基于脉冲电流信号的大型电力变压器极不均匀电场油隙贯穿性放电特性  

Characteristics of Oil Gap Penetration Discharge in Large Power Transformers With Extremely Non-uniform Electric Field Based on Pulse Current

作　　者：任达 郑玉平 李斯盟 潘书燕[4] REN Da;ZHENG Yuping;LI Simeng;PAN Shuyan(State Grid Electric Power Research Institute,Nanjing 211106,Jiangsu Province,China;State Key Laboratory of of Risk Defense Technology and Equipment for Power Grid Operation(SGEPRI),Nanjing 211106,Jiangsu Province,China;State Key Laboratory of Electrical Insulation and Power Equipment(Xi’an Jiaotong University),Xi’an 710049,Shaanxi Province,China;Nari Technology Development Limited Company,Nanjing 211106,Jiangsu Province,China)

机构地区：[1]国网电力科学研究院有限公司,江苏省南京市211106 [2]电网运行风险防御技术与装备全国重点实验室(国网电力科学研究院有限公司),江苏省南京市211106 [3]电工材料电气绝缘全国重点实验室(西安交通大学),陕西省西安市710049 [4]国电南瑞科技股份有限公司,江苏省南京市211106

出　　处：《中国电机工程学报》2025年第9期3332-3345,I0005,共15页PROCEEDINGS OF THE CHINESE SOCIETY FOR ELECTRICAL ENGINEERING

基　　金：国家电网有限公司科技项目(5100-202340030A-1-1-ZN)。

摘　　要：为深入研究大型电力变压器真实环境中的极不均匀电场严重放电特性,该文搭建110 kV真型变压器试验平台,监测油纸绝缘针板电极放电发展过程,对放电现象分类归纳,总结油隙贯穿性放电的脉冲电流信号特征,结合特高频信号进一步探索不同极性下油隙贯穿性放电通道的演变过程。结果表明:在油纸绝缘结构中,存在纸板屏障下的油隙击穿现象,是严重放电的重要表现;在极不均匀电场中,不同极性的油隙贯穿性放电形貌存在明显差异且呈现出不同序列的簇状脉冲电流特征;油隙贯穿性放电通道演变过程有着类似长空气间隙放电过程,正极性油隙贯穿性放电通道演变过程可以划分为初始电晕向放电通道转换和连续放电通道发展两个阶段,其中连续放电通道发展过程中可能出现放电通道熄灭现象;负极性油隙贯穿性放电通道演变过程可以划分为初始电晕和连接过程两个阶段,连接过程中伴随有不等时间间隔的空间梯级放电。结果可为大型电力变压器放电特性试验以及物理模型研究提供参考。To investigate the severe discharge characteristics of highly non-uniform electric fields in practical large power transformer environments,a 110kV real transformer testing platform is built.The discharge process of needle plate electrodes is monitored and the discharge phenomena are classified.The pulse current characteristics of the oil gap penetration discharge are summarized The evolution process of oil gap penetrating discharge channels under different polaritiesis is explored by combining the characteristics of ultra high frequency.The research show that there is a phenomenon of oil gap breakdown in the cardboard barrier,which is an important manifestation of severe discharge in the oil-paper insulation structure.There are significant differences in the shape of the oil gap penetrating discharge with different polarities,and it exhibits cluster-like pulse currents with different pulse sequences of extremely non-uniform electric field.The evolution process of the oil gap penetrating discharge channel is similar to the development process of long air gap discharge.The evolution process of discharge channels under positive polarity can be divided into two stages:the initial corona transition to discharge channel and the continuous discharge channel development.The phenomenon of discharge channel extinction may occur during the development of continuous discharge channels.The evolution process of discharge channels under negative polarity can be divided into two stages:the initial corona and the connection process.There are spatial step discharges with unequal time intervals during the connection process.This paper can provide reference for the discharge characteristic test and physical model research of large power transformers.

关 键 词：大型电力变压器 油隙贯穿性放电 放电通道 脉冲电流 极不均匀电场 

分 类 号：TM855[电气工程—高电压与绝缘技术]