光声光谱技术应用于变压器油中溶解气体分析

变压器油中溶解气体在线监测装置中的色谱柱和气敏传感器存在消耗被测气体和长期稳定性差等不足.光声光谱气体分析技术灵敏度高,不消耗被测气体,克服了传统油中溶解气体在线监测技术的缺点.文中对其在变压器油中溶解气体在线监测中的应用进行了研究.构建了用于变压器油中溶解气体分析的光声光谱平台,给出具有红外特征吸收峰的CH4,C2H6,C2H4,C2H2,CO和CO2这6种主要故障特征气体的特征频谱,采用加权最小二乘法对2种混合气体中的CH4,C2H6,C2H4,C2H2,CO和CO2进行了定性和定量分析.分析结果与气体各组分体积分数真实值或气相色谱仪测量值的比较表明,光声光谱技术能有效地对变压器油中溶解气体进行分析.

Gas-in-oil Analysis in Transformers Based on Photoacoustic Spectrometry

Chromatographic columns and gas sensors used in online monitoring devices of dissolved gases in transformer oil have some disadvantages such as the consumption of carrier gas and the failure of long stability. Photoacoustic spectrometry (PAS) is a highly sensitive gas analyzing method without the shortcoming of gas consumption, thus overcoming the disadvantages of the previous online monitoring methods. An investigation is made on the application of PAS in analyzing dissolved gases in transformer oil and a device based on PAS has been designed for the gas-in-oil analysis. The infrared characteristic spectra of CH4, C2H6, C2H4, C2H2, CO and CO2 are given and the weighted least square method is adopted for the quantitative analysis of CH4, C2H6, C2H4, C2H2, CO and CO2 in the mixture consisting of two gases. The analysis results are compared with the actual concentrations and those measured by gas chromatography. The comparison results show that PAS is effective in analyzing dissolved gases in transformer oil. Hence fine prospects for its application in on-line monitoring of such gases.