特高压直流干式套管用环氧及环氧/皱纹纸复合材料介电特性研究  

Dielectric Properties of Epoxy Resin and Epoxy/Crepe Paper Composites Used in the Ultra High Voltage Direct Current Dry-type Bushing

作　　者：宁鑫[1] 彭宗仁[1] 冯骅[1] 刘鹏[1] 

机构地区：[1]电力设备电气绝缘国家重点实验室(西安交通大学),陕西省西安市710049

出　　处：《中国电机工程学报》2015年第4期995-1001,共7页Proceedings of the CSEE

基　　金：国家自然科学基金项目(51207123);特高压工程技术(昆明;广州)国家工程实验室开放基金项目(NEL201409)~~

摘　　要：为研究引入皱纹纸对环氧材料介电特性的影响,通过介电谱及热刺激去极化电流(thermally stimulated depolarization current,TSDC)测量技术,对特高压直流干式套管用环氧及环氧/皱纹纸材料复介电常数、TSDC特性进行了测量分析。提出了基于相对介电常数一阶导数的改进差分进化优化算法,该方法能有效分析环氧材料内各介电弛豫过程。试验结果表明:皱纹纸的引入使环氧复合材料复介电常数实部、虚部均变大(高温中频区除外),其高温直流电导率也显著增大。与纯环氧相比,环氧/皱纹纸复合材料α(温度低于175℃时)、β、δ过程的弛豫时间均减小;δ过程弛豫强度减小、β过程弛豫强度显著增大;δ过程活化能减小,δ过程活化能增加;环氧/皱纹纸复合材料中陷阱深度较浅、但陷阱密度显著增加。以上结果,可为干式套管绝缘材料配方评估、工艺改进提供方法及理论指导。The dielectric properties of epoxy resin and epoxy/crepe paper composites which used in the ultra high voltage direct current（UHVDC） dry-type bushing were studied by the broadband dielectric spectrum and thermally stimulated depolarization current（TSDC） measurement. A modified differential evolution optimization method based on the derivative of the relative permittivity was proposed to resolve the dielectric relaxations in epoxy resin and its composites. Results show that the epoxy/crepe paper composites have larger relative permittivity and dielectric loss factor（except for in moderate frequency at high temperature）, and dc conductivity at the high temperatures as well. The relaxation time of α（〈175 ℃）, β, δ process decreases with the addition of crepe paper; the dielectric relaxation strength of δ process decreases, whereas it increases for δ process; activation energy of ？ process decreases, whereas it increases for δ process. Trap density increases with the trap depth decreasing in epoxy/crepe paper composites compared with pure epoxy resin. The results are beneficial for the assessment of insulation material and manufacturing process improvement of dry-type bushing.

关 键 词：直流干式套管 环氧 皱纹纸 差分进化 介电弛豫 陷阱 

分 类 号：TM85[电气工程—高电压与绝缘技术]