基于光声光谱技术的SF6/N2故障分解气体检测中SF6含量对检测灵敏度的影响  

Influence of SF6 Concentration in SF6/N2 Gas Mixture on Decomposition Products Analysis Based on Photoacoustic Spectrometry Detection

作　　者：李康[1] 马凤翔 朱会 朱峰 韩冬[1,4] Li Kang;Ma Fengxiang;Zhu Hui;Zhu Feng;Han Dong(Institute of Electrical Engineering Chinese Academy of Sciences,Beijing,100190,China;State Grid Anhui Electric Power Co.Ltd,Hefei,230022,China;Henan Relations Co.Ltd,Zhengzhou,450001,China;University of Chinese Academy of Sciences,Beijing,100190,China)

机构地区：[1]中国科学院电工研究所,北京100190 [2]国网安徽省电力有限公司电力科学研究院,合肥230022 [3]河南省日立信股份有限公司,郑州450001 [4]中国科学院大学,北京100190

出　　处：《电工技术学报》2020年第17期3773-3780,共8页Transactions of China Electrotechnical Society

基　　金：国家重点研发计划(2017YFB0902500);国家电网有限公司科技项目(521205190014)资助。

摘　　要：由于各方面性能均衡,SF6/N2混合气体是目前替代SF6气体的最佳选择之一,许多电力设备已经采用SF6/N2混合气体作为绝缘介质。电力公司的运检人员开始关注SF6/N2混合气体故障分解产物的检测问题,如采用现有的光声光谱仪器是否可以继续检测分解气体,检测灵敏度如何等。针对上述问题,该文首先从光声光谱基本原理出发,指出背景气体改变主要影响光声光谱系统的光声池常数,且随着混合气体中SF6比例降低,光声池常数增大,有利于分解气体的检测。混合气体中SF6比例从100%变为20%,光声池常数由168.7 Pa·cm/W增大至576.0 Pa·cm/W。然后搭建光声光谱实验平台,对比不同SF6混合比条件下,SO2、CO2、CO、CF4和SO2F2五种气体组分的最低检测限,实验结果与理论分析趋势一致,即SF6气体比例越小,最低检测限越低,越容易检测。SF6比例从100%变为30%,分解气体中CO2最低检测限可由0.629×10^-4%减小至0.226×10^-4%。Due to the balanced performance of various aspects,SF6/N2 gas mixture is one of the best alternatives to SF6 gas.Many power apparatuses have adopted SF6/N2 gas mixture as insulation medium.Therefore,the maintainers of the power company began to pay attention on the detection of the decomposition products of SF6/N2 gas mixture,such as whether the existing photoacoustic instruments can detect the decomposition gas,and how is the detection sensitivity?In view of the above problems this paper analyses the influence of background gas based on the basic principle of photoacoustic spectroscopy in the beginning.It is pointed out that the change of background gas mainly affects the photoacoustic cell constant of photoacoustic spectrometry system.With the decrease of SF6 ratio in mixed gas,the photoacoustic cell constant increases,which is beneficial to gas detection.The ratio of SF6 changed from 100%to 20%,the photoacoustic cell constant increased from 168.7Pa·cm/W to 576.0Pa·cm/W.Then a photoacoustic spectrometry experimental platform was built to compare the minimum detection limits of SO2,CO2,CO,CF4 and SO2F2 under different SF6 mixing ratios.The experimental results are consistent with the theoretical analysis.The smaller the ratio of SF6 gas,the smaller the minimum detection limit and the easier it is to detect.The SF6 ratio changed from 100%to 30%,the minimum detection limit of CO2 in decomposition gas decreased from 0.629 ppm to 0.226 ppm.

关 键 词：光声光谱 光声池常数 最低检测限 SF6/N2 混合气体 故障分解气体 

分 类 号：TM315[电气工程—电机] TM595