Effect of O₂ on AC Partial Discharge and Decomposition Behavior of C₄F₇N/CO₂/O₂ Gas Mixture

Generation Characteristics of Solid Byproducts of the C4F7N–CO2–O2 Gas Mixture under PD Fault

“…Previous research indicates that if the C 4 F 7 N−CO 2 gas mixture is required to meet the minimum operating temperature of −25 °C within the pressure range of 0.1−0.2 MPa, the content of C 4 F 7 N in the mixture should not exceed 18%. 20 In addition, research shows that the generation of most of the decomposition products of the C 4 F 7 N−CO 2 − O 2 gas mixture is the lowest at 4% O 2 after the 96 h PD decomposition test, 21 steel gas chamber is collected every 12 h for composition analysis. Considering that the gas composition in the gas chamber tends to be stable at the end of the test, this paper only analyzes the gas composition of 96 h. Figure 2 shows the gas chromatogram of the 15% C 4 F 7 N−85% CO 2 gas mixture after the 96 h PD test.…”

“…Previous research indicates that if the C 4 F 7 N–CO 2 gas mixture is required to meet the minimum operating temperature of −25 °C within the pressure range of 0.1–0.2 MPa, the content of C 4 F 7 N in the mixture should not exceed 18%. 20 In addition, research shows that the generation of most of the decomposition products of the C 4 F 7 N–CO 2 –O 2 gas mixture is the lowest at 4% O 2 after the 96 h PD decomposition test, 21 so this paper studies the generation characteristics of the solid decomposition products of the C 4 F 7 N–CO 2 –O 2 gas mixture containing 15% C 4 F 7 N at 0.14 MPa under different O 2 contents (0 and 4%), and the discharge time of each group of tests is 96 h. The gas and solid byproducts of the C 4 F 7 N–CO 2 –O 2 gas mixture at different O 2 contents were analyzed and tested based on GC-MS, SEM, EDS, and XPS, and the gas–solid compatibility of the mixture and metal conductor at different O 2 contents was evaluated based on the relevant results.…”

Ag Modified SnS2 Monolayer as a Potential Sensing Material for C4F7N Decompositions: A Density Functional Theory Study

“…In the case of C 4 F 7 N based GIE, partial discharges CAN result in the generation of gases such as C 3 F 6 , C 2 F 6 , C 3 F 8 , CF 4 , and CO. Notably, the concentration of CF4 demonstrates a strong linear correlation with both the intensity and duration of the discharge . In scenarios of partial overheating, the primary decomposition products of the C 4 F 7 N mixed gas include C 3 F 6 , CO, CF 4 , C 2 F 6 , CF 3 CN, COF 2 , and C 2 N 2 .…”

Arc decomposition behavior of C 4 F 7 N/Air gas mixture and biosafety evaluation of its by‐products

“…The GWP of a C 4 F 7 N/CO 2 gas mixture with 4% and 10% C 4 F 7 N is 327 and 690, respectively, which is only 2%-3% that of SF 6 [8]. Besides, the dielectric strength of pure C 4 F 7 N gas is twice that of SF 6 and the insulation performance of C 4 F 7 N/CO 2 with 18%-20% C 4 F 7 N is equivalent to that of SF 6 [9]. Comprehensive performance evaluations of C 4 F 7 N on insulation performance [6][7][8][9], decomposition characteristics [10,11] and material compatibility [12] have been conducted, and have demonstrated that C 4 F 7 N has the application potential for both medium-voltage and high-voltage GIE.…”

“…Besides, the dielectric strength of pure C 4 F 7 N gas is twice that of SF 6 and the insulation performance of C 4 F 7 N/CO 2 with 18%-20% C 4 F 7 N is equivalent to that of SF 6 [9]. Comprehensive performance evaluations of C 4 F 7 N on insulation performance [6][7][8][9], decomposition characteristics [10,11] and material compatibility [12] have been conducted, and have demonstrated that C 4 F 7 N has the application potential for both medium-voltage and high-voltage GIE. For example, General Electric successfully developed a 245 kV current transformer and 145 kV gas-insulated switchgear with C 4 F 7 N gas as the insulation medium and put them into trial operation [13].…”