Breakdown Characteristics of N2O Gas Mixtures for Quasiuniform Electric Field under Lightning Impulse Voltage

From the viewpoint of mitigating global warming by SF6gas, this paper discusses breakdown (BD) characteristics of different electronegative gas mixtures with N2O gas as SF6gas substitutes for quasi-uniform electric field under lightning impulse voltage applications. Experimental results revealed the positive synergism in breakdown strength of binary N2O / CO2and ternary N2O / CO2/ O2gas mixtures, respectively. Furthermore, N2gas as a retardant gas was also mixed with the electronegative gas mixtures in order to reduce the electron energy into the effective levels of electron attachment ability by the electronegative gas mixtures. As the result, ternary N2O / CO2/ N2and quaternary N2O / CO2/ O2/ N2gas mixtures could exhibit the significant synergistic effect in breakdown strength. The optimum mixture rate of quaternary N2O / CO2/ O2/ N2gas mixtures was consistent with that estimated by assuming the independent contribution of component gases to the improvement of impulse BD characteristics.