On the transition from stable positive glow corona to streamers

Abstract

A two-dimensional numerical simulation of the transition from stable positive glow corona to streamers in coaxial cylindrical configuration is presented. The hydrodynamic model with several convection-dominated continuity equations together with Poisson equation are solved with consideration of the ionization layer. The transition from a stable positive glow corona produced under a DC voltage to streamers is investigated under a sudden change of the applied voltage. The critical rate of rise of voltage required for the transition from positive glow to streamer corona is evaluated with a voltage ramp. By introducing either physical or numerical instabilities into the model, streamers with filamentary structures are observed, which produce a sudden increase of the discharge current by more than two orders of magnitude. It is also found that the surface electric field of the corona-generating conductor deviates from the onset electric field, casting doubts about the validity of Kaptzov's approximation to evaluate the transition from stable glow to streamers.

The different stages of PRPD pattern for positive point to plane corona driven by a DC voltage containing ripple

“…The reduced measured discharge activity can be explained in the same way. In general the discharge frequency of burst pulses is proportional to the positive ion mobility [17,18] and therefore to the height of the applied voltage. This could also be observed in this study.…”

Improvement of Corona Discharge Model and Its Application on Simulating Corona Discharge in the Presence of Wind

“…First, because we are interested in the timedependent production and evolution of corona ions in larger space domain of several hundreds of meters, the thickness of the ionization layer within several of millimeters near the corona discharge surface is ignored. According to Kaptzov's assumption, the local electric field near a corona-producing surface is equal to onset corona field (E cor ) [16], whose assumption is valid for a nonstationary corona when the background electric field changes slowly [19,20]. Secondly, it is assumed that only the positive corona ions are considered and move away from the corona-producing surface, while all the negative ions in the ionization layer are instantly absorbed by the anode.…”

“…In the computed method, the second-order upwind difference scheme [19,20] is used to discretize the convection terms (the second term on the right side of the (1) and (2)) from (1) to (3) in order to eliminate numerical oscillation, and the central difference scheme is used to discretize the diffusion terms (the first term on the right side of (1)- (3)). Poisson's equation is solved by the five-point finite difference method (FDM), and the successive overrelaxation (SOR) method is used for solving linear systems.…”

Two-dimensional simulation on the glow to streamer transition from horizontal conductors

“…The authors have proved through a detailed analysis of the ionization zone that Kapzov's approximation does not hold under fast changing background electric fields [17]. For that reason, it is difficult to properly estimate the conditions for the glow to streamer transition while assuming a constant surface electric field, as it has been done in previous studies [2][3][4][5][6][7][8][9][10][11][12][13][14].…”

“…For that reason, it is difficult to properly estimate the conditions for the glow to streamer transition while assuming a constant surface electric field, as it has been done in previous studies [2][3][4][5][6][7][8][9][10][11][12][13][14]. A preliminary analysis of the critical rate of rise of the applied voltage for the transition from glow to streamers has been performed taking into account the ionization in one dimension [17]. However, the actual definition of the transition requires the simulation of streamer fronts, which require of two dimensional (2D) models at least.…”