干式电力变压器凝胶固化炉的优化设计  

Design Optimization of Gel Curing Oven for Dry-type Transformer Manufacturing

作　　者：张军海 莫向松 郭敬旺 叶彪 Zhang Junhai;Mo Xiangsong;Guo Jingwang;Ye Biao(Guangzhou Yibian Electric Equipment Co.,Ltd.,Guangzhou 511450,China)

机构地区：[1]广州市一变电气设备有限公司,广州511450

出　　处：《机电工程技术》2021年第12期211-215,257,共6页Mechanical & Electrical Engineering Technology

摘　　要：局部放电量是衡量干式电力变压器质量主要指标之一,局部放电量超标时,会影响变压器的运行寿命而危及用电安全。目前常用的凝胶固化炉在凝胶阶段时,沿线圈高度方向上的温度基本是一致的,凝胶时整个线圈同时释放出大量的应力,引起线圈开裂和内部产生气泡从而造成局部放电量增加。因此根据环氧树脂的特性优化线圈的凝胶固化工艺,同时配合工艺对凝胶固化炉的结构进行优化设计,保证凝胶固化炉满足优化后的工艺要求,达到沿线圈高度方向分阶段凝胶和分阶段释放应力的目的,最大限度地降低树脂凝胶时释放的应力,避免线圈在凝胶固化时开裂和在线圈内部产生气泡,从而降低变压器的局部放电量。试验结果表明,采用优化结构的倒梯度凝胶固化炉浇注的线圈,变压器局部放电量可以控制在5 pC以内,远远低于国家标准规定的10 pC限值,可以大幅度提高变压器的运行寿命。Partial discharge is one of the major indexes to evaluate dry-type power transformer’ s quality.Unqualified partial discharge will affect transformer’ s service life and also poses a threat to electrical safety.The gel curing ovens,which are popularly used nowadays,are normally having almost the same temperature at its height direction at the time of gel curing.During gel curing stage,extensive stress will be released concurrently from the whole coil,which will cause cracks on coils.Then,transformer partial discharge is increased.According to the characteristics of epoxy resin,the gel solidification process of the coils was optimized,and the structure of the gel curing furnace was optimized according to the technology.It ensures that the gel curing furnace meets the requirements of the optimized process and achieves the goal of phasing the gel and releasing the stress in stages in the direction of the height along the circle,so as to minimize the stress released during the resin gel.It avoids the cracking of the coil during gel solidification and produces bubbles inside the coil,thereby reducing the local discharge of the transformer.The test results show that the partial discharge capacity of the transformer can be controlled within 5 pC under the optimized structure of the inverted gradient gel solidification furnace,which is far below the 10 pC limit specified in the national standard,and can greatly improve the operation life of the transformer.

关 键 词：变压器 倒梯度 凝胶固化 局部放电 开裂 

分 类 号：TM412[电气工程—电器]