摘要
目前,色谱柱和气敏传感器已广泛应用于变压器油中溶解气体在线监测装置中。但这些装置存在消耗载气、需定期标定的不足。基于傅里叶红外技术的气体分析具有准确度高、免标定、免消耗气体的优点,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。设计了“流动气体法”实验装置,针对故障诊断中最重要的C2H2,用傅里叶红外光谱仪采集了吸收谱;对输出特性进行了曲线拟合,并讨论了浓度范围和定量特征的选取对定量准确度的影响;此外,还试验了傅里叶红外光谱的最低检测限。实验及计算结果表明,在低浓度区用峰高度、高浓度区用峰面积作为定量特征,用三次多项式对傅里叶红外光谱的输出特性进行拟合,有利于提高准确度;使用2.4m气体池的最低检测限可以达到0.3μL/L以下,10cm气体池的最低检测限在3μL/L以下。
Currently, the chromatographic column and gas sensor are widely used in online monitoring devices of dissolved gases in transformer oil. But there exist disadvantages with these devices, such as, the consumption of carrier gas, the requirement of regular calibration, etc. Since FTIR （Fourier transform infrared） is highly accurate, consumes no carrier gas and requires no calibration, the application of FTIR in such monitoring devices is studied. Experiments on the “flow gas method” have been designed. And the FTIR spectrometer is used to collect the infrared spectra of C2H2, which is the most important gas for transformer fault diagnosis. Curve fitting of the output of FTIR is performed, and the effects of quantitative characteristics and concentration range on the quantitative analysis are discussed. In addition, the lowest detection limit to FTIR is tested. Experiment and calculation results show, that by taking the peak height in the low concentration range or peak area in the high concentration range as the quantitative characteristic, using the cubic polynomial to fit the output curve of FTIR, the accuracy can be improved. The lowest detecting limit with 2.4 m gas cell is below 0.3 μL/L and that of 10 cm gas cell is below 3μL/L.
出处
《电力系统自动化》
EI
CSCD
北大核心
2005年第18期62-65,共4页
Automation of Electric Power Systems
基金
中国博士后科学基金资助项目宁波市重点博士基金资助项目。
关键词
变压器
在线监测
傅里叶红外光谱
油中溶解气体
transformer
online monitoring
Fourier transform infrared （FTIR）
dissolved gases in oil
