprocessor-based line protection is introduced.The bu rnout of closing coil LC or closing hold relay KTC coil during CB close operati on in unmanned substa-tion is analyzed,which is caused by the long-time exci tation as CB auxiliary contactor QF fails to open.If the leap-prevention circu it has started,it may also result in the burnout of KTC coil and KTL U coil.The countermeasure is suggested that the closing hold relay be changed into DC con-tactors and the operating mode of contactor KTC 1 be changed into“instantaneous operation and de-layed return”.Under norma l condition CB auxiliary contactor QF open first,and if QF fails,KTC 1 will open and th e closing hold circuit is thus cancelled.
出处
《电力自动化设备》
EI
CSCD
北大核心
2003年第7期61-63,共3页
Electric Power Automation Equipment
关键词
微机线路保护
合闸回路
防跃回路
micro processor-based line protection
close circuit
leap-prevention circuit
