Characterization of partial discharge decomposition of SF6/N2 gas mixture with different microwater contents

The SF6/N-2 gas mixture as a preliminary alternative to SF6 is used in the power industry gas insulation medium. At present, the application of the 30% SF6/70% N-2 gas mixture has made some progress, but the influence law of microwater content on its discharge decomposition characteristics is still unclear. In this paper, we simulate the defects of metal protrusions in the equipment through needle-plate electrodes, carry out SF6/N-2 96hPD and its decomposition characteristic test under different microwater contents, and find that the increase of the microwater content in the SF6/N-2 gas mixture will exacerbate the phenomenon of PD, resulting in the enhancement of the average discharge, and under the action of prolonged PD, more characteristic decomposition products will be generated, of which the SOF2 content is the highest, which can be as one of the characteristic components for fault severity judgment. This study provides a certain reference for the specific requirements of the microwater content of the SF6/N-2 gas mixture in power equipment.