Experimental studies on the power- frequency breakdown voltage of CF3I/N-2/CO2 gas mixture

摘要

Trifluoroiodomethane is a promising alternative to SF6 because of its good insulation properties and much less serious greenhouse effect than SF6. Previous studies have shown that the insulation performance of CF3I mixed with CO2 or N-2 can equal that of SF6. This study explored the frequency breakdown characteristics of CF3I and SF6 mixed with two buffer gases. The effects of air pressure and field strength were analyzed. The fixed mixing ratio of CF3I and SF6 was 30 in the experiment. The breakdown experiment was conducted by changing the mixing ratio of CO2 and N-2. Results showed that the CO2/N-2 mixture ratio did not exert a synergetic effect, and the CF3I/CO2 breakdown performance was better than that of CF3I/N-2 in the quasi-uniform and highly non-uniform electric fields. CO2 possibly provided the C atoms for the entire system to maintain a certain balance in C, and this balance inhibited the decomposition of CF3I. The breakdown performance of SF6/N-2 was good in quasi-uniform field, whereas that of SF6/CO2 was good in the highly non-uniform field. Published by AIP Publishing.