Monte Carlo Simulation Of C-C₄ F₈ And CHF₃ Mixed Gas Discharge Characteristics

SF₆ is widely used in power system and electrical equipment as an excellent insulation and arc extinguishing medium. In December 1997, SF₆ was indentified as one of six greenhouse gases needed to be reduced and it is therefore an urgent case to reduce and control the release of greenhouse gas. So it is imperative to seek the substitution gas of SF₆.The paper used the Monte Carlo simulation method to describe the development process of electron collision in gas discharging. The paper lifted the simulation speed and improved Monte Carlo simulation method on the basis of traditional air-collision method.The paper also built Monte Carlo simulation model of single gas and analyzed ionization cross section, attached to the collision cross sections, vibrational excitation collision cross sections, electron excitation collision cross section, the neutral collision cross section of c-C₄F₈ and CHF₃ and using Monte Carlo simulation to determine the parameters of gas collision cross sections and comparing with the test data. Finally the paper identified a set of c-C₄F₈ and CHF₃ gas collision cross sections that is better than the published data.The paper made Monte Carlo simulation to CHF₃/C₄F₈ binary mixed gas. The improved Monte Carlo simulation method was used to determine the type of the electron collision of mixed gas and got a better data of the critical breakdown field strength compared to the traditional method.The paper analyzed the feasibility of applying CHF₃/C₄F₈ mixed gas to be the replacement of SF₆ insulation gas. On the dielectric strength, the dielectric strength of CHF₃/C₄F₈ mixed gas is betten than that of SF₆/CF4 mixed gas, weaker than that of C₄F₈/N2 mixed gas. In regards of greenhouse effect, GWP of CHF₃/C₄F₈ mixed gas is lower than SF₆ and SF₆/CF4 mixed gas. Above all, CHF₃/C₄F₈ mixed gas mixture has the possibility of becoming the replacement of SF₆ insulation.