Simultaneous and Dynamic Detection of SF6 Decomposition Products Under Partial Discharge Defect of Gas-Insulated Power Equipment by Fiber-Enhanced Raman Spectroscopy

SF6 decomposition product analysis can effectively obtain the health status of gas-insulated power equipment (GIPE). In this article, to solve the drawbacks of aging, cross-interference, and time-sharing detection analysis of common gas detection technologies, a fiber-enhanced Raman spectroscopy (FERS) sensing system is used to realize the simultaneous and dynamic measurement of multiple SF6 decomposition products. A hybrid collaborative fluorescence filtering method (HCFFM) is proposed to simply and effectively improve the sensitivity of FERS by 2.7 times. The characteristic peaks for simultaneous quantitative and qualitative determination of SF6 decomposition products are determined (811 cm−1 for SOF2, 851 cm−1 for SO2F2, 861 cm−1 for COS, 913 cm−1 for CF4, 1156 cm−1 for SO2, 1395 cm−1 for CO2, and 2150 cm−1 for CO), and the corresponding simultaneous detection limit can be obtained as: 5.96 ppm $\cdot $ bar for SOF2, 3.76 ppm $\cdot $ bar for SO2F2, 1.89 ppm $\cdot $ bar for COS, 5.82 ppm $\cdot $ bar for CF4, 2.23 ppm $\cdot $ bar for SO2, 6.20 ppm $\cdot $ bar for CO2, and 14.82 ppm $\cdot $ bar for CO with the laser power of 200 mW and the exposure time of 60 s. Finally, the dynamic analysis of SF6 decomposition gases produced by metal protrusion partial discharge (PD) defect model is also achieved. The designed FERS sensing system fully demonstrates its ability to simultaneously and dynamically analyze the SF6 decomposition products, which lays the foundation for more accurate and earlier diagnosis of SF6 GIPE failures.