含硅氧结构聚酰亚胺薄膜的高频沿面放电特性  

High Frequency Surface Discharge Characteristics of Polyimide Films With Silicon Oxygen Structure

作　　者：丁梓桉 邢照亮 黄旭炜 李庆民 赵维佳 王忠东[3] DING Zi'an;XING Zhaoliang;HUANG Xuwei;LI Qingmin;ZHAO Weijia;WANG Zhongdong(State Key Lab of Alternate Electrical Power System with Renewable Energy Sources(North China Eletric Power University),Changping District,Beijing 102206,China;State Key Laboratory of Advanced Power Transmission Technology(Global Energy Interconnection Research Institute Co.,Ltd.),Changping District,Bejing 102209,China;School of Electrical and Electronic Engineering,University of Manchester,Manchester MI39PL,UK)

机构地区：[1]新能源电力系统国家重点实验室(华北电力大学),北京市昌平区102206 [2]先进输电技术国家重点实验室(全球能源互联网研究院有限公司),北京市昌平区102209 [3]曼彻斯特大学电气与电子工程学院,英国曼彻斯特M139PL

出　　处：《中国电机工程学报》2021年第1期211-221,共11页Proceedings of the CSEE

基　　金：国家自然科学基金项目(51737005);先进输电技术国家重点实验室开放基金项目资助(GEIRI-SKL-2019-002)。

摘　　要：用于高频电力变压器匝间绝缘的聚酰亚胺,因沿面放电而易发生绝缘失效,利用硅氧结构进行改性是有效的解决方法。该文研究高频电应力下含硅氧结构聚酰亚胺薄膜的沿面放电特性,通过向聚酰亚胺中引入5%等效摩尔含量的纳米SiO2粒子(SiO2-PI)和二硅氧烷GAPD(GAPD-PI),与纯聚酰亚胺(PI)一起进行沿面绝缘强度和全寿命沿面放电特性测试,并结合电阻率、紫外-可见光谱、SEM等测试技术开展比较分析。结果表明:在针-板电极的高频沿面放电中,电晕易向前发展,闪络破坏性更大,正半周比负半周放电更为剧烈,极性反转处放电强度大。放电幅值先出现波动而后到达峰值,单位时间内放电次数持续上升,密集放电比重逐渐增加。含硅氧结构改性聚酰亚胺的沿面绝缘强度均有所提升,其中GAPD-PI更好。SiO2-PI前期的放电幅值与次数与PI相近,密集放电多于PI,但PI发展迅速,后期放电的剧烈程度超过SiO2-PI。进一步研究给出材料改性对高频沿面放电特性的影响机制:放电前期,电阻率影响较大,大电阻率会抑制沿面放电发展;放电中后期,陷阱密度、深度的增加导致放电剧烈程度增加,此时光能影响较大,吸收光能一方面使材料电荷转移络合作用增强,另一方面减轻了光能对放电的促进作用。同时,材料化学结构也对沿面放电特性产生较大影响。Polyimide used in turn-to-turn insulation of high frequency power transformer is prone to insulation failure due to surface discharge. The modification with silicon oxygen structure is an effective solution. Therefore, this paper focused on the study of the surface discharge characteristics of polyimide films with silicon oxygen structure under high frequency alternating current stress, introduced 5% equivalent mole content of nano SiO2 particles(SiO2-PI) and disiloxane GAPD(GAPD-PI) into polyimide. The surface insulation strength and surface discharge characteristics were tested with pure polyimide(PI). A comparative analysis was carried out by combining resistivity, UV-vis spectroscopy, SEM and other testing techniques. The results show that in the high frequency surface discharge with pin-plate electrodes, the corona tends to develop forward easily, and the flashover is more destructive. Discharge in the positive half cycle discharge is more intense than the negative half cycle, and the discharge around the polarity reversal also has the high intensity. The discharge amplitude fluctuates in the first place and then reaches the peak value. The number of discharge per unit time continues to rise. The proportion of cluster discharge gradually increases. The surface insulation strength of polyimide with silicon oxygen structure are improved, and GAPD-PI is better. The amplitude and times of discharge in the early stage of SiO2-PI are similar to those of PI, even the cluster discharge is more than that of PI. But PI develops rapidly, and the intensity of discharge in the later stage is more than SiO2-PI. It is revealed that the influence mechanism of the modification on the high frequency surface discharge is as follows: in the early stage of the discharge, the resistivity renders a sensible influence. Large resistivity will inhibit the development of surface discharge;in the interim or later phase of the discharge, the increase of trap density and depth leads to the increase of discharge intensity, and the light e

关 键 词：硅氧结构 聚酰亚胺 高频应力 沿面放电特性 

分 类 号：TM211[一般工业技术—材料科学与工程] TM855[电气工程—电工理论与新技术]