Cardiff University | Prifysgol Caerdydd ORCA
Online Research @ Cardiff 
WelshClear Cookie - decide language by browser settings

Visualization of the ionization phenomenon in porous materials under lightning impulse

Elzowawi, Alseddig, Haddad, Abderrahmane and Griffiths, Huw 2015. Visualization of the ionization phenomenon in porous materials under lightning impulse. Presented at: 9th Asia-Pacific International Conference on Lightning, Nagoya, Japan, 23-27 June 2015.

[img]
Preview
PDF - Accepted Post-Print Version
Download (633kB) | Preview

Abstract

the electric discharge and soil ionization phenomena have a great effect on the performance of earthing systems, especially under lightning currents. These phenomena create a nonlinear behaviour in the soil around the earthing electrode, where the resistivity of the soil drops to a lower value allowing the current to increase to a higher magnitude. Very limited studies have been conducted to image the soil ionization discharge developments from the earthing electrode in the soil. However, the imaging process of the electric discharge in opaque porous materials such as soil is extremely difficult. Therefore, in this study, a photographic investigation of the electric discharge in a new dielectric glass bubble material was conducted. Also the expansion of the ionization zone in this material was investigated with a specially-adapted sample configuration. A rod-plane electrode configuration was utilized in the test rig. The sample was placed in a Perspex vertical tube, so that the discharge light can be visible and recorded by a fast camera.Voltage probes were installed in the tube to measure the voltage at different places in the sample. Standard lightning and switching impulse voltages were used in these experiments. Synchronized frames of the recorded video with voltage and current waveforms allow visualization of the dynamic change of the discharge at various times during the impulse. It was observed that the expansion of the ionization zone does not have a constant speed and the resistance of the ionization zone is not the same throughout the zone.

Item Type: Conference or Workshop Item (Paper)
Date Type: Publication
Status: Unpublished
Schools: Engineering
Subjects: T Technology > TK Electrical engineering. Electronics Nuclear engineering
Date of First Compliant Deposit: 30 March 2016
Last Modified: 10 Oct 2017 16:41
URI: http://orca.cf.ac.uk/id/eprint/80515

Actions (repository staff only)

Edit Item Edit Item

Downloads

Downloads per month over past year

View more statistics