变压器油中溶解气体拉曼光谱检测及其光谱线型模型分析

拉曼光谱气体检测技术能利用单一波长的激光对气体样品进行无接触、无损耗检测，适用于油浸式变压器油中溶解气体检测。结合拉曼光谱检测机理，分析了拉曼光谱谱线特征，建立了由洛仑兹函数与高斯函数卷积表示的拉曼光谱Voigt线型模型，其表现出较好的拉曼谱峰线型轮廓基本特征。以谱峰高、中心位置、半峰全宽等为代表的拉曼谱峰线型轮廓基本特征是寻峰的主要目标，其根本目的在获取样本定性及定量检测分析依据。故针对拉曼光谱实验数据设计了基于比较法的自动寻峰模型以实现检测目标。对引入到Voigt线型模型中的寻峰模型进行的模拟实验结果表明，模拟中谱峰高、中心位置等数据均与模型输出数据相吻合。依托实验室构建的变压器油中溶解气体拉曼光谱检测平台，分析检测实验数据表明，Voigt线型模型中半峰全宽参数实际取值区间为(8.7，11.5)(cm-1)，模型与其存在偏差。修正该参数取值为10.257 cm-1，并对比研究表明：修正后的Voigt线型模型及寻峰模型具有更好的适应性及实用性。结合实验平台的拉曼光谱气体检测数据的寻峰结果，有效地完成了七种变压器故障特征气体的检测及分析。针对甲烷气体，获得单位气体含量、拉曼特征峰强度与面积三者之间的线性关系，为变压器油中溶解气体拉曼光谱检测定量分析奠定基础。

The Detection of Raman Spectra on Dissolved Gas in Transformer Oil and Its Spectral Linear Model Analysis

Raman spectroscopy gas detection technology which uses a single wavelength laser detection of gas samples without contact and loss is suitable for dissolved gas detection in oil-immersed transformers.Combined with the features of Raman spec-tral lines,the analysis of the detection mechanism in Raman spectroscopy technology has been made.Raman spectral lines have been presented in the expression of the convolution of Lorentz function and Gaussian function,which shows preferable Raman spectrum peak linear outline basic characteristics.In this paper,the basic features of the peak height,the peak position and the half peak width,are the main targets of peak searching,and the fundamental purpose of this paper is to obtain qualitative and quantitative analysis of the sample.Therefore,the experimental data of Raman spectroscopy is designed based on the comparison method to realize the automatic peak seeking model to achieve the detection target.Therefore,according to the automatic peak searching model based on the comparison method is designed to achieve the detection target.The simulation results of using peak searching model in the Voigt linear model show that spectrum peak height and peak position are in conformity with the theory in the test experiment.Based on the establishment of Raman spectroscopy detection platform aiming at the dissolved gas in trans-former oil,the analysis of the experimental data show that the actual values of the half peak height and width are (8.7,1 1.5) (cm-1 )in the Voigt linear model with deviations.Setting the value as 10.257 cm-1 to modify the parameter,then compared with the research results,it shows that the modified Voigt linear model and the peak searching model have better adaptability and practicability.Combined with the gas detection in the experimental platform in the experimental platform of Raman spectrosco-py,detection of seven kinds of transformer fault characteristic gas and analysis of peak searching have been completed effectively. In terms of methane gas,the linear relationship among the unit gas content,Raman characteristic peak intensity and the area has been obtained,which has laid a foundation for the quantitative analysis of the dissolved gas in transformer oil.