Inception corona discharge voltages in SF6-N2 gas mixtures at high gas pressure

Abstract

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 currentvoltage characteristics under high pressures and with highly inhomogeneous fields. The results show that the onset voltages increase with the increase of the gas pressure and are relatively higher for positive polarity. It can also be seen that for low concentrations of SF6 in the mixture the increase of the onset voltages is substantial, followed by a slow increase for elevated concentration of SF6 in the mixture, which, can be an advantage for the substitution of SF6.