摘要
局部放电量是衡量变压器质量的一个重要指标,局部放电量过大,会缩短变压器运行寿命。目前国内变压器厂家在浇注绕组时,凝胶阶段绕组纵向温度相同,凝胶时绕组纵向同时释放出大量应力,树脂易开裂,且绕组内微量气泡不易排除,会增大绕组局部放电量。通过对环氧树脂成分比例、收缩率、导热率、玻璃化转变温度、填料沉淀、机械性能等特性的分析,在凝胶时沿绕组纵向方向温度从下到上逐渐降低,绕组从下往上分阶段凝胶,树脂释放的应力大大降低,有效防止绕组开裂,降低绕组的局部放电量,局部放电量可控制在5 pC以内,低于国家标准规定的10 pC限值。
Partial discharge is an important index to measure the quality of transformer,excessive partial discharge will shorten the service life of transformer.At present,when the transformer manufacturers are pouring the windings,the longitudinal temperature of the winding in the gel stage is the same,when the gel is exposed,a large amount of stress is released in the longitudinal direction of the winding,the resin is easy to crack,and the micro bubbles in the winding are not easy to be eliminated,which will increase the local discharge of the winding.By analyzing the composition ratio,shrinkage rate,thermal conductivity,glass transition temperature,filler precipitation and mechanical properties of epoxy resin,the temperature in the longitudinal direction of the gel was gradually decreased from the bottom to the top,and the stress of the resin was greatly reduced from the bottom to the top,the cracking of the winding was effectively prevented and the local discharge of the winding was reduced.The partial discharge can be controlled within 5 pC,which is lower than the limit of 10 pC stipulated by the national standard.
作者
张军海
彭景伟
余小平
廖冬虹
叶彪
Zhang Junhai;Peng Jingwei;Yu Xiaoping;Liao Donghong;Ye Biao(Guangzhou Yibian Electrical Equipment Co.,Ltd.,Guangzhou 511450,China)
出处
《机电工程技术》
2020年第11期243-246,共4页
Mechanical & Electrical Engineering Technology
关键词
环氧树脂
特性分析
工艺
开裂
局部放电量
epoxy resin
characteristic analysis
process
cracking
partial discharge
