绝缘纸热老化对油浸绝缘纸空间电荷生成及迁移特性的影响  

Influence of Insulation Paper's Thermal Aging on the Formation and Migration Behavior of Space Charge in Oil-Paper Insulation Dielectrics

作　　者：廖瑞金[1] 柳海滨[1] 周年荣 夏桓桓 林元棣[1] 郭沛[1] 

机构地区：[1]输配电装备及系统安全与新技术国家重点实验室(重庆大学),重庆400044 [2]云南电力试验研究院(集团)有限公司电力研究院,昆明650217

出　　处：《电工技术学报》2015年第22期206-214,共9页Transactions of China Electrotechnical Society

基　　金：国家自然科学基金资助项目(51277187)

摘　　要：油纸绝缘介质在高压直流电场的作用下容易在其内部积聚空间电荷,造成电场畸变进而引发材料绝缘性能的下降,为了深入探索油纸绝缘系统空间电荷的生成机理,研究区分绝缘纸老化和绝缘油老化对油纸绝缘介质空间电荷生成及迁移的影响具有重要意义。首先将纤维素绝缘纸在130℃下进行加速热老化,然后将不同老化状态绝缘纸浸渍新绝缘油,得到不同老化状态的油纸试品,最后运用电声脉冲(PEA)法研究油纸试品的空间电荷注入、迁移和消散特性,并分析单纯绝缘纸老化对油纸绝缘试品在加压和去压过程中的空间电荷总量变化规律的影响,以及对油纸试品表面陷阱能级密度分布的影响。结果表明:随着绝缘纸老化程度的加深,加压过程中阳极处的正电荷密度峰值以及试品内部负电荷密度峰值逐渐增大,去压后空间电荷衰减速率减小;绝缘纸老化越严重,试品内部积聚的空间电荷总量、试品的表面陷阱能级密度也越大。与绝缘油老化对油浸绝缘纸空间电荷特性的影响相比发现,绝缘油与绝缘纸的老化均会改变油纸绝缘介质空间电荷分布,增大空间电荷注入总量,从而对材料绝缘性能造成巨大影响。Space charge is easy to accumulate in oil-paper insulation system under high voltage DC field, which will cause the distortion of internal electric field, thus leading to the degradation of material insulation performance. Therefore, research on the influence of insulation paper aging on the space charge properties in oil-paper insulation dielectrics is of great significance. In this respect, the accelerated thermal aging experiment of insulation paper is conducted under 130~C and then these papers was impregnated with new insulation oil to get the oil-paper aged for different time. Then the injection, migration and dissipation characteristics in oil-paper insulation system were studied with pulsed electro-acoustic（PEA） method. The influence of insulation paper＇s thermal aging on the total amount of space charge under voltage on process and decay process, were investigated as well as on the surface trap energy density. The results show that the maximum positive charge density at the anodeand the maximum negative charge density within the samples during voltage on process increase while the decay rates of space charges decrease with the insulation paper aging degree.The more the deterioration of the insulation paper, the larger the total amount of space charge with samples and the surface trap energy density. By investigating the influence of oil aging on space charge properties in oil-paper insulation dielectrics, it turns out the thermal agings of insulation oil and paper both will affect the distribution of space charge in oil-paper insulation dielectrics and increase the total amount of space charge, thus causing a great influence on the insulation performance of materials.

关 键 词：绝缘纸 油纸绝缘 热老化 空间电荷 电荷总量 电声脉冲法 表面陷阱能级密度 

分 类 号：TM85[电气工程—高电压与绝缘技术]