摘要
750 kV油纸电容式套管斜插在变压器箱体上,套管长期受重力影响,内部结构发生应变导致套管内电场畸变,内部电容芯子出现局部放电,加速了套管内部绝缘结构的老化,对套管长期安全稳定的运行有很大影响,因此研究套管在应力作用下的形变与电场强度变化规律之间的关系很有必要。首先建立套管应力理论模型,利用COMSOL在应力有限元模型下仿真运算,得到不同受力情况下套管各位置形变大小,再将不同形变大小的模型在静电场下仿真运算,对比形变前后套管内部的电场分布,发现套管内部电容芯子形变处场强极不均匀,对应变后套管场强不均匀情况进行研究分析得出结论。结果表明:750 kV油纸电容式套管在重力作用下法兰处有明显形变,并且内部电容芯子出现变形,电容芯子均压作用变小,在应变较大时电场畸变程度较大,在靠近法兰处电场畸变最为明显。
750 kV oil paper capacitive bushing is obliquely inserted on the transformer box.The bushing is affected by gravity for a long time,and its internal structure is strained,resulting in the distortion of electric field in the bushing and the partial discharge of the internal capacitor core,which accelerates the aging of the internal insulation structure of the bushing and has a great impact on the long⁃term safe and stable operation of the bushing.Therefore,it is necessary to study the relationship between the deformation of bushing under stress and the variation law of electric field strength.The theoretical model of bushing stress is established,and COMSOL is used to simulate and calculate with the stress finite element model to obtain the deformation size of every position on the bushing under different stress conditions.Then the models with different deformation sizes are simulated and calculated under the electrostatic field condition.The electric field distributions inside the bushing before and after deformation are compared.It is found that the field strength at the deformation of capacitor core inside the bushing is extremely uneven.The non⁃uniformity of bushing field strength after deformation is study and analyzed,and a conclusion is achieved.The results show that there is obvious deformation at the flange of 750 kV oil paper capacitive bushing under the action of gravity,the internal capacitor core is deformed,and the equalizing pressure effect of the capacitor core becomes smaller.The degree of electric field distortion is large when the strain is large,and the electric field distortion near the flange is the most obvious.
作者
郑义已
赵洪峰
ZHENG Yiyi;ZHAO Hongfeng(School of Electrical Engineering,Xinjiang University,Urumqi 830017,China)
出处
《现代电子技术》
2022年第23期156-160,共5页
Modern Electronics Technique
基金
国家自然科学基金项目(51762038)。
关键词
变压器套管
电容芯子
变压器箱体
应力应变
有限元分析软件
电场畸变
绝缘结构
transformer bushing
capacitor core
transformer box
stress and strain
finite element analysis software
electric field distortion
insulation structure
