摘要
油纸绝缘介质内部积聚的空间电荷与其绝缘性能密切相关,它可以导致介质内部电场分布的畸变,对局部电场起到削弱或加强的作用,若电场畸变严重,将引起绝缘材料的击穿和老化,直接影响绝缘系统的可靠性和安全性。水分和温度被认为是危害油纸绝缘介电强度和绝缘寿命的最主要因素,为了解它的特性,采用电声脉冲(PEA)法研究了油纸绝缘介质在温度和水分联合作用下空间电荷的注入、迁移、积聚和消散特性,进一步分析了水分和温度联合作用对油浸绝缘纸直流击穿和电荷积聚行为的影响。结果表明:油浸绝缘纸的水分含量和温度越高,其内部正负电荷的注入和迁移就越显著,而且油浸绝缘纸内部积聚的空间电荷在撤去外加场强后消散得也越快;对于未被外加场强击穿的油浸绝缘纸,其内部慢速运动电荷的量随着水分含量和温度的升高而减少;而对于被外加场强击穿的油浸绝缘纸,在击穿前其内部仅积聚极少量的负电荷。
Accumulation of space charge in oil-paper insulation system is closely related to oil-paper insulating properties,which can lead to distortion of the internal electric field distribution,and play a role in weakening or strengthening the nearby electric field.Severe electric field distortion will cause the breakdown and accelerating aging of insulating material,and will impair the reliability and security of the insulation system directly.Moisture and temperature are considered to be the most important factors which will decrease the oil-paper insulation dielectric strength and insulation life.We employed the pulsed electro-acoustic（PEA） method to study injection,migration,accumulation,and dissipation characteristics of space charge in oil-paper insulation system under the combination influence of temperature and moisture,and further analyzed the behaviors of space charge accumulation and sample breakdown in oil-immersed insulating paper under the combined effects of moisture and temperature.Results show that,the higher the moisture content and the temperature of the oil-paper sample are,the higher the mobility of the trapped charges in the sample,and the more obvious the positive charge injection and negative charge injection were observed,and the faster the dissipation of the space charge accumulated in the sample after voltage is removed.In the samples without breakdown,the amount of the slow moving charge reduces as the moisture and temperature rise.In the samples with breakdown,only very small amounts of negative charge accumulate before breakdown.
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2012年第10期2647-2654,共8页
High Voltage Engineering
基金
国家创新研究群体基金(51021005)
国家重点基础研究发展计划(973计划)(2009CB724505-1)~~
关键词
油纸绝缘
空间电荷
水分
温度
电声脉冲(PEA)法
介电强度
oil/paper insulation
space charge
moisture
temperature
pulsed electro-acoustic（PEA） method
dielectric strength
