基于分布反馈半导体激光器的CO气体光声光谱检测特性

一氧化碳(CO)是变压器油中溶解的主要故障特征气体之一,能有效反映运行电力变压器中油纸绝缘的放电及老化;而光声光谱(photoacoustic spectroscopy,PAS)技术能够应用于变压器油中溶解气体的在线监测。基于光声光谱检测原理,利用分布反馈(distributed feedback,DFB)半导体激光器搭建了CO气体光声光谱检测平台,选择1.567m的CO分子谱线为研究对象,实验研究了DFB半导体激光器的辐射特性和CO气体的光声光谱响应特性,分析了光声信号与激光功率、气体浓度的关系。结果表明:在气体吸收未发生饱和效应的条件下,光声信号与激光功率、气体浓度均具有良好的线性关系。该研究结果为变压器油中气体光声光谱的在线监测奠定了基础。

Characteristics of Photoacoustic Spectroscopy Detection for Carbon Monoxide Gas Based on DFB Diode Laser

Carbon monoxide gas is one of the main fault feature gases dissolved in transformer oil,which can effectively reflect the performance of discharge and aging of oil-paper insulation in running power transformers.Photoacoustic spectroscopy(PAS) can well be used in on-line monitoring of the gas dissolved in transformer oil.A carbon monoxide detection experimental platform with a distributed feedback(DFB) diode laser was developed based on the PAS fundamental.The molecular spectral line of carbon monoxide at 1.567??m was investigated in this paper.The radiation properties of DFB diode laser and the response characteristics of PAS for carbon monoxide were studied.Also functional relations between photoacoustic signal and laser power,gas concentration were discussed.The experimental results show that when gas absorption saturation effect does not occur,photoacoustic signal has a good linear dependence on laser power and gas concentration,and this lays a foundation for the on-line photoacoustic monitoring of gas dissolved in transformer oil.