750kVGIS隔离开关用绝缘拉杆炸裂原因分析

盆式绝缘子、绝缘拉杆、支柱绝缘子等绝缘件作为GIS设备内部重要的绝缘、传动部件,故障率仅次于异物放电。通过绝缘拉杆运动特性分析、X射线成像检测、异物分析、微观分析、电场仿真分析等方法,对一起750 kV GIS 设备隔离开关交接试验过程击穿炸裂进行分析。针对分析结果给出了隔离开关的故障原因为连接机构侧的绝缘管粘接面加工操作不当造成了绝缘管层间疏松,导致粘接面存在气隙缺陷,缺陷逐渐延伸扩展,最终诱发绝缘拉杆层间连续放电通道。

Explosion analysis of the insulation pulling lever for 750 kV GIS isolating switch

As important insulation and transmission parts of GIS equipment, basin insulator, insulation pulling lever, post insulator and other insulation parts have a failure rate second only to foreign matter discharge. Through the analysis of the movement characteristics of the insulating rod, X-ray imaging detection, foreign matter analysis, micro analysis, electric field simulation analysis and other methods, the breakdown and explosion of a 750 kV GIS equipment isolating switch during the handover test was analyzed. According to the analysis results, the fault reason was that the improper processing of the bonding surface of the insulated pipe on the connection mechanism side caused the interlayer looseness of the insulating pipe, resulting in the air gap defect on the bonding surface, which gradually extended and expanded, and finally induced the continuous discharge channel between the insulation rod layers.