Effects of Gaseous Defects on Glycerin-impregnated Multi-layer Film Insulation under Impulse of 160-nanosecond Wave-front
Effects of Gaseous Defects on Glycerin-impregnated Multi-layer Film Insulation under Impulse of 160-nanosecond Wave-front
复制标题
DOI：
10.1109/tdei.2014.004584
复制
发表时间：
2015-02-01
影响因子：
3.1
通讯作者：
Zheng, Xiaoquan
中科院分区：
文献类型：
--
作者：
Zeng, Chuang;Zheng, Xiaoquan
实验研究了在160 ns波前高压脉冲下，膜层间存在单个可见微小气体缺陷（气体夹杂缺陷）的高纯甘油浸渍多层聚丙烯（PP）薄膜绝缘的击穿行为。实验结果表明，在100%绕组覆盖率下，10层PP薄膜的绝缘样品在275 kV/mm电场下经过20次间隔数min的脉冲后仍保持完好，击穿场强从单层薄膜的500 kV/mm左右开始迅速线性下降，这与PP薄膜的本征击穿场强非常接近，至约330 kV/mm，用于4个膜层。随着薄膜层数（n）从4增加到10，击穿场强的下降趋势变得平缓，然后几乎保持不变，表明n的-0.05次方衰减规律是平坦的。当覆盖因子为50%~ 90%时，平均击穿场强为254 kV/mm，当n为5 ~ 8时，平均击穿场强的1 σ偏差为51 kV/mm，随着覆盖因子的减小，平均击穿场强略有下降，约为10%。对于约30个样品，在所有情况下的最低击穿场为173 kV/mm。实验结果表明，在15 kV/cm电场下，如果可见的微小气体缺陷不聚集成膜层间的长通道，则沿膜层表面不会发生沿着闪络，否则沿膜-甘油界面沿着闪络是不可避免的。
The breakdown behavior of high-purity-glycerin impregnated multi-layer polypropylene (PP) film insulation, with the existence of individually distributed visible tiny gaseous defects (defects due to gaseous inclusions) between the film layers, was investigated experimentally under high voltage impulse of 160-ns wave-front. The experimental results show that, for 100% winding coverage factor, the sample insulation of 10-layer PP film survived after 20 impulses of interval of several minutes at an electric field of 275 kV/mm. The breakdown field tends to decrease fast and linearly from about 500 kV/mm for 1-layer film, which is very close to the intrinsic breakdown field of the PP film, to about 330 kV/mm for 4 film layers. This tendency of falling of breakdown field becomes mild and then nearly staying as the number of film layers (n) increases from 4 to 10, indicating a flat decay law of n to the (-0.05-th) power. Furthermore, for 50%-90% covering factors, the average breakdown field is 254 kV/mm with 1-sigma deviation of 51 kV/mm when n ranges from 5 to 8, slightly decaying versus the reduction of covering factor by about 10%. The lowest breakdown field is 173 kV/mm in all cases for about 30 samples. The experimental data demonstrate that if visible tiny gaseous defects do not gather together into a long channel between film layers, no flashover will occur along film layer surface at a field of 15 kV/cm, otherwise flashover is inevitably initiated along the film-glycerin interface.