Abstract:

In order to reduce greenhouse gas emissions,the research on environment-friendly SF₆ alternative gas should be carried out,and the timely evaluation and application should be promoted.At present,in terms of arc extinguishing,vacuum interrupter is widely used as the main breaking unit to replace SF₆ arc extinguishing medium for 40.5 kV and below voltage level switchgear.In terms of insulation,the great progress has been made in the research of using environmental protection gas instead of SF₆ as the insulation medium.The research focuses are mainly on dry air,N₂,C4-PFN (fluorinated nitriles) gas and its mixture,perfluorones (C_nF_2nO) gas and its mixture,etc.Through the analysis and comparison of their insulation,temperature rise,physical and chemical characteristics,their advantages and disadvantages and application status are summarized,and a certain gas or mixed gas is determined as an ideal alternative gas for SF₆ under a specific voltage level to carry out in-depth application research.

Key words: gas insulated switchgear(GIS), SF₆ alternative gas, insulation characteristics, temperature rise