In an effort to respond to the recent concerns over the possible impact of SF6 on global warming, we have searched for an SF6 substitute gas that could be used in high voltage equipment instead of pure SF6, with minimal changes in practice, operation, and ratings of the existing pure SF 6-insulated apparatus. Of the many unitary, binary, and tertiary gases/mixtures that have been tested to date, SF6-N2 mixtures seem to be the most promising and most thoroughly characterized gaseous dielectric media besides pure SF6. Based upon research conducted world-wide over the last few decades, it appears that the optimum composition of an SF6-N2 mixture for use as a gaseous dielectric in place of pure SF6 for both high voltage insulation [such as in gas-insulated transmission lines and gas-insulated transformers] and possibly also for arc and current interruption purposes may be in the range 40% to 50% SF6 in N2 (by volume). Most of the existing data support the use of such mixtures for gas-insulated transmission lines and gas-insulated transformers, but their use for circuit breakers is still in question requiring further exploration.
Proceedings Title: Proc., Intl. Symp. on Gaseous Dielectrics
Conference Dates: June 2-5, 1998
Conference Location: Virginia Beach, VA
Pub Type: Conferences
all-purpose gaseous dielectrics, dielectric gas mixtures, substitutes, sulfur hexafluoride