Research on insulation characteristics and decomposition products of c-C4F8/N2 mixtures in slightly non-uniform electric field

High liquefaction temperature and greenhouse effect are two major problems of SF₆. To find alternative gas of SF₆ becomes an urgency in power industry. In this paper, the insulation characteristics of c-C₄F₈/N₂ are studied. The AC breakdown voltage in slightly non-uniform electric field with different air pressure and mix ratio is measured. The results show that breakdown voltage increases with the increase of the pressure and the proportion of c-C₄F₈ within the range of experimental conditions and c-C₄F₈/N₂ has considerable insulation properties as compared with SF₆. In addition, the mixtures gas after breakdown is detected. C₂F₄, a new decomposition product, is found. Results in this paper provide a reference for the practical application of c-C4F8/N₂ mixturess in power industry.