scholarly journals Study of the Behavior of Water Droplets Under the Influence of a Uniform Electric Field on Conventional Polyethylene and on Crosslinked Polyethylene (XLPE) with MgO Nanoparticles Samples

2017 ◽  
Vol 7 (1) ◽  
pp. 1323-1328 ◽  
Author(s):  
C. Charalambous ◽  
M. Danikas ◽  
Y. Yin ◽  
N. Vordos ◽  
J. W. Nolan ◽  
...  
Keyword(s):  
Electric Field ◽  
Uniform Electric Field ◽  
Water Droplets ◽  
Nano Structure ◽  
Insulating Materials ◽  
Mgo Nanoparticles ◽  
Underground Cables ◽  
Flashover Voltage ◽  
Surface Damages ◽  
Water Drops

It is well known that polyethylene (PE) and cross-linked polyethylene (XLPE) are suitable insulating materials for underground cables. Samples of PE and of XLPE with MgO nanoparticles were investigated regarding their flashover behaviour with a uniform electric field and water droplets of various conductivities. In the present paper, the effect of the mounting arrangement of the water drops on the value of the flashover voltage and the effect of the volume of dripping water on the flashover voltage were also studied. Surface damages were analyzed using Scanning Electron Microscopy (SEM) studies and the study of the nano-structure of the samples was studied using the SAXS system.

Study on Discharge of Separated Water Droplets in DC Field

2011 ◽  
Vol 130-134 ◽  
pp. 3276-3279
Author(s):  
Zong Xi Zhang ◽  
Shan Feng Yin
Keyword(s):  
Electric Field ◽  
Hydrophobic Surface ◽  
Electrical Equipment ◽  
Water Droplets ◽  
Surface Flashover ◽  
Voltage Drops ◽  
Flashover Voltage ◽  
Dc Electric Field ◽  
Water Drops ◽  
And Migration

With the accelerating construction of strong smart grid, and the grid voltage level rising, performance requirements for the electrical insulation of electrical equipment also continue to increase. In terms of the advantages of RTV on antifouling, RTV-based paints coated insulator coating capacity of its flash tolerance can significantly increase, mainly due to RTV coating hydrophobic hydrophobicity and migration. But when the hydrophobic surface is in the fully wet, many small drops of water in the surface will be gathered into big drops of water, and these large droplets will distort the surface electric field of the medium. So the flashover voltage of the hydrophobic surface’s separated water droplets under DC electric field are analyzed comparatively in this paper, while some influencing factors such as different medias and volume of water drops, are introduced in specific experiments, and their effects on the flashover voltage are analyzed; under DC electric field experiment on the surface of hydrophobic and hydrophilic surface flashover voltage drops separation characteristics were studied.

scholarly journals A Study of the Behaviour of Water Droplets Under the Influence of Uniform Electric Field in Epoxy Resin Samples

2012 ◽  
Vol 63 (3) ◽  
pp. 196-200 ◽  
Author(s):  
Yonghong Cheng ◽  
Xu Zhao ◽  
Michael Danikas ◽  
Despoina Christantoni ◽  
Pavlos Zairis
Keyword(s):  
Electric Field ◽  
Epoxy Resin ◽  
Electric Fields ◽  
Uniform Electric Field ◽  
Droplet Volume ◽  
Water Droplets ◽  
Water Conductivity ◽  
Volume Number ◽  
Flashover Voltage ◽  
Droplet Behavior

A Study of the Behaviour of Water Droplets Under the Influence of Uniform Electric Field in Epoxy Resin SamplesWater droplets on the surface of epoxy resin samples were investigated under the influence of uniform electric fields. Several parameters of water droplets were investigatedwrtthe flashover voltage of the epoxy resin samples, such as water conductivity, droplet volume, number of droplets as well as the positioning of the droplets regarding the electrodes. The droplet behavior is affected by the above mentioned parameters. Perhaps the most striking conclusion is that the flashover voltage depends more on the positioning of the dropletswrtthe electrodes than on the droplet volume and/or number of droplets.

scholarly journals Behaviour of Water Droplets Under the Influence of a Uniform Electric Field in Nanocomposite Samples of Epoxy Resin/TiO2

2013 ◽  
Vol 3 (5) ◽  
pp. 511-515 ◽  
Author(s):  
Α. Bairaktari ◽  
M. Danikas ◽  
X. Zhao ◽  
Y. Cheng ◽  
Y. Zhang
Keyword(s):  
Electric Field ◽  
Epoxy Resin ◽  
Tio2 Nanoparticles ◽  
Water Droplet ◽  
Uniform Electric Field ◽  
Droplet Volume ◽  
Water Droplets ◽  
Water Conductivity ◽  
Flashover Voltage

In this paper nanocomposite samples of epoxy resin and TiO2 nanoparticles were investigated with water droplets on their surface. A uniform electric field was applied and the behaviour of the water droplets was observed. Parameters that were studied were the water conductivity, the droplet volume, the number of droplets and the droplet positioning with respect to (w.r.t.) the electrodes. All above mentioned parameters influence the flashover voltage of the samples. It is to be noted that – at least in some cases – the water droplet positioning w.r.t. the electrodes was more important in determining the flashover voltage than the droplet volume.

The vibration of electrified water drops

1971 ◽  
Vol 322 (1551) ◽  
pp. 523-534 ◽  
Keyword(s):  
Electric Field ◽  
Electric Fields ◽  
Axial Ratio ◽  
Uniform Electric Field ◽  
Interferometric Technique ◽  
Photographic Analysis ◽  
Wide Range ◽  
Water Drops ◽  
Strength And Deformation ◽  
A Charge

Pressure has been used as the principal parameter in calculations of the fundamental vibrational frequencies of spherical drops of radius R , density ρ, and surface tension T carrying a charge Q or uncharged spheroidal drops of axial ratio a / b situated in a uniform electric field of strength E . Freely vibrating charged drops have a frequency f = f 0 ( 1 - Q 2 /16π R 3 T ) ½ , as shown previously by Rayleigh (1882) using energy considerations; f 0 is the vibrational frequency of non-electrified drops (Rayleigh 1879). The fundamental frequency of an uncharged drop in an electric field will decrease with increasing field strength and deformation a / b and will equal zero when E ( R )/ T ) ½ = 1.625 and a / b = 1.86; these critical values correspond to the disintegration conditions derived by Taylor (1964). An interferometric technique involving a laser confirmed the accuracy of the calculations concerned with charged drops. The vibration of water drops of radius around 2 mm was studied over a wide range of temperatures as they fell through electric fields either by suspending them in a vertical wind tunnel or allowing them to fall between a pair of vertical electrodes. Photographic analysis of the vibrations revealed good agreement between theory and experiment over the entire range of conditions studied even though the larger drops were not accurately spheroidal and the amplitude of the vibrations was large.

The Effect of Deterioration on Insulating Surface due to Flashover under AC Electric Field Stressed by Water Droplets

2014 ◽  
Vol 931-932 ◽  
pp. 979-983
Author(s):  
Sackthavy Chandavong ◽  
Kittipong Tonmitr ◽  
Arkom Kaewrawang
Keyword(s):  
Electric Field ◽  
Water Drop ◽  
Partial Discharge ◽  
Water Droplets ◽  
Humidity Effect ◽  
Insulator Surface ◽  
Ac Electric Field ◽  
Flashover Voltage ◽  
Alternative Current ◽  
Lower Voltage

This paper presents the effect of the flashover on insulating surface under alternative current (AC) electric field stressed by humidity factor. It is obviously demonstrated about the insulator deterioration due to an ageing, partial discharge (PD) when it is used in services. Epoxy resin with the water droplets is brought to test by high voltage AC until flashover voltage levels. The flashover level on insulator surface depends on the volume and the number of the water droplets. The highest flashover voltage is 52.2 kV for the insulator surface without humidity, but the lowest voltage is 43.5 kV for water droplets of 1, 2, 3 and 4 drops (0.5, 1.0, 1.5 and 2.0 ml). Consequently, it leads to use the lower voltage respectively. The deformation of the water drop was oscillated, moved, elongated and broken up in to a several small drops on insulating surface. PD was the result of the flashover phenomena which causes the damage of the insulator. These results lead to protect the insulator surface under humidity effect from flashover phenomena.

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