Influence of oxygen on dielectric and decomposition properties of C4F7N-N2-O2 mixture

Li, Yang; Zhang, Xiaoxing; Chen, Qi; Zhang, Ji; Li, Yalong; Xiao, Song; Tang, Ju

doi:10.1109/tdei.2019.007996

Cited by 38 publications

(28 citation statements)

References 13 publications

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“…Once at rest, unlike SF 6 , the decomposition products do not recombine to the original chemical arrangement. They react with contaminants such as water [8], oxygen [9], the buffer gas, metal electrodes [10][11][12], solid dielectrics [13], and/or adsorbents [14] to form other chemically stable decomposition by-products. High water content causes an increase in dielectric loss, accelerates the decomposition of Novec TM 4710 in the presence of electrical discharge or corona, and accelerates corrosion of the materials when in contact with decomposition products.…”

Section: Introductionmentioning

confidence: 99%

AC Volume Breakdown and Surface Flashover of a 4% NovecTM 4710/96% CO2 Gas Mixture Compared to CO2 in Highly Nonhomogeneous Fields

et al. 2020

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AC pre-discharge currents, breakdown, and flashover voltage measurements are reported in a 10 mm needle-plane arrangement in a 4% NovecTM 4710/96% CO2 gas mixture and compared with CO2 for pressures up to 8.8 bar abs. Flashover measurements were performed on different solid dielectrics (Al2O3_filled epoxy resins, PTFE (Polytetrafluoroethylene) and PE (polyethylene)) for different roughness surface finishes. The effect of fixed conducting needles at various positions on electrical strength is reported. A strong nonlinear behaviour as function of gas pressure was observed for all the studied parameters (gas, needle position, solid insulator, insulator roughness). The non-linear behaviour is attributed to the inception and quenching of glow corona, in the interval between inception and breakdown or flashover voltages. It is found that a 4% concentration of NovecTM 4710 in CO2 has a breakdown/flashover voltage ≈ 1.14 higher than CO2. The glow corona-induced stabilization effect is seen for pressures between 2 and 5 bar abs for all the studied parameters. The peak flashover voltage and its associated pressure of the different insulators are strongly dependent on surface roughness. At 8.8 bar abs, the flashover voltage level obtained with various materials was ordered as follows: PTFE > PE-UHMW > Epoxy > HDPE(High-density polyethylene).

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Section: Introductionmentioning

confidence: 99%

AC Volume Breakdown and Surface Flashover of a 4% NovecTM 4710/96% CO2 Gas Mixture Compared to CO2 in Highly Nonhomogeneous Fields

et al. 2020

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“…Adding O 2 to C 3 F 7 CN/N 2 mixtures will promote the decomposition of C 3 F 7 CN, and produce oxygen-containing decomposition products, including CO 2 and COF 2 [44]. Considering the influence of O 2 on the insulation performance of the C 3 F 7 CN/N 2 gas mixture, C 3 F 7 CN/N 2 added with 4-6% volume fraction O 2 shows certain improvement [45] whereas C 3 F 7 CN/CO 2 /O 2 added with 2-6% volume fraction of O 2 has a certain inhibition effect on the production of discharge by-products [44]. Fig.…”

Section: 11mentioning

confidence: 99%

“…C 3 F 7 CN/N 2 mixtures may have black matter precipitation on the electrode surface after multiple discharge and breakdown, which has been confirmed in the several researches above. However, researchers found that adding a small amount of O 2 can inhibit the precipitation of solid matter such as carbon [44, 45]. Adding O 2 to C 3 F 7 CN/N 2 mixtures will promote the decomposition of C 3 F 7 CN, and produce oxygen‐containing decomposition products, including CO 2 and COF 2 [44].…”

Section: Gas Decomposition Properties and Compatibility With Solid mentioning

confidence: 99%

Feasibility of C ₃ F ₇ CN/CO ₂ gas mixtures in high‐voltage DC GIL: a review on recent advances

Chen

Wang

et al. 2020

High Voltage

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With the rise of renewable energy resources, especially offshore wind power plant, the DC transmission concept has attracted more and more attention. The selection of eco‐friendly insulating gas, as most critical insulating part of gas‐insulated equipment is top priority for developing highly reliable system. Moreover, it is acknowledged that eco‐friendly C3F7CN/CO2 gas mixtures have become a potential alternative to SF6 gas due to its excellent performance. This study reviews the basic physical properties of C3F7CN gas/gas mixtures and insulation properties including the gas gap breakdown and surface flashover performance at DC, as well as lightning impulse voltage. Investigation about the gas stability is presented, including the compatibility of gas with solid materials in gas‐insulated transmission line (GIL), and the decomposition characteristics under long‐term electrical and thermal stresses. The important progress on the charge accumulation characteristics of gas–solid interface in the novel gas environment under DC voltage stress is analysed. Finally, the key issues that need to be paid attention to and further followed through regarding the application of this novel gas in GIL are summarised and put forward. This study hopefully can provide a complete reference for the development of eco‐friendly DC gas insulation equipment with C3F7CN/CO2 gas mixtures.

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“…HFO-1234zeE will precipitate carbon deposits on the solid after a flashover and have a risk of flammability [3,18]. C 4 F 7 N demonstrates excellent insulation performance, but its toxicity is relatively high, and the risks of large-scale engineering application still require further study [19][20][21]. The application prospect of fluoroketones in electrical equipment has been widely optimistic in the past few years, and related research has mainly focused on C5-PFK and C6-PFK gas mixtures.…”

Section: Introductionmentioning

confidence: 99%

Compatibility between C6F12O–N2 Gas Mixture and Metal Used in Medium-Voltage Switchgears

et al. 2019

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C6F12O has been introduced as the potential alternative gas to SF6 because of its excellent insulation properties and great eco-friendly performance. Considering that C6F12O may react with the internal materials of switchgears in practical applications, its compatibility with metal materials must be tested to evaluate its long-term application possibilities. In this work, the compatibility of C6F12O–N2 gas mixtures with aluminum and copper was tested at different temperatures by setting up a heat-aging reaction platform between the gas and each metal. The metal surface morphology and gas composition before and after the reaction were compared and analyzed. The results show that the surface color of the copper sheet changed considerably, and the corrosion degree of the surface deepened with the increase of temperature. The decomposition of C6F12O was also promoted. In contrast, aluminum did not react severely with the gas mixture. The compatibility of the gas mixture with aluminum was generally better than that of copper.

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Influence of oxygen on dielectric and decomposition properties of C₄F₇N-N₂-O₂ mixture

Cited by 38 publications

References 13 publications

AC Volume Breakdown and Surface Flashover of a 4% NovecTM 4710/96% CO2 Gas Mixture Compared to CO2 in Highly Nonhomogeneous Fields

AC Volume Breakdown and Surface Flashover of a 4% NovecTM 4710/96% CO2 Gas Mixture Compared to CO2 in Highly Nonhomogeneous Fields

Feasibility of C ₃ F ₇ CN/CO ₂ gas mixtures in high‐voltage DC GIL: a review on recent advances

Compatibility between C6F12O–N2 Gas Mixture and Metal Used in Medium-Voltage Switchgears

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Influence of oxygen on dielectric and decomposition properties of C4F7N-N2-O2 mixture

Cited by 38 publications

References 13 publications

AC Volume Breakdown and Surface Flashover of a 4% NovecTM 4710/96% CO2 Gas Mixture Compared to CO2 in Highly Nonhomogeneous Fields

AC Volume Breakdown and Surface Flashover of a 4% NovecTM 4710/96% CO2 Gas Mixture Compared to CO2 in Highly Nonhomogeneous Fields

Feasibility of C 3 F 7 CN/CO 2 gas mixtures in high‐voltage DC GIL: a review on recent advances

Compatibility between C6F12O–N2 Gas Mixture and Metal Used in Medium-Voltage Switchgears

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Influence of oxygen on dielectric and decomposition properties of C₄F₇N-N₂-O₂ mixture

Feasibility of C ₃ F ₇ CN/CO ₂ gas mixtures in high‐voltage DC GIL: a review on recent advances