Review of research progress in SF₆ substitute gases

SF₆ gas is widely used in electric power apparatus as an insulation and arc-quenching medium. However, the application of SF₆ gas faces two serious problems, including the heavy global warming effect and high liquefaction temperature. To deal with this issue, lots of research institutes have carried out many experiments and theoretical investigations in recent decades, from which a lot of valuable results have been obtained. We review the recent research progress in SF₆ substitute gases, and emphatically introduce several gases and gas mixtures concerned recently, including single common gas, SF₆ mixture, and new enviroment-friendly gas. Based on the research progress, the main problems faced are analyzed, and the issues needed to study urgently are proposed, such as gas-solid composite insulation technology, decomposition, and composition characteristics, heat dispersion performance, composition monitor, and gas filling strategy. Some valuable references are expected to provide for exploration on SF₆ substitute gases and development of new enviroment-friendly electric power devices.