Online dynamic detection of multiple SF6 discharge decomposition products can more comprehensively evaluate the operating status and improve the operational reliability of SF6 gas insulated equipment. This article proposes the full-power optical feedback frequency locking (FPOFFL) technology and designs the FPOFFL cavity-enhanced Raman spectroscopy gas sensing system for online dynamic measurement of multiple SF6 decomposition gases. Compared with traditional optical feedback frequency locking technology

the proposed FPOFFL technology can further improve the Raman spectrum detection performance by 2.78 times. Combined with standard mixed gas samples

the Raman peak positions of the system for qualitative and quantitative analysis of multiple SF6 discharge decomposition products are determined

along with the μL/L levels limits of detection (SOF2: 4.70 μL/L

SO2F2: 3.73 μL/L

COS: 1.91 μL/L

CF4: 7.07 μL/L

SO2: 2.31 μL/L

CO2: 8.59 μL/L

CO: 17.64 μL/L). Finally

the sensing system conducts a 7-day online dynamic measurement of the partial discharge decomposition products of the true model of SF6 gas insulation equipment at a 1-hour measurement interval. The measurement results demonstrats a relative error of no more than ±5% compared to gas chromatography

which fully validates the system's online dynamic detection capability for SF6 discharge decomposition products.