Predischarge Models in Dielectric Liquids

Abstract

This study presents self-consistent models of streamer growth using an equivalent electrical network, the only input data being the electrode geometry and the applied voltage waveform. The growth of filamentary and bushlike discharge structures are simulated. The initiation and the development of streamers are taken into account using field criteria. The streamer instantaneous propagation velocity is obtained using a model based on energetic considerations. In the case of filamentary streamers, each branch is assumed to be a cylindrical channel represented by an R C cell (R and C are, respectively, the resistance and the capacitance associated with each branch). The hazardous discharge propagation is also taken into account. In the case of bush-like structures, the envelope of streamers is assumed to be approximately spherical. For given experimental conditions (such as applied voltage and electrode geometry), we determine the streamer characteristics such as the shape and amplitude of the streamer current, the electrical charge, the velocity, power and energy injected in the gap. The developed models also enable the simulation of an image converter working in streak or frame mode and the streamer trajectory plotted in real time. An estimate of the pressure within bushlike streamer envelope is given. A good agreement between computed and experimental results has been obtained.

Plasmas in liquids and some of their applications in nanoscience

“…In recent reports by Ceccato and co-workers [Ceccato 2009a, Ceccato et al 2009, Ceccato et al 2010 there are excellent summaries of the temporal development of a high voltage, large gap plasmas in water from a positively biased pin to a grounded plane electrode in water based on their measurements which enhance but are largely consistent those of others [Beroual et al 1988, Beroual 1993, Lesaint and Gournay 1994, Fofana and Beroual 1998, Massala and Lesaint 1998, Vasily et al 2007]. The spatially and temporally resolved evolution of the system is recorded by imaging of the light emission from the plasma and the refraction of backlighting light using shadowgraphy.…”

Dynamic modeling of AC arc development on ice surfaces

“…The total resistance of a conductive surface layer is a function of its surface conductivity which changes dynamically during different stages of arc propagation [40]. Recent research has revealed that the capacitance of a test object in the form of a rod-plane is non-linear [57]. The above facts dictate the use of non-linear and time-variant circuit elements.…”

Photoionization model for streamer propagation mode change in simulation model for streamers in dielectric liquids

“…Developing predictive models and simulations is challenging, but many attempts exist [8,9]. Simulations have often focused on one aspect of the problem, such as the electric field [10,11], production of free electrons [12], conductance of the streamer channels [13], inhomogeneities [14], or the plasma within the channels [15].…”