deng xianqin / State Grid Shanghai Electric Power Research Institute
High liquefaction temperature and greenhouse effect are two major problems of SF6. To find alternative gas of SF6 becomes an urgent 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 compared with SF6. In addition, the mixture 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 mixtures in power industry.