纳秒脉冲电压下油浸纸局部尖端缺陷击穿特性及损伤规律  

Breakdown Characteristics and Damage Law of Localized Tip Defect on Oil-immersed Paper Under Nanosecond Pulse Voltage

作　　者：李斯盟 杨帆 秦锋[3] 汲胜昌[1] 陈伟[3] LI Simeng;YANG Fan;QIN Feng;JI Shengchang;CHEN Wei(State Key Laboratory of Electrical Insulationand Power Equipment(Xian Jiaotong University)Xiian 710049,Shaanxi Province,China;School of Physics & Information Technology,shanxi Normal University Xi'an710119,Shaanxi Province China;State Key Laboratory of Intense Pulsed Radiation Simulation and Effect(Northwest Institute of Nuclear Technology).Xi'an 710024,Shaanxi Province China)

机构地区：[1]电力设备电气绝缘国家重点实验室(西安交通大学),陕西省西安市710049 [2]陕西师范大学物理学与信息技术学院,陕西省西安市710119 [3]强脉冲辐射环境模拟与效应国家重点实验室(西北核技术研究所),陕西省西安市710024

出　　处：《中国电机工程学报》2022年第14期5326-5337,共12页Proceedings of the CSEE

基　　金：国家自然科学基金项目(52007148);强脉冲辐射环境模拟与效应国家重点实验室开放基金项目(SKLIPR2114)。

摘　　要：配电变压器在高空电磁脉冲(high-altitude electromagnetic pulse,HEMP)早期传导环境中将遭受纳秒电应力入侵,易在绕组引线焊点处造成绝缘失效或损伤。为此,该文研究纳秒脉冲电压下油浸纸尖端缺陷的伏秒特性、击穿概率、脉冲电压幅值与绝缘击穿时脉冲累积次数之间的关系(即U-N特性),并基于放电特性、微观形貌、流注仿真探究纳秒脉冲电压下的油浸纸尖端缺陷损伤规律与机理。研究表明:伏秒特性、击穿概率分布、U-N特性均有明显极性效应,极性效应与界面屏障电荷有关;纳秒脉冲致损油浸纸可分为轻度与重度两个等级,轻度损伤易形成表面斑状缺陷,呈现多次低幅值的工频局部放电模式,重度损伤易形成龟裂缺陷,呈现少次高幅值的工频局部放电模式,损伤差异与油纸界面流注特性有关。结果可为提高配电变压器在HEMP传导环境中的生存能力与评估技术提供一定参考。Distribution transformers suffer from intrusion of nanosecond electrical stress in the early conduction environment of high-altitude electromagnetic pulse(HEMP),which is likely to cause insulation failure or damage at a solder joint of winding.In this paper,the V-t characteristics,breakdown probability,the relationship between pulse voltage amplitude and pulse cumulative times during dielectric breakdown(U-N characteristics) of oil-impregnated paper were studied,with a tip defect under nanosecond pulse voltage.The law and mechanism of paper damage under nanosecond pulse voltage were analyzed based on discharge characteristics,microscopic morphology and streamer simulation.The results show that V-t characteristics,breakdown probability distribution,U-N characteristics have an obvious polar effect,which is related to the interface barrier charge;the pulse-induced damage to oil-impregnated paper can be divided into mild grade and severe grade.Mild damage is prone to form surface spot defects,showing a partial discharge mode with high repetition and low amplitude;severe damage is easy to form cracking defects,showing a partial discharge mode with low repetition and high amplitude.The difference in damage is related to the characteristics of surface streamer.This paper can provide references for improving the survival ability and evaluation techniques for distribution transformers in HEMP environment.

关 键 词：伏秒特性 击穿概率 配电变压器 局部放电 高空电磁脉冲 

分 类 号：TM855[电气工程—高电压与绝缘技术]