温度梯度下SIR/EVA共混对电缆附件电树枝生长的抑制研究  

Suppression Method of SIR/EVA Blends on the Growth of Electrical Tree in Cable Accessories Under Temperature Gradient

作　　者：马婷婷 杜伯学 韩涛 张鑫鑫 刘超 郁杰 MA Tingting;DU Boxue;HAN Tao;ZHANG Xinxin;LIU Chao;YU Jie(Jiangsu Shemar Electric Co.,Ltd.,Nantong 226500,China;School of Electrical and Information Engineering,Tianjin University,Tianjin 300072,China)

机构地区：[1]江苏神马电力股份有限公司,南通226500 [2]天津大学电气自动化与信息工程学院,天津300072

出　　处：《高电压技术》2021年第12期4229-4235,共7页High Voltage Engineering

基　　金：国家自然科学基金(50707132)。

摘　　要：电缆附件硅橡胶(silicone rubber,SIR)绝缘长期处于由线芯发热产生的温度梯度环境中,与其内部复杂的电场分布共同加剧了绝缘电树枝劣化程度。电缆附件SIR在电、热耦合工况下,抑制电树枝引发和生长是避免电缆附件故障的有效手段。在交流耦合温差为±60℃的温度梯度环境下,研究了不同乙烯-醋酸乙烯(ethylene-vinyl acetate,EVA)共聚物含量的SIR/EVA共混材料对电树枝引发和生长的抑制作用,通过分析SIR/EVA共混材料的理化性能讨论了SIR/EVA共混材料对电树枝的抑制机理。试验结果表明:EVA的加入提高了电树枝起始电压,电树枝生长长度明显下降,对SIR电树枝的引发和生长具有较好的抑制作用;SIR/EVA共混材料断面交联均匀,EVA的添加引入了高键能的C=O双键,增强了SIR材料在一定温度范围内的拉伸强度,提高了SIR的机械性能。EVA与SIR发生物理交联使得复合材料的分子链断裂阈值上升,形成的交联结构阻碍了热电子打破SIR分子链和界面的输运,提高了SIR材料的电树枝起始电压和耐电树枝能力。The silicone rubber(SIR)insulation of cable accessories has been in a durative temperature gradient environment caused by the heating of the cable core,and the complex electric field distribution has aggravated the deterioration of electrical tree.The suppression of electrical tree inception and growth is an effective means to avoid the failures of the cable accessory under the electrical and thermal coupling conditions.In this paper,the suppression effect of ethylene-vinyl acetate copolymer(EVA)on electrical tree was researched under the conditions of the temperature gradient of±60℃and AC.The suppression effects of SIR/EVA blends on the inception voltages and growth of electrical tree were studied.According to the physical and chemical properties of SIR/EVA,the suppression mechanisms of electrical tree were discussed in SIR by employing EVA.The results show that the EVA can increase the electrical tree inception voltage,and the growth length of the electrical tree is significantly reduced,which has a better suppression effect on the electrical tree inception and growth in the SIR.The cross-linking of the SIR/EVA blends is uniform and the C=O double bonds with high bond energy enhances the tensile strength of SIR materials in a certain temperature range.The EVA improves the mechanical properties of SIR.The molecular chain break threshold is enhanced by the physical cross-linking between EVA and SIR.The thermal electrons transport is hindered by the crosslinked structure.Therefore,the electrical tree suppression ability is enhanced in SIR/EVA blends.

关 键 词：电缆附件 电树枝 SIR/EVA共混 抑制 电荷输运 

分 类 号：TM247[一般工业技术—材料科学与工程]