Chen Xin-gang, Li Song, Ma Zhi-peng, Ni Zhi, Yang Ding-kun, Tan Hao
Guang Pu Xue Yu Guang Pu Fen Xi. 2016 Aug;36(8):2492-8.
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 spectral 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 transformer oil, the analysis of the experimental data show that the actual values of the half peak height and width are (8.7，11.5)(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 spectroscopy,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.
拉曼光谱气体检测技术采用单波长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中溶解气体的检测。结合拉曼光谱线的特征，对拉曼光谱技术的检测机理进行了分析。拉曼光谱线以洛伦兹函数和高斯函数卷积的形式呈现，展现出较好的拉曼光谱峰线性轮廓基本特征。本文以峰高、峰位和半峰宽的基本特征作为寻峰的主要目标，目的是对样品进行定性和定量分析。因此，基于比较法设计拉曼光谱实验数据，实现自动寻峰模型以达到检测目标。所以，根据基于比较法的自动寻峰模型进行设计以实现检测目标。在Voigt线性模型中使用寻峰模型的仿真结果表明，在测试实验中光谱峰高和峰位与理论相符。基于针对变压器油中溶解气体建立的拉曼光谱检测平台，对实验数据分析表明，在Voigt线性模型中半峰高和半峰宽的实际值为(8.7, 11.5)(cm-1)，存在偏差。将该值设为10.257 cm-1来修正参数，与研究结果对比表明，修正后的Voigt线性模型和寻峰模型具有更好的适应性和实用性。结合拉曼光谱实验平台中的气体检测，有效完成了七种变压器故障特征气体的检测及寻峰分析。对于甲烷气体，得出了单位气体含量、拉曼特征峰强度与面积之间的线性关系，为变压器油中溶解气体的定量分析奠定了基础。
