低密度聚乙烯–蒙脱土纳米复合材料的电树枝生长特性  

Growth Properties of the Electrical Trees in LDPE-MMT Nano-composites

作　　者：章华中[1] 李剑[1] 梁勇[1] 杨丽君[1] 廖瑞金[1] 赵玉顺[1] 

机构地区：[1]输配电装备及系统安全与新技术国家重点实验室(重庆大学),重庆市沙坪坝区400044

出　　处：《中国电机工程学报》2010年第31期137-142,共6页Proceedings of the CSEE

基　　金：国家自然科学基金青年科学基金项目(50807054)~~

摘　　要：绝缘材料的电树枝生长特性分析是评估其绝缘性能的重要方法之一。采用熔融插层复合法制备了一种低密度聚乙烯–蒙脱土纳米复合材料,设计制作了纳米复合材料的电树枝生长试样及实验系统,在实验中观测了恒定电压下试样中电树枝生长过程及电树枝形态,测量了试样中电树枝的生长速度与扩散系数,分析了电树枝的局部放电统计特性。通过分析低密度聚乙烯–蒙脱土纳米复合材料的结晶行为,说明了纳米蒙脱土对该纳米复合材料中电树枝的抑制机制。实验与分析结果表明:纳米蒙脱土粒子有效提高了低密度聚乙烯的结晶度并减小了晶粒尺寸。同时,纳米蒙脱土粒子有利于降低纳米复合材料电树枝局部放电量与放电重复率,延缓了电树枝的引发与生长。Analysis on growth properties of electrical trees in insulation material is an important approach to evaluate its performances. This paper presents a type of low-density polyethylene （LDPE）-montmorillonite （MMT） nano-composite prepared by a melting intercalation process. A testing system and specimens of electrical trees growing in the nano-composite were designed and made. Growth process and morphology of electrical trees in these specimens were observed in the experiments under a constant voltage stress. Growth rates and expansion coefficients of the electrical trees in the specimens were measured and statistical characteristics of partial discharges （PDs） in electrical trees were analyzed. The me.chanism of electrical trees in the LDPE-MMT nano-composites restrained by MMT nano-particles was illustrated through analysis of crystallization behavior of the nano-composites. Experiments and analysis results showed that MMT nano-particles improve the crystallinity degrees and decrease the grain sizes of LDPE..Meanwhile, MMT nano-particles are helpful to reduce quantities and repetition rates of PDs in electrical trees of the nano-composite and to postpone inception and growth of the electrical trees.

关 键 词：低密度聚乙烯 蒙脱土:纳米复合材料 电树枝 局部放电 高电压绝缘技术 

分 类 号：TM85[电气工程—高电压与绝缘技术] TM215[一般工业技术—材料科学与工程]