Surface Discharges over Insulators of various materials in presence of SF6, CO2, N2 and SF6-CO2 and SF6-N2 Mixtures under DC voltage

Fares Sadaoui (1) , Abderrahmane Beroual (1)

1 AMPERE - Ampère

This paper is aimed at the experimental characterization of discharges propagating at solid/gas interfaces under DC voltage using a point-plane electrode arrangement. Specifically, we analyze the morphology of creeping discharges and their final (i.e., stopping or maximum extension) length against the type of insulator and its thickness, the amplitude of the applied voltage, the type of gas (mixture) and its pressure. The insulators we investigate are Bakelite and glass; and the considered gases are N2, SF6, CO2 and mixtures SF6 - N2 and SF6 - CO2. The obtained results show that the discharges can be radial or not depending on the type of interfaces. However, as we observed for AC and lightning impulse voltages, the final length Lf increases quasi-linearly with the voltage; it decreases when the gas pressure increase. Lf is shorter in SF6 than in CO2 or N2; and the increase of SF6 content in the investigated mixtures leads to a significant decrease of Lf.

Mots clés: Glass; Insulators; Lightning; Solids; Electrodes; Discharges (electric); Sulfur hexafluoride

Domaines: Energie électrique

Fares Sadaoui, Abderrahmane Beroual. Surface Discharges over Insulators of various materials in presence of SF6, CO2, N2 and SF6-CO2 and SF6-N2 Mixtures under DC voltage. CEIDP, Oct 2013, Shenzhen, China. pp.472 - 475, ⟨10.1109/CEIDP.2013.6748170⟩. ⟨hal-00921847⟩