GIS隔离开关用绝缘拉杆的放电研究分析及防范措施

Analysis and Prevention Measures of Discharge Research of Insulated Pull Rod in GIS Disconnector

对一起GIS隔离开关用真空浸胶绝缘拉杆在入厂验收试验时击穿进行了分析。用Maxwell3D分析软件对绝缘拉杆结构进行了电场仿真计算,其结构设计合理。对击穿零件采用了X射线探伤、解剖、着色探伤等不同的检测方法,分析出拉杆击穿是因为绝缘拉杆内部存在气隙缺陷所致,并采用Maxwell3D分析软件比较了绝缘拉杆不同部位的气隙缺陷对电场分布的影响。计算结果表明:当气隙缺陷在接近绝缘拉杆高压侧时电场激增最为严重,存在更高的放电隐患。基于以上分析结果并根据绝缘拉杆生产的工艺特点,提出了生产工艺过程的重点关注点,以防止绝缘拉杆在真空浸胶过程中出现气隙或层间分离等缺陷。同时在绝缘拉杆检查过程中增加强光检测方法,有效地筛选材料缺陷,使零件出厂合格率得到保障。

The flashover fault of VPI epoxy insulated pull rod in GIS disconnector is analyzed on the acceptance test. Electric field distribution is computed by Maxwell 3D simulation, results prove model design is a reasonable structure. Based on the detection methods of X-ray flaw detection and dissection and staining examination, the flashover reason has been found is that the insulated pull rod has internal air gaps. And then the influence of air gap defects at different parts of the insulated pull rod on the electric field distribution is analyzed by using Maxwell 3D simulation. According to the results, air gap defects close to the high voltage part are the most dangerous for electric field explosion. They are more likely to cause flashover. Based on the research achievements and according the feature of pro duction process of insulated pull rod, the practical focus for the manufacturing process of insulated pull rod are proposed, to prevent that the insulated pull rod has internal bubbles or air gaps in the process of impregnate the adhesive composed of epoxy resin and liquid anhydride under vacuum pressure. At the same time, in the process of inspection of insulated pull rod, the strong light detection method is added to effectively screen the material defects, so the qualified rate of the parts can be guaranteed.