摘要
运行变压器油中溶解微量乙炔气体含量能有效反映变压器内部的过热与放电故障;光声光谱气体检测是实现其在线监测的有效手段。传统的光声光谱采用电麦克风检测气体产生的光声信号,微弱的电学信号易受到变压器周围强电磁环境的干扰,严重影响微量气体检测的稳定性和灵敏度。论文开展微量乙炔气体光纤F-P传声光声光谱检测研究,结合光纤激光功率放大技术,将乙炔特定波长处的激发光功率由20 mW提高到了200 mW;制作了悬臂梁F-P光纤声传感器探头匹配共振光声池共振频率,实现悬臂梁与共振光声池的双共振增强;采用波长调制以气体光声信号二次谐波幅值检测气体浓度;搭建了基于光纤F-P光纤声传感器的乙炔气体光声光谱检测平台,实现了微量乙炔气体的稳定检测,线性度好,拟合优度为0.99,体积分数检测极限达15×10-9。
The concentration of trace ethyne gas dissolved in transformer oil can adequately reflect whether overheating and discharge failures occur inside the transformer.Photoacoustic spectroscopy is becoming an effective monitoring method for online gas detection.However,in traditional photoacoustic spectroscopy,electric microphones are usually used to detect the photoacoustic signals.Weak electrical signals are easily affected by the strong electromagnetic field environment around the transformer,which seriously affects the stability and sensitivity of trace gas detection.We researched the detection of trace ethyne by photoacoustic spectroscopy based on fiber-optic acoustic sensors.Combined with fiber laser power amplification technology,the excitation light power at an absorption wavelength of ethyne was increased from 20 m W to 200 mW.The fiber-optic cantilever acoustic sensor head was made to match the resonance frequency of the resonance photoacoustic cell,which realized the dual resonance enhancement of the cantilever and the resonance photoacoustic cell.Wavelength modulation technology was used to detect the gas concentration with the second harmonic amplitude of the photoacoustic signal.The photoacoustic spectroscopy system based on fiber-optic acoustic sensors was built for trace ethyne detection,and stable detection of trace ethyne with good linearity,goodness of fit of 0.99,and detection limit of 15×10-9 could be realized.
作者
杨天荷
陈伟根
李志军
YANG Tianhe;CHEN Weigen;LI Zhijun(State Key Laboratory of Power Transmission Equipment&System Security and New Technology,Chongqing University,Chongqing 400044,China;Jiangsu Guodian Nanjing Automation Haiji Technology Co.,Ltd,Nanjing 211153,China)
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2020年第6期1922-1928,共7页
High Voltage Engineering
基金
国家自然科学基金(U1766217)。
关键词
乙炔气体
光声光谱
光纤F-P声传感器
悬臂梁
稳定检测
ethyne
photoacoustic spectroscopy
fiber-optic acoustic sensor
cantilever
stability testing
