평등/불평등 전계에서의 SF_(6)혼합가스의 절연특성 연구

Abstract

SF_(6) gas is widely used as a plausible insulation media employed for the Gas insulated power components ascribed to its excellent insulation properties. However, the price is considerably high and global warming could be brought when it is leaked from the apparatus. Moreover, its liquefaction at low temperature causes the decrease of insulation properties. Recently many a research work have been investigated to find any possible substitutes with better insulation properties. But several materials recommended by this time have not yet been employed for the commercial purpose. In order to propose an alternative choice, seven different gases such as SF_(6), Dry air, N₂, CO₂, SF_(6) mixture with Dry air, N₂, CO₂ are chosen for the experimental investigation that has been carried out for the followings: breakdown strength and partial discharge patterns from the vital defects introducible into the power component. The dielectric strength of SF_(6)/Dry SF_(6)/N₂, SF_(6)/CO₂, SF_(6) mixtures reaches to nearly 83%~84%, 85%~90%, 85~90% of pure SF_(6) when the portion of SF_(6) is 20%. The optimum mixture portion of SF_(6) could be proposed to be 20% for the gas insulated power components. The nature of the defects could be identified based on the related PD patterns. SF_(6) mixture gases shows the similar PD pattern to pure SF_(6) and its PD level is almost close to that of pure SF_(6)