高低温循环老化协同硅脂溶胀对XLPE/SiR复合介质界面电荷特性的影响  

Effect of High-and Low-temperature Cycle Aging Combined with Slicone Grease Swelling on the Interface Charge Characteristics of XLPE/SiR

作　　者：王霞[1] 陈润邦 陈宇奇 吴超[1] 吴锴[1] WANG Xia;CHEN Runbang;CHEN Yuqi;WU Chao;WU Kai(State Key Laboratory of Electrical Insulation and Power Equipment,Xi’an Jiaotong University,Xi’an 710049,China)

机构地区：[1]西安交通大学电工材料电气绝缘全国重点实验室,西安710049

出　　处：《高电压技术》2024年第11期5067-5077,共11页High Voltage Engineering

基　　金：国家自然科学基金(52077171)。

摘　　要：机车用电缆附件在运行过程中,不仅处于温度不断变换的环境,而且长期运行会受到界面涂敷硅脂的溶胀的作用,这些因素都会对其安全可靠运行造成一定威胁,但是相关的研究未见报道。为此根据实际机车运行的极端环境温度(−40~90℃),选用性能优良的硅脂,研究了高低温循环老化协同硅脂的溶胀作用对交联聚乙烯和硅橡胶的分子结构、电学性能和复合界面的空间电荷分布的影响。结果表明:交联聚乙烯在高低温循环老化以及涂覆硅脂后内部结构被破坏,试样的电导率和介电常数在老化后有一定程度增大;硅橡胶在仅受高低温循环老化条件下,老化促进了分子链的再交联作用使得试样电导率下降,而老化同时使极性基团密度的增大,导致试样的介电常数有所增大;而涂敷硅脂的硅橡胶在高低温循环老化后,由于硅脂的溶胀作用分子结构被破坏,使得材料的电导率和介电常数增幅明显。交联聚乙烯和硅橡胶的极性和电导率决定了交联聚乙烯/硅橡胶(crosslinked polyeth-ylene/silicon rubber,XLPE/SiR)夹层界面电荷的性质,涂覆硅脂的硅橡胶老化后的电导率高、极性强、界面电荷积累显著,并且由于硅脂的溶胀作用硅橡胶内部电荷累积现象明显。During the operation of cable accessories for locomotives,they are not only in an environment where the temperature is constantly changing,but also affected by the swelling of the interface coated with silicone grease for long-term operation.These factors will pose a certain threat to their safe and reliable operation,however,the related re-search has not been found in the literature.In this paper,according to the extreme ambient temperature(-40~90℃)of the actual locomotive operation,the silicone grease with excellent performance was selected.The effects of high-and low-temperature cycle aging combined with the swelling effect of silicone grease on the molecular structure,electrical properties and space charge distribution of cross-linked polyethylene and silicone rubber were studied.The results show that the internal structure of crosslinked polyethylene is destroyed after high-and low-temperature cycle aging and coat-ing silicone grease,and the conductivity and dielectric constant of the sample increase to a certain extent after aging.Under the condition of only high and low-temperature cycle aging,aging promotes the re-crosslinking of molecular chains,which reduces the conductivity of the sample,while aging also increases the density of polar groups,resulting in an increase in the dielectric constant of the sample.After the silicone rubber coated with silicone grease is aged at high-and low-temperatures,the molecular structure is destroyed due to the swelling effect of silicone grease,which enables the conductivity and dielectric constant of the material to increase significantly.The polarity and conductivity of cross-linked polyethylene and silicone rubber determine the properties of the interfacial charge of the interlayer of crosslinked poly-ethylene/silicon rubber(XLPE/SiR).The silicone rubber coated with silicone grease has high conductivity,strong polarity and significant interfacial charge accumulation after aging,and the internal charge accumulation of silicone rubber is ob-vious due to the swelling

关 键 词：电缆附件 高低温循环老化 硅脂 溶胀 空间电荷 

分 类 号：TM247[一般工业技术—材料科学与工程]