Creeping discharges features propagating in air at atmospheric pressure on various materials under positive lightning impulse voltage – part 2: modelling and computation of discharges’ parameters

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

“…Previous investigations demonstrated that discharges extensions as well as their brightness are well correlated with the voltage enhancement and the type of used barrier incorporated between electrodes [21]. It has also been shown that both discharges' brightness and thickness depend on the crest value applied to the material and on the chosen polarity (being positive or negative).…”

“…The tested materials belong to three distinguishable polymeric families [20,21]: (1) thermoplastics (namely polyamide 6 filled with 50 wt.% of glass fibers (noticed as PA6/50, Fig. 2a) and polyamide 66 filled with 50 wt.% of glass fibers (noticed as PA66/50, Fig.…”

“…In this paper, effects of lightning impulse voltage under positive polarity on the propagation of creeping discharges over various solid dielectrics are analyzed. As described in previous publications [20,21], the main concerns were about (i) de-noising some data such as current, voltage and captured images at first [20], and then moving to (ii) modeling and calculation of discharges parameters using different mathematical formulations for more accuracy [21]. In this survey study, an attempt to explain various physical phenomena, observation and results obtained during experiments (namely the discharges morphology, the velocity and then the space charges influence) is presented as an overview of the discharges growth mechanism in air, depending on the used polymeric interface, and to identify the mutual interaction that exists between discharges and assessed plastics.…”

Surface Discharges and Flashover Modelling of Solid Insulators in Gases

“…Fundamental studies have been conducted to understand the inception and (insulator shape, electrodes form…), etc. Fundamental studies have been conducted to understand the inception and propagation of creeping discharges in various gases [7][8][9][10][11][12][13][14]. It appears from the reported results that the phenomena start with corona discharges that evolves into ramified streamers.…”

“…Modelling and calculation of flashover voltage is not an easy task because of the interaction of different parameters, such as gas pressure and its chemical constitution, physicochemical properties of the solid insulator, nature and distribution of the surface charges, etc. Different models have been proposed in order to compute the inception voltage of creeping discharges and flashover voltage of insulator in air at atmospheric pressure [2,3,13,14]. Hayakawa et al [7] analysed the mechanism of impulse creeping discharge propagation on charged PMMA (poly-methyl methacrylate) surface.…”