Microparticle Insulation Mixture for Sulfur Hexaflouride (SF6) Replacement or Reduction

SF6 is widely used as an insulating gaseous medium in electric power industry, high voltage research and military applications because of its superior dielectric and chemical properties. However, SF6 is one of the six greenhouse gases regulated under the Kyoto Protocol due to its high global warming potential (GWP) and its long lifetime in the environment, its release to the atmosphere needs to be limited. Intensive research on the electrical insulating properties of compressed gases and gas mixtures, including N2/SF6 gas mixtures, has been carried out for many years and is stimulated by the desire to find alternatives to SF6 gas. But to date no equivalent alternative gas has been identified because of the many basic and practical requirements that a gas must satisfy and the many studies and tests that must be performed to allow confident use. In this project, we propose one type of insulation mixture, comprising micro-particles of a solid insulator and SF6 gas, to reduce the quantity of pure SF6 gas in high voltage applications. Initial experiments will adopt quartz powder mixed with SF6. Experimental data and analysis indicate that the mixture is promising for use in high voltage applications.