变压器油纸绝缘介质在直流电场中的空间电荷输运特性  

Space Charge Transport Properties of Oil-paper Insulation Materials Under DC Field Used in Transformer

作　　者：廖瑞金[1] 李伟[1] 杨丽君[1] 郝建[1] 周天春[1] 周欣[1] 

机构地区：[1]重庆大学输配电装备及系统安全与新技术国家重点实验室,重庆400030

出　　处：《高电压技术》2011年第5期1057-1065,共9页High Voltage Engineering

基　　金：国家重点基础研究发展计划(973计划)(2009CB724505-1);国家创新研究群体基金(51021005);中央高校基本科研业务费资助项目(CDJXS11150004)~~

摘　　要：为得到换流变压器中使用的矿物油浸普通牛皮绝缘纸和油浸热稳定绝缘纸在直流电场中的空间电荷输运特性,对试样在3种不同等级外施直流电场作用下采用电声脉冲法(PEA)进行了空间电荷密度分布测量实验,分析了试样在加压时和去压后的空间电荷总量及其演变规律。实验发现:油浸普通牛皮绝缘纸的空间电荷注入起始阈值比油浸热稳定纸低,其体内易于注入电荷。加压时,油浸普通牛皮绝缘纸的空间电荷注入、输运和集聚现象比油浸热稳定绝缘纸试样更显著,且电荷注入量和注入速度均会随外施场强的升高而增大;去压后,油浸普通牛皮绝缘纸体内残留空间电荷量较油浸热稳定绝缘纸多,电荷消散所需时间较长。油浸普通牛皮绝缘纸介质体内陷阱是以相对油浸热稳定绝缘纸更高密度的浅陷阱分布为主。油纸绝缘介质材料差异对空间电荷输运特性的影响机制还有待深入研究和分析。In order to realize the space charge characteristics of common kraft paper and thermally-stabilized paper both impregnated by mineral oil under DC field,the pulsed electro-acoustic method was used to measure the space charge distribution of samples under 3 different level DC field.The changing of the total amount space charge in these two kinds of samples within the applied voltage on and removed was discussed.Results show that the space charge injection threshold voltage of the Kraft paper is lower than that of the thermally-stabilized paper,and charge injection is easier for the Kraft paper.When electric filed is applied,the charge injection,transport,and accumulation are more obvious in the Kraft paper than those of the thermally-stabilized paper,and the total amounts of injection space charge and injection velocity increase as the applied electric filed of both kinds of paper increases.After the applied electric filed is removed,the total amount of charge left in bulk for the Kraft paper is more than that of the thermally-stabilized paper,and the decay of charge in the Kraft paper is slower.Moreover,the charge left in the bulk for both kinds of paper is mainly trapped by the shallow traps in the materials,but the trap density in the Kraft paper is higher than that in the thermally-stabilized paper.

关 键 词：变压器 油纸绝缘 空间电荷 电声脉冲(PEA) 输运 陷阱 

分 类 号：TM401.1[电气工程—电器]