Onset corona discharge voltages in SF6-N2 gas mixtures at higher gas pressures

The use of sulphur hexafluoride (SF₆) has led to increased concentration of this gas in the atmosphere. The purpose of this work is to investigate the behaviour of SF₆-N₂ mixtures that can be considered as a potential substitute of pure SF₆. The onset corona discharge voltages have been determined from the measurements of the current-voltage characteristics under high pressures and with highly inhomogeneous fields. The results show that the onset voltages increase with the increase of the gas pressure. It can also be seen that for low concentrations of SF₆ in the mixture the increase of the onset voltages is substantial, which, can be an advantage for the substitution of SF₆.