光声光谱技术在油浸式电气设备故障气体检测中的应用

光声光谱气体检测技术具有精度高、检测范围宽、不消耗被测气体和载气等优点,适用于油浸式电气设备油中溶解气体的在线监测。对气体光声信号的产生机理进行了理论研究,分析了油中溶解气体的红外光谱特性。基于顶空脱气和光声光谱监测技术,构建了油中溶解气体在线监测平台。结合平台对标准气样和标准油样进行重复性和准确度的测试。采集实际运行的变压器中的油样,与实验室的气相色谱仪进行对比测试,结果都达到或优于电力系统油中溶解气体在线检测的要求,能有效地检测油浸式电器设备油中溶解气体含量。

Dissolved gas analysis in oil-immersed electrical equipment based on photoacoustic spectroscopy

Photoacoustic spectroscopy (PAS) has the advantages of high precision, wide detection range, no consumption of measured gas and carrier gas. It can be applied to online monitoring dissolved gas in oil for oil immersed electrical equipment. This paper analyzes the generation mechanism of gas photoacoustic signal and the spectral characteristics of dissolved gases in insulation oil. An experimental gas detection platform is devised by coupling dynamic headspace degassing with photoacoustic spectroscopy. This platform is tested with standard gas samples and standard oil sample for repeatability and accuracy tests, and an oil sample is collected from a transformer in practical operation, and the results are compared with those of a laboratory gas chromatograph (GC) system. The results meet or exceed the standards for online detection of dissolved gas in power system. Consequently, the proposed technique effectively detects dissolved gas in oil for oil-immersed electric equipment.