220 kV变压器中性点发热原因分析及处理  

Cause Analysis of Neutral Point Heat of 220 kV Transformer and Its Treatment

作　　者：陈鑫 姜华[1] 邢钢 张祥[1] CHEN Xin;JIANG Hua;XING Gang;ZHANG Xiang(Ulanqab Electric Power Bureau,Ulanqab 012000,China)

机构地区：[1]乌兰察布电业局,内蒙古乌兰察布012000

出　　处：《内蒙古电力技术》2021年第6期98-100,共3页Inner Mongolia Electric Power

摘　　要：针对乌兰察布电业局某220 kV无人值守变电站4号主变压器中性线接地端温度异常升高的现象,分析了中性点电压偏移、中性点直流电阻以及主变压器零序电流二次回路对中性线发热的影响,判定发热原因为:中性点外置零序电流互感器串入中性线回路,导致中性线接地处直流电阻过大,当变电站负荷不平衡时,零序电流增大,从而引起发热。从设计、验收、运维方面提出了防范措施,为220 kV变电站类似问题处理提供借鉴。Aiming at the abnormal temperature rise of neutral line grounding end of No.4 main transformer in a 220 kV unattended substation of Wulanqab Electric Power Bureau, the influences of neutral point voltage offset, neutral point DC resistance and primary transformer zero-sequence current secondary circuit on neutral line heating are analyzed. The abnormal heating are caused by the neutral point external zero-sequence current transformer connected to the neutral line loop, resulting in excessive DC resistance at the neutral line junction. When the substation load is unbalanced, the zero-sequence current increases, resulting in the abnormal heating. The preventive measures are put forward from the aspects of design, acceptance, operation and maintenance, which can provide reference for the treatment of similar problems in 220 kV substation.

关 键 词：变压器 中性点 接地端发热 零序电流 直流电阻 

分 类 号：TM41[电气工程—电器]