Abstract：As the greenhouse effect of SF6 gas, it has become a common view that less or no SF6 gas would be used in future, and many studies have been carried out recently on gas mixtures composed of a small amount of electronegative gas and a buffer gas. This paper measured the partial discharge initial voltages and breakdown voltage of CF3I-CO2 mixtures under needle-plate electrode with 50Hz ac high voltage and compared that with SF6-CO2 mixtures, and analyzed the effect of mixing ratios, gas pressures on the partial discharge initial voltage of CF3I-CO2 mixtures. The experimental results show that the breakdown voltage of pure CF3I gas is about 1.2 times of that of SF6 gas in 0.1MPa; the partial discharge initial voltages of CF3I-CO2 mixtures are about 0.9～1.1 times of that of SF6-CO2 mixtures, and the favorable synergistic effect is observed between CF3I gas and CO2 gas, the synergistic factor is about 0.53; the partial discharge initial voltages of CF3I-CO2(30%-70%) mixtures are about 0.74 times of that of SF6 gas. Consequently, from the point of partial discharge performance, CF3I-CO2 (30%-70%) mixtures can be considered as SF6 substitute used in gas-insulated power apparatus.
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2013, Vol. 28 
