面向SF_(6)气体绝缘设备故障检测的光声CO气体传感器设计和优化  

Design and optimization of photoacoustic CO gas sensor for fault diagnosis of SF_(6) gas insulated equipment

作　　者：尹旭坤 董磊[3] 武红鹏[3] 刘丽娴 邵晓鹏[1,2] Yin Xu-Kun;Dong Lei;Wu Hong-Peng;Liu Li-Xian;Shao Xiao-Peng(Xi’an Key Laboratory of Computational Imaging,Xidian University,Xi’an 710071,China;School of Physics and Optoelectronic Engineering,Xidian University,Xi’an 710071,China;State Key Laboratory of Quantum Optics and Quantum Optics Devices,Institute of Laser Spectroscopy,Shanxi University,Taiyuan 030006,China)

机构地区：[1]西安电子科技大学,西安市计算成像重点实验室,西安710071 [2]西安电子科技大学物理与光电工程学院,西安710071 [3]山西大学,激光光谱研究所,量子光学与光量子器件国家重点实验室,太原030006

出　　处：《物理学报》2021年第17期76-82,共7页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:62075119,61975254,61805187,61805132);广东省基础与应用基础研究基金(批准号:2020A1515111012)资助的课题.

摘　　要：针对电力系统对六氟化硫电气绝缘设备中气体衍生物的在线高精度探测需要,提出了差分双通道结构的光声池作为光声探测模块,并使用中心波长为2.3μm的分布式反馈(distributed feedback laser,DFB)激光器作为激励光源,搭建了一款工作在高浓度六氟化硫背景气体中的一氧化碳气体传感器.通过光声共振理论模拟和设计,在纯六氟化硫气体中光声池的品质因子为84,相对于在氮气载气中的品质因子提高了约4倍.经实验验证,差分结构光声池的最大气体流速较单共振腔光声池提高了6倍,且具有较强的噪声免疫能力.在对传感器系统的共振频率、气流速度和工作压强等参数优化后,在1 s的积分时间下,获得一氧化碳气体的探测灵敏度为体积分数1.18×10^(-6),对应的归一化噪声等效浓度(1σ)为3.68×10^(-8) cm^(-1)·W·Hz^(-1/2).该传感器的灵敏度高,选择性好且噪声免疫能力强,可以为电力系统中潜在性绝缘故障诊断提供一种在线探测技术,具有重要的应用前景.Trace gas analysis for SF_(6)decomposition is a powerful diagnostic method to identify partial discharge problem occurring in electrical equipment.In particular,it is recognized that the SF_(6)decomposition gases(such as CO,H_(2)S,SO_(2)and CF_(4))can effectively determine the inner insulation condition of the electrical equipment.Currently,most of researches of diagnostic methods cannot meet the online high-precision detection of gas derivatives in SF_(6)electrical insulation equipment.Therefore,there is a need of developing a sensitive,selective and cost-effective sensor system for CO detection in an SF_(6)buffer gas environment due to the fact that the power system is filled with pure SF_(6)as the dielectric gas,which means that the concentration of SF_(6)is usually>99.8%.The traditional photoacoustic CO gas sensors cannot be directly used in power system,since several SF_(6)physical constants strongly differ from those of N2 or air.In addition,SF_(6)molecule reveals uninterrupted and strong absorption lines in the mid-infrared spectral region.In this work,a CO gas sensor working in high concentration SF_(6)background gas is designed by using a distributed feedback(DFB)laser as an excitation source with a center wavelength of 2.3μm.The absorption line strength of 2.3μm is~two orders of magnitude higher than the absorption line strength around 1.56μm,which can improve the sensor detection performance.A background-gas-induced high-Q differential photoacoustic cell is simulated numerically and tested experimentally.The quality factor of the designed photoacoustic cell in pure SF_(6)gas is 85,which is~4 times higher than that in N2 carrier gas.The experimental results show that the maximum gas flow rate of the differential structure photoacoustic cell is~6 times higher than that of the single resonant cavity photoacoustic cell.After optimizing the resonance frequency,gas velocity and working pressure of the sensor system,the detection sensitivity of the volume fraction of 1.85×10^(-6)is achieved.In the case of

关 键 词：光声光谱 痕量气体传感器 电气设备绝缘诊断 

分 类 号：TM855[电气工程—高电压与绝缘技术]