摘要
500kV六氟化硫(SF6)电流互感器内部故障时其端部高压外壳通过绝缘支撑件或均压电容屏或支撑玻璃钢筒对地放电,而其二次电流随着电流互感器一次接线方式的不同而不同,从而影响到保护的动作。为此,探讨了母线侧开关单元电流互感器故障时,一次侧在并联接线方式和串联接线方式下线路保护和母线保护的动作情况及需要注意的问题。即当电流互感器发生外壳接地故障时,若为并联接线方式,则线路保护可靠动作,母线保护可靠不动作;若为串联接线方式时,则线路保护和母线保护都有可能不动作。
During an internal fault of 500kV sulphur hexafluoride（SF6） current transformer（CT）,its top shell with high voltage discharges to earth through insulator support,capacitive screen or supportive glass fiber reinforced plastic column.The secondary currents of CT are different because of the different primary connections,and the operation of relay protection is affected.Therefore,the operation of line protection and bus protection under parallel connection and series connection on primary side during switch unit CT fault on bus side is discussed with matters needing attention indicated.During CT shell grounding fault,line protection operates reliably and bus protection doesn＇t operate under parallel connection;both line protection and bus protection may not operate under series connection.
出处
《广东电力》
2010年第4期71-74,共4页
Guangdong Electric Power
