摘要
热因素是影响高压电缆绝缘层交联聚乙烯绝缘微观形态的关键因素之一。选取1根运行7年与1根新电缆分别制备绝缘层交联聚乙烯片状试样,首先在105℃下进行180 d的热老化,然后在90~115℃对各老化试样进行恒温24 h的短时热处理,并完成交联度、差示扫描量热、高场强电导测试。结果表明:老化初期,热老化助于交联聚乙烯结晶,且热处理有利于熔融温度与结晶度升高,晶体尺寸分布变小,电导率减小;随着热处理温度升高,上述参数逐渐到达最优值,并随热处理温度升高而开始反向变化;随着老化程度加深,相同热处理温度后各参数提升作用减弱,表现为参数最优值对应的热处理温度降低且与未老化试样差异逐渐减小,老化180 d后各参数值均明显低于未老化试样。研究表明,经历一定热老化的交联聚乙烯在合理温度下短时热处理后,可有效改善内部结晶特征,提升热电性能。
The thermal factor is one of the key factors influencing the microstructure of the crosslinked polyethylene(XPLE)insulation layer in the high-voltage cable.This study selects a 7 year serviced cable and a new cable respectively to prepare for sheet XPLE samples.Firstly,it conducts heating aging tests for the samples for 180 days at 105℃and then short-term heating treatment for 20 h at constant temperature at 90~105℃.Afterwards,the study carries out the tests of crosslink degree,differential scanning calorimetry(DSC)and high field conductivity.The results reveal that in the early stage of aging,heating aging is contributed to crystallization of the XPLE and heating treatment is helpful to increase of fusing temperature and crystallinity,reduction of crystal size distribution and the electrical conductivity.With the increase of heating treatment temperature,the above parameters gradually reach to the optimal values and change reversely.As the aging degree deepens,the promotion effect of each parameter after the same heating treatment decreases,showing as reduction of the heating temperature corresponding to the optimal value of the parameter and gradual reduction of the difference with the non-aging sample.After 180 days of aging,all parameters are notably lower than those of the non-aging samples.The study indicates that short-term heating treatment at a reasonable temperature effectively enhances the internal crystallization characteristics and thermoelectric properties of XPLE after the heating aging.
作者
惠宝军
谢月
HUI Baojun;XIE Yue(National Engineering Research Center of UHV Technology and New Electrical Equipment,Guangzhou,Guangdong 510640,China;School of Automation,Guangdong Polytechnic Normal University,Guangzhou,Guangdong 510640,China)
出处
《广东电力》
北大核心
2024年第2期88-94,共7页
Guangdong Electric Power
基金
特高压电力技术与新型电工装备基础国家工程研究中心开放基金项目(NELUHV-2021-KF-11)。
关键词
高压电缆
交联聚乙烯
短时热处理
差示扫描量热
交联度
高场强电导
high-voltage cable
XLPE
short-term heat treatment
differential scanning calorimetry(DSC)
crosslink degree
high field conductivity
