Wang Pinyi, Chen Weigen, Wang Jianxin, Tang Jun, Shi Yongli, Wan Fu
State Key Laboratory of Power Transmission Equipment & System Security and New Technology, Chongqing University, No. 174, Shazheng Street, Chongqing, 400044, China.
State Grid Sichuan Electric Power Company, No. 18, Jiaozi North Second Road, Chengdu, 610041, China.
Anal Chem. 2020 Apr 21;92(8):5969-5977. doi: 10.1021/acs.analchem.0c00179. Epub 2020 Apr 1.
We demonstrate the utility of cavity-enhanced Raman spectroscopy (CERS) as a unique multigas analysis tool for power transformer diagnosis. For this purpose, improvements have been added to our recently introduced CERS apparatus. Based on optical feedback frequency-locking, laser radiation is coupled into a high-finesse optical cavity, thus resulting in huge intracavity laser power. With 20 s exposure time, ppm-level gas sensing at 1 bar total pressure is achieved, including carbon dioxide (CO), carbon monoxide (CO), hydrogen (H), methane (CH), ethane (CH), ethylene (CH), acetylene (CH), nitrogen (N), and oxygen (O). By using the internal standard gas (sulfur hexafluoride, SF), the quantification of multigas with high accuracy is also realized, which is confirmed by the measurement of calibration gases. For fault diagnosis, transformer oil is sampled from a 110 kV power transformer in service. Dissolved gases are extracted and analyzed by the CERS apparatus. Then the transformer is diagnosed according to the measurement results. CERS has the ability to analyze multigas with high selectivity, sensitivity, and accuracy, it has great potential in gas sensing fields.
我们展示了腔增强拉曼光谱（CERS）作为一种用于电力变压器诊断的独特多气体分析工具的实用性。为此，我们对最近推出的CERS装置进行了改进。基于光反馈频率锁定，激光辐射被耦合到一个高精细度光学腔中，从而产生巨大的腔内激光功率。在20秒的曝光时间下，在总压力为1巴时可实现ppm级的气体传感，包括一氧化碳（CO）、二氧化碳（CO₂）、氢气（H₂）、甲烷（CH₄）、乙烷（C₂H₆）、乙烯（C₂H₄）、乙炔（C₂H₂）、氮气（N₂）和氧气（O₂）。通过使用内标气体（六氟化硫，SF₆），还实现了多气体的高精度定量，这通过校准气体的测量得到了证实。为了进行故障诊断，从一台运行中的110 kV电力变压器中采集变压器油。提取溶解气体并通过CERS装置进行分析。然后根据测量结果对变压器进行诊断。CERS具有高选择性、高灵敏度和高精度分析多气体的能力，在气体传感领域具有巨大潜力。
