硅氧化焼注入后水树老化交联聚乙烯电缆电气特性和微观结构（英文）  

Electrical Properties and Micro-structures of Water-tree Aged XLPE Cables After Siloxane Fluid Injection

作　　者：周凯[1] 熊庆 赵威 温伟杰 陶文彪[1] 

机构地区：[1]School of Electrical Engineering and Information, Sichuan University

出　　处：《高电压技术》2015年第8期2732-2740,共9页High Voltage Engineering

基　　金：Project supported by National Natural Science Foundation of China(51477106)

摘　　要：To evaluate the effect of using siloxane liquid to rejuvenate water tree defects in cross-linked polyethylene(XLPE)cables,we investigated the electrical properties and micro-structures of water-tree aged XLPE cables after siloxane liquid injection treatment.The water-tree aged samples were prepared by performing accelerated aging experiment using water-needle electrodes,and the siloxane liquid is injected into the aged cable through a pressurized injection system.Dielectric loss factors of the samples before and after the rejuvenation were compared.The water trees and the internal filler were observed using scanning electron microscope(SEM).Electrical properties of the reactants are measured.Electric field simulation is conducted to verify the rejuvenation effect by finite element method.The results show that the siloxane liquid diffused into the insulation layer in a short time and reacted with water in the water trees.The electrical properties of the formed organic filler are in accord with that of XLPE.Therefore,the action between siloxane and water can inhibit the growth of water trees and reduce electric field distortion of the water tree areas.As a result,insulation performance of the cable is enhanced.A 70 m long cable was aged and rejuvenated in laboratory and an on-site rejuvenation experiment was conducted,and in both cases the dielectric loss factor and leakage current halved after rejuvenation.In order to investigate the inhibition effect and its mechanism of prior rejuvenation for water trees in XLPE cables in service, the prior rejuvenation cable samples were prepared by injecting siloxane liquid into the core of new cables with a pressure. New cable samples and the prior rejuvenation cable samples were subjected to accelerated aging experiment using the water-needle electrical method. By optical microscope, the water trees in the cable samples were observed and the lengths of water trees were measured at different aging times. Meanwhile, molecular structures and mi- crostructure of the water tree areas in XLPE cable samples were observed and analyzed by infrared spectrometer （IR）, scanning electron microscope （SEM） and energy disperse spectroscopy （EDS）. The results indicate that the average length of water trees in the untreated cable samples is 0.4 times longer than that in the prior rejuvenating cable samples after aged 4 weeks. By SEM and EDS, few micro pores but a large amount of white particles comprised of silicon were ob- served in the water tree area of the prior rejuvenation cable samples. It is proposed that the rejuvenation liquid was able to diffuse into the insulation; it reacted with water molecule during the accelerated aging experiment and generated organic particles that filled micro pores in water tree. Therefore, it can inhibit water tree growth in XLPE cables.

关 键 词：交联聚乙烯电缆 修复液 预修复 水树 抑制作用 微观形貌 

分 类 号：TM24[一般工业技术—材料科学与工程]