SF_6气体中金属尖端在振荡冲击电压下的局部放电特性  

Characteristics of Partial Discharges at Metal Protrusion Under Oscillating Impulse Voltages in SF_6 Gas

作　　者：黄军凯 刘崇斌 刘华麟 任明[2] 张崇兴[2] 董明[2] 

机构地区：[1]贵州电力试验研究院,贵阳550005 [2]西安交通大学电力设备电气绝缘国家重点实验室,西安710049

出　　处：《高电压技术》2015年第11期3872-3880,共9页High Voltage Engineering

基　　金：国家自然科学基金(51507130);中国博士后基金(2014M560777)~~

摘　　要：随着气体绝缘开关设备(GIS)现场冲击耐压试验的推广实施,冲击电压下的局部放电检测被作为1种新方法而应用于GIS的现场绝缘诊断,但冲击电压下的局部放电仅被认为是击穿前的预放电现象而缺乏全面深入的研究。为此,建立了冲击电压下的局部放电(PD)宽频带光、电脉冲检测系统,采用标准振荡雷电冲击(OLI)和标准振荡操作冲击(OSI)作为激励源,对针尖曲率半径为25μm、100μm和500μm的金属尖端缺陷在SF6气体中的局部放电行为和统计分布特性进行了研究,并在此基础上针对人工预置金属尖端缺陷的实际GIS试品进行了模拟试验。试验研究发现单次脉冲型放电、紧密的多脉冲放电、稀疏的多脉冲放电、反极性放电及预击穿放电共5种具有典型特征的光、电脉冲(序列);各类放电的出现概率受气压、电压及缺陷尺寸的变化的影响虽具有随机性,但仍然具备可统计性;GIS的模拟局部放电检测表明,2种振荡冲击电压均能够有效检测GIS内部的尖刺类缺陷,其局部放电检测效率高于工频交流电压。As the impulse withstanding test for gas insulated switchgear （GIS） is widely used in field, partial discharge detection under impulse voltage is considered as a new diagnosis method for insulation of GIS. Until now, the partial dis- charge under impulse voltage is viewed as pre-discharge before breakdown, and its characteristics are still remaining elusive. As a result, we built a wideband partial discharge （PD） detection system, by which the emission light intensity and current signal could be obtained. Moreover, we investigated the PD behaviors and the statistical distributions in SF6 gas from metal tip defects with radii of 25 μm, 100 μm, and 500 μm under standard oscillating lightning impulse （OLI） and oscillating switching impulse （OSI） voltage. Thereby, an actual GIS with artificial protrusion defect was tested. By using experimental data, we summarized the single pulse discharge, intensive multi-pulse discharge, spare multi-pulse discharge, reverse polarity discharge, and the pre breakdown discharge PD sequences. It is found that their occurrence probabilities varying with the voltage level, the gas pressure, and the dimension of protrusion defect are still statistical. The PD tests on actual GIS demonstrate that OLI and OSI voltages have greater efficiency than power frequency AC vol- tage in exciting PDs from protrusion defects in GIS.

关 键 词：振荡雷电冲击电压 振荡操作冲击电压 六氟化硫 GIS OLI OSI 局部放电 放电特性 

分 类 号：TM595[电气工程—电器]