电晕放电加速硅脂劣化对硅橡胶绝缘表面性能的影响  

Effect of Corona-discharge-accelerated Deterioration of Silicone Grease on the Surface Properties of Silicone Rubber Insulation

作　　者：王霞[1] 王华楠 陈飞鹏 吴锴[1] 崔江静 仇炜 WANG Xia;WANG Huanan;CHEN Feipeng;WU Kai;CUI Jiangjing;QIU Wei(State Key Laboratory of Electrical Insulation and Power Equipment,Xi’an Jiaotong University,Xi’an 710049,China;Guangzhou Power Supply Bureau of Guangdong Power Grid Co.,Ltd.,Guangzhou 510410,China;Zhuhai Power Supply Bureau of Guangdong Power Grid Co.,Ltd.,Zhuhai 519000,China)

机构地区：[1]西安交通大学电力设备电气绝缘国家重点实验室,西安710049 [2]广东电网有限责任公司广州供电局,广州510410 [3]广东电网有限责任公司珠海供电局,珠海519000

出　　处：《高电压技术》2020年第11期3977-3985,共9页High Voltage Engineering

基　　金：广东电网有限责任公司珠海供电局科技项目(GDKJXM20161743)。

摘　　要：硅脂广泛用于电缆附件安装过程的表面润滑和密封。但电缆附件绝缘在长期运行过程中受到硅脂的溶胀作用,且电缆与附件绝缘界面易发生沿面电晕放电乃至击穿故障。而不同硅脂在电晕老化作用下对界面电气性能和硅橡胶机械性能的影响未见报道。为此选择了6种不同涂覆硅脂,研究涂覆不同硅脂的硅橡胶在电晕老化后表面粗糙度、分子基团与交联结构、复合界面击穿电压和硅橡胶本体机械性能的变化。结果发现:电晕老化破坏了硅脂和硅橡胶的表面形态和硅橡胶的交联结构,导致界面绝缘强度和硅橡胶机械性能下降严重;硅脂和硅橡胶表面出现的裂纹孔洞以及极性分子等使涂覆硅脂的试样表面粗糙度增加;而XLPE/SR复合试样界面击穿电压与硅橡胶试样表面粗糙度值呈负相关:表面粗糙度越大的试样其复合界面击穿电压越低。另外,本文提供了一种简单的硅脂性能测试思路:通过对涂覆不同硅脂的硅橡胶试样在电晕老化后的界面电气性能和机械性能等测试,可以筛选出性能稳定的硅脂。Silicone grease is widely used for surface lubrication and sealing in cable accessories installation. However, the insulation of cable accessories is affected by the swelling of silicone grease for a long time, where the surface discharge even interface breakdown easily occurs. So far the literature on the influence of different silicone greases with corona aging on interfacial electrical property and mechanical properties of silicone rubber is not available. Therefore, six kinds of silicone greases were selected for studying the changes of surface roughness, molecular groups and cross-linking structure, interfacial breakdown voltage and mechanical properties of silicone rubber coated with different silicone greases under corona aging. The results show that corona aging can destroy the surface morphology of silicone grease, silicone rubber, and its crosslinked structure, resulting in serious decrease in interfacial dielectric strength and mechanical properties of silicone rubber. Additionally, the cracks, holes and polar molecules on the surface of silicone grease and silicone rubber will increase the surface roughness of the coated sample, with which the interfacial breakdown voltage of XLPE/SR composite sample is negatively correlated, namely, the sample coated with a higher surface roughness has a lower interfacial breakdown voltage. Furthermore, a simple performance test of silicone grease can be provided as follows: some better silicon grease can be selected by performing the experiments for electrical and mechanical properties of silicone rubber coated with different silicone grease under corona aging.

关 键 词：硅橡胶 硅脂 溶胀 电晕放电 界面 

分 类 号：TM24[一般工业技术—材料科学与工程]