一起500kV高压电抗器套管内部环流过热缺陷分析

Analysis of A Circulating Current Overheating Defect in 500kV High-voltage Reactor Bushing

本文通过对一台500kV高抗进行例行试验和油色谱检测,发现B、C相高压套管总烃超标,疑似存在低温过热缺陷,通过高压介损、局放、FDS等诊断性试验和解体分析,确定了过热点。过热原因为结构设计不当,导致屏蔽结构出现感应环流,通过理论计算和实测,评估了环流大小,并对过热铜铝界面电解腐蚀现象进行了探讨。本文的发现,为同类运维、缺陷诊断和结构优化提供了新的见解。

Through routine test and oil chromatographic detection of a 500kV high voltage reactor,it is found that the total hydrocarbon of phase B and C high voltage bushings exceeds the standard and is suspected to have low-temperature overheating defects.Through diagnostic tests and disassembly analysis such as high-voltage dielectric loss,partial discharge and FDS,the hot spots are determined.The reason of overheating is that the structure design is improper,which leads to the induced circulation in the shielding structure.Through theoretical calculation and actual measurement,the circulation is evaluated,and the phenomenon of electrolytic corrosion at the copper aluminum interface of hot spots is discussed.The findings of this paper provide new insights for similar operation and maintenance,defect diagnosis and structural optimization.