Eco-friendly Gases

Sulfur hexafluoride (SF6) is a nontoxic, nonflammable and chemically stable gas that is widely used as an arc quenching medium in medium-voltage (MV) and high-voltage (HV) circuit breakers and as an insulating medium in gas-insulated substations (GIS) and gas-insulated lines (GIL). However, SF6 has been designated as one of the six greenhouse gases by the Kyoto Protocol because the global warming potential (GWP) of SF6 is nearly 24000 times higher than that of CO2 over a 100 year interval. Additionally, SF6 decomposes into lower fluorides of sulphur which in turn react with electrodes or gas impurities to form many toxic products, such as sulphur dioxide, hydrofluoric acid and metal fluoride compounds, which are hazardous to maintenance personnel. Finding suitable substitutes to SF6 is therefore an urgent task.

Electron Energy Distribution Function (EEDF)

EEDF

EEDF of different SF6-CO2 mixtures at a reduced electric field strength E/N of 200Td, a temperature of 2000K and a pressure of 0.1MPa.

Ionization Coefficients ($\alpha/N$)

Ionization Coefficients

$\alpha/N$ of different SF6-CO2 mixtures as a function of $E/N$ at a temperature of 2000K and a pressure of 0.1MPa.

Electron Attachment Coefficients ($\eta/N$)

Electron Attachment Coefficients

$\eta/N$ of different SF6-CO2 mixtures as a function of $E/N$ at a temperature of 2000K and a pressure of 0.1MPa.

Critical Electric Field Strength ($(E/N)_{cr}$)

Critical Electric Field Strength

$(E/N)_{cr}$ of different SF6-CO2 mixtures as a function of temperature at 0.1MPa

Publications

. Effects of Buffer Gases on Plasma Properties and Arc Decaying Characteristics of C4F7N-N2 and C4F7N-CO2 Arc Plasmas. Plasma Chemistry and Plasma Processing, 2019.

PDF Project

. Evaluation of Arc Quenching Ability for a Gas by Combining 1-D Hydrokinetic Modeling and Boltzmann Equation Analysis. IEEE Transactions on Plasma Science, 2019.

PDF Project

. Effects of copper vapour on thermophysical properties of CO2-N2 plasma. The European Physical Journal D, 2016.

PDF Project Project

. Effects of Copper on Thermophysical Properties and Net Emission Coefficients of CO2-N2 Mixtures in High-Voltage Circuit Breakers. The 14th High-Tech Plasma Processes Conference (HTPP 14) (Munich, Germany), 2016.

Project Project

. Investigation of dielectric properties of cold C3F8 mixtures and hot C3F8 gas as Substitutes for SF6. The European Physical Journal D, 2015.

PDF Project

. Influence of copper contamination on dielectric breakdown properties of high-temperature SF6 gas based on Boltzmann equation analysis. 3rd International Conference on Electric Power Equipment - Switching Technology (Busan, Korea), 2015.

PDF Project

. Dielectric breakdown properties of hot SF6 gas contaminated by copper at temperatures of 300–3500 K. Journal of Physics D: Applied Physics, 2015.

PDF Project

. Dielectric breakdown properties of hot SF6-CO2 mixtures at temperatures of 300–3500 K and pressures of 0.01–1.0 MPa. Physics of Plasmass, 2014.

PDF Project

. Prediction of critical dielectric strength of hot CF4 gas in the temperature range of 300-3500 K. IEEE Transactions on Dielectrics and Electrical Insulation, 2014.

PDF Project