为了研究交联聚乙烯(XLPE)电缆中水树的生长机理，采用水针电极、高频高压的方法对XLPE薄片试样进行加速水树老化实验，通过显微镜观察经硅油加热处理前后的水树形态，构建有限元仿真模型，分析水树生长与电-机械应力的关系，并建立了水树生长的数学模型。结果表明：电-机械应力是导致水树生长的主要原因。在交变电场的作用下，环境中的水分在电缆绝缘中的杂质或缺陷处聚集，形成一系列充水微孔，并对其周围XLPE材料形成交变的Maxwell应力，导致XLPE分子链因应力疲劳而发生断裂，疲劳断裂的累积导致微孔体积增大、数量增多，这些微孔通过水树通道相连形成树枝状的水树形态。
To study the mechanism of water tree growth in the cross-linked polyethylene (XLPE) cables, the XLPE slice samples were conducted accelerated water tree ageing test by liquid needle electrode and high-frequency high-pressure method, and the morphology of water trees before and after heating in sili-cone oil were observed by microscope. The relationship between water tree growth and electrical-mechani-cal stress was studied by finite element simulation model, and the water tree growth mathematical model was set up. The results show that the electrical-mechanical stress is the main cause of water tree growth. The moisture in environment gather at the impurities or defects of cable insulation under the action of alternating electric field, then the voids with water are formed. The alternating Maxwell stress is formed surrounding the water filled voids in XLPE materials, which causes the fracture of XLPE molecular chain because of stress fatigue. The accumulation of fatigue fracture results in the increase of volume and number of micro voids. The micro voids are connected by water tree channels, and the morphology of water tree is formed.
参考文献
| [1] | 周远翔;聂琼;邢晓亮;王云杉;王宁华;梁曦东;关志成.频率对高密度聚乙烯电树老化特性的影响[J].高电压技术,2008(2):220-224. |
| [2] | Chen, X.;Xu, Y.;Cao, X.;Dodd, S.J.;Dissado, L.A..Effect of tree channel conductivity on electrical tree shape and breakdown in XLPE cable insulation samples[J].IEEE transactions on dielectrics and electrical insulation: A publication of the IEEE Dielectrics and Electrical Insulation Society,20113(3):847-860. |
| [3] | A. Najafi Pour;S.M. Shahrtash.A comprehensive circuit model for partial discharge activities in cable insulation due to electrical treeing[J].International journal of electrical power and energy systems,20131(1):646-655. |
| [4] | 党智敏;亢婕;屠德民.EAA改性XLPE中空间电荷和电树、水树的关系[J].中国电机工程学报,2001(7):5-8. |
| [5] | 周凯;陶文彪;赵威;杨滴;杨明亮.以分子取向理论理解交联聚乙烯中水树在不同温度下的生长特性[J].高电压技术,2014(12):3665-3673. |
| [6] | 豆朋;文习山;龚瑛.几种因素对水树生长影响的研究[J].绝缘材料,2005(1):33-36. |
| [7] | 金天雄;黄兴溢;江平开;仲含芳;金义天.热老化对交联聚乙烯电缆绝缘中水树的影响研究[J].绝缘材料,2007(5):45-48. |
| [8] | 陶文彪;周凯;沈智飞;张圣博;武拥建.XLPE电缆中水树区域干湿状态下的电场特性研究[J].绝缘材料,2015(2):53-55,67. |
| [9] | Steennis E.F.;Kreuger F.H..Water treeing in polyethylene cables[J].IEEE transactions on electrical insulation. (Institute of Electrical and Electronics Engineers. Electrical Insulation Group). New York.,19905(5):989-1028. |
| [10] | Ross R.;Smit J.J..Composition and growth of water trees in XLPE[J].IEEE transactions on electrical insulation. (Institute of Electrical and Electronics Engineers. Electrical Insulation Group). New York.,19923(3):519-531. |
| [11] | Wang, Z.;Marcolongo, P.;Lemberg, J.A.;Panganiban, B.;Evans, J.W.;Ritchie, R.O.;Wright, P.K..Mechanical fatigue as a mechanism of water tree propagation in TR-XLPE[J].IEEE transactions on dielectrics and electrical insulation: A publication of the IEEE Dielectrics and Electrical Insulation Society,20121(1):321-330. |
| [12] | Robert Ross.Inception and propagation mechanisms of water treeing[J].IEEE transactions on dielectrics and electrical insulation: A publication of the IEEE Dielectrics and Electrical Insulation Society,19985(5):660-680. |
| [13] | S. Hvidsten;E. Ildstad;J. Sletbak;H. Faremo.Understanding water treeing mechanisms in the development of diagnostic test methods[J].IEEE transactions on dielectrics and electrical insulation: A publication of the IEEE Dielectrics and Electrical Insulation Society,19985(5):754-760. |
| [14] | 金天雄;黄兴溢;江平开;刘飞;郑学哲.用有限元法分析水树尺寸对电场分布的影响[J].高电压技术,2008(3):489-491,564. |
| [15] | 周凯;陶霰韬;赵威;李旭涛;刘凡.在水树通道内生成纳米TiO2的电缆修复方法及其绝缘增强机制研究[J].中国电机工程学报,2013(7):202-210,前插26. |
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