Regular Article

Ignition and advancement of surface discharges at atmospheric air under positive lightning impulse voltage depending on perpendicular electric stress and solid dielectrics: modelling of the propagating phenomenology

¹ Sicame Group S.A., Laboratoires LABEP, Avenue Basile Lachaud B.P. 1, 19230 Arnac-Pompadour, France
² University of Lyon I, École Centrale de Lyon, Laboratoire Ampère CNRS UMR 5005, 36 Avenue Guy de Collongue, 69130 Ecully, France

^* e-mail: adnane.douar@outlook.com

Received: 23 February 2018
Received in final form: 1 May 2018
Accepted: 25 May 2018
Published online: 15 August 2018

Abstract

In many high voltage equipment, partial discharges are regarded as one of the most widespread pathology whose ignition conditions and effects are studied by scientists and manufacturers to avoid major failures. Actually, those electrical gaseous phenomena generally occur under several constraints such as the electrostatic field level, the nature of insulating surface being polluted or not, and switching or lightning transients. The present paper discusses physical mechanisms related to the creeping discharges propagation growing over insulators subjected to perpendicular electric field and positive lightning impulse voltage. More precisely, the developed discussion attempts to answer some observations especially noticed for main discharges feature namely (i) the discharges morphology, (ii) their velocity and (iii) the space charges effects on electric field computation. Several factors like (i) the influence of the type of a material’s interface, its electric conductivity, permittivity and discharges mobility, (ii) the relationship between the applied electrostatic field, the space charges, the velocity, the propelling pressure and discharges temperature are among numerous parameters that have been addressed in this study which discusses lightning impulse transients phenomena.