Interruption capability of CF/sub 3/I Gas as a substitution candidate for SF/sub 6/ gas

Abstract

We studied the interruption performance of CF 3 I gas because its environmental effect is smaller than that of SF 6 gas with a model arc-extinguishing chamber. First, we measured the arc time constant and arc power loss coefficient using Mayr's equation. Comparing CF 3 I with other gases, the arc time constants are SF 6 < CF 3 I < CO 2 < H 2 < Air < N 2 . The arc power loss coefficient is H 2 > SF 6 > CO 2 > Air > N 2 > CF 3 I. Next, we evaluated the Short Line Fault (SLF) interruption capability by measuring the di/dtdv/dt characteristic. Consequently, the SLF interruption performance of pure CF 3 I was about 0.9 times that of SF 6 . However, CF 3 I application to gas insulated switchgear (GIS) and gas circuit breakers (GCB) is difficult because the liquefying temperature of the gas is high. Therefore, we adopted a countermeasure to obtain a lower liquefying temperature mixing CF 3 I with CO 2 . The result showed that the SLF interruption performance of the mixture approximated that of pure CF 3 I when the ratio of CF 3 I exceeds 20%.Index Terms -CF 3 I, short line fault (SLF), substitute gas for SF 6 .

Thermal Recovery Characteristics of a CO2Mixture Gas Circuit Breaker

“…It is well known that the dielectric and interruption capabilities of CO 2 are only 20~30% of those of SF 6 [13]. The ablation of the solid insulation material affects the pressure-rise in the thermal expansion chamber [4].…”

Solid by-products of a CF3I–CO2insulating gas mixtures on electrodes after lightning impulse breakdown

“…One alternative insulation gas that shows promising insulation properties to replace SF 6 is Trifluoroiodomethane (CF 3 I) and its mixtures [3]. An important characteristic of CF 3 I includes its ability to rapidly decompose in solar light which results in a GWP of less than 5 [4]. CF 3 I also has an extremely short atmospheric lifetime of less than 2 days [4].…”

Analysis of Insulating Characteristics of Cl2-He Mixture Gases in Gas Discharges

“…Moreover, this gas and its mixtures have been widely used in plasma etching of semiconductors, metals, and gate stacks with high-κ dielectrics and low-κ dielectric films [2][3][4][5][6].…”