基于密度泛函理论的油中溶解气体拉曼特征频谱分析

Analysis of the Raman Shifts of Gases Dissolved in Transformer Oil Based on the Density Functional Theory

为了准确获取电力变压器的运行状态,对其进行有效的维护,文中针对7种变压器故障气体的拉曼特征频谱选择,建立了基于密度泛函理论(DFT)中B3LYP方法的气体分子构型优化和拉曼频移特征仿真分析,并结合搭建的拉曼实验平台;对相等含量的7种故障气体完成拉曼检测,结合密度泛函理论与实际检测,确定7种故障气体H_2、CH_4、C_2H_6、C_2H_4、C_2H_2、CO、CO_2的特征拉曼频移分别为:4 155、2 924、2 954、1 346、1 976、2 142、1 390 cm^(-1)。此结果已将得到故障气体实测拉曼频移与校正拉曼频移偏差率控制在±3%以内,为故障气体种类的快速判别及定量分析打下基础。

In order to accurately obtain the running state of power transformers and maintain effectively, the molec- ular configuration optimization and the simulations of the 7 kinds of fault gases have been done based on the B3LYP method of the density functional theory （DFT）. Combined with the Raman experimental platform, Raman detection of the seven kinds of fault gases is made under the condition that the concentration is the same. Accord- ing to some certain principles, the Raman shifts of the seven kinds of fault gases （H2,CH4,C2H6,C2H4,C2H2,CO, CO2） are determined respectively： 4 155,2 924,2 954,1 346,1 976,2 142,1 390 cm^-1. The observed Raman fre- quency and the corrected Raman frequency which is obtained by calculations and analysis are compared, and the deviation rate is within ±3%. This lays the foundation for the fast determination of the gases and the quantitative analysis.