针板电极下局部放电对油浸绝缘纸板表面的影响

发布时间：2018-01-08 03:23

本文关键词：针板电极下局部放电对油浸绝缘纸板表面的影响　出处：《西安交通大学学报》2017年04期 　论文类型：期刊论文

【摘要】：针对油浸绝缘纸板在长期局部放电应力作用下的劣化问题,在针板电极下对油浸绝缘纸板进行了长期局部放电试验,对绝缘纸板的局部放电特性及表面形态的理化特性进行了测量和分析。其中,记录了长期局部放电发展过程中的局部放电相位分布(PRPD)图谱,对处于不同放电阶段的纸板进行了表面形貌、化学基团的观测,研究并给出了放电对纸板表面理化特性的影响机理。结果表明:油浸绝缘纸板的长期局部放电发展经历4个阶段,不同阶段放电由表面向内部发展,对纸板的损伤程度不同;局部放电会造成纸板中纤维的烧蚀及断裂,产生孔洞并不断扩大,形成气泡层;气泡层中不断发生的气体放电生成自由基,这些自由基会与纤维束表面的基团反应并改变其微观形态,促使放电向内不断发展;最终纸板内部堆积大量气泡,形成贯穿的气泡柱并导致纸板击穿。长期局放应力下绝缘纸板的微观结构破坏是导致纸板失效的重要原因,而PRPD图谱的变化是其在局部放电特性上的反映。
[Abstract]:Aiming at the deterioration of oil-impregnated insulating paperboard under the action of long-term partial discharge (PD) stress, a long-term partial discharge test was carried out on oil-impregnated insulating paperboard under needle plate electrode. The partial discharge (PD) characteristics and the physical and chemical properties of the surface morphology of insulating paperboard were measured and analyzed. Among them, the partial discharge phase distribution (PRPDD) pattern during the long term PD development was recorded. The surface morphology and chemical groups of paperboard at different discharge stages were observed. The influence mechanism of discharge on the physical and chemical properties of paperboard was studied. The results showed that the long-term partial discharge of oil-impregnated insulating paperboard went through four stages, and the discharge developed from surface to interior in different stages. The degree of damage to paperboard is different; Partial discharge will cause ablation and fracture of the fiber in paperboard, producing holes and expanding continuously, forming bubble layer; The gas discharge in the bubble layer produces free radicals, which react with the groups on the surface of the fiber bundle and change its microscopic morphology. Finally, a large number of bubbles accumulated inside the cardboard, forming through the bubble column and leading to board breakdown. The breakdown of microstructure of insulating paperboard under long-term partial discharge stress is an important reason for the failure of paperboard. The change of PRPD pattern is the reflection of partial discharge characteristics.
【作者单位】：西安交通大学电力设备电气绝缘国家重点实验室;国家电网湖南省电力公司电力科学研究院;
【基金】：国家自然科学基金资助项目(51577150)
【分类号】：TM855
【正文快照】： 油浸绝缘纸板在变压器中担负着主绝缘及机械固定不同电位导体的任务,在正常运行的电力设备中,其同时承受着强电场应力以及机械应力,并在这些应力的作用下不断劣化[1]。此外,由于正常运行的变压器内部温度较高,绝缘纸板中的纤维会不断裂解,进一步恶化设备内部绝缘状态,增加了设

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