scholarly journals MECHANISMS AND INFLUENCE FACTORS OF DYNAMIC BEHAVIOR OF WATER DROPLETS ON THE COMPOSITE INSULATOR SURFACE UNDER AC ELECTRIC FIELD

2021 ◽  
Vol 98 ◽  
pp. 9-16
Author(s):  
Wen Cao ◽  
Hua Feng ◽  
Hao Xue ◽  
Wei Shen ◽  
Long Zhao ◽  
...  
Keyword(s):  
Electric Field ◽  
Dynamic Behavior ◽  
Influence Factors ◽  
Water Droplets ◽  
Composite Insulator ◽  
Insulator Surface ◽  
Ac Electric Field

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.

scholarly journals Dynamic behavior of water droplets on wetted superhydrophobic surfaces under a high AC electric field

AIP Advances ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 065307 ◽  
Author(s):  
Shichao Wei ◽  
Haiyun Jin ◽  
Huimin Zhou ◽  
Kunpeng Yang ◽  
Naikui Gao ◽  
...  
Keyword(s):  
Electric Field ◽  
Dynamic Behavior ◽  
Superhydrophobic Surfaces ◽  
Water Droplets ◽  
Ac Electric Field

The Distinguishing Quality of Water Droplets on Insulating Surface under AC and DC Electric Field Stress

2014 ◽  
Vol 1025-1026 ◽  
pp. 803-808
Author(s):  
Sackthavy Chandavong ◽  
Kittipong Tonmitr ◽  
Arkom Kaewrawang
Keyword(s):  
Electric Field ◽  
Water Droplets ◽  
Insulating Material ◽  
Field Stress ◽  
Ac Electric Field ◽  
Quality Of Water ◽  
Electric Field Direction ◽  
Surface Breakdown ◽  
Dc Electric Field

This paper presents the comparison of water droplets on insulating surface under alternating current (AC) and direct current (DC) electric field. Besides that, it is demonstrated about the insulator deterioration under both electric field stressed due to an ageing and partial discharge (PD) phenomenon. The vital parameters factors are water droplets conductivity, droplet volume, surface roughness and droplet positioning that they cause to occur the electric field intensification. The field is intensified at the interface between the droplet, air and insulating material. Thus, the PD occurred due to electric field intensification increases with the deformed droplet. The deformation of water droplet under AC electric field stress is more intense than DC field. The electrostatic forces change the droplet shapes and spread them along the electric field direction. The local electric field intensification provokes the PD giving way to reduction of hydrophobicity of insulator surfaces. In addition, the PD activity could appear as a trigger for a surface breakdown. And the localized arcs cause damage to insulating material then finally leads to deterioration of insulation materials and the pollutant contamination.

Numerical Simulation of Leakage Current on Conductive Insulator Surface

2019 ◽  
Vol 8 (4) ◽  
pp. 9487-9492
Keyword(s):  
Numerical Simulation ◽  
Electric Field ◽  
Leakage Current ◽  
Method Of Lines ◽  
Electron Attachment ◽  
Negative Ions ◽  
Conduction Current ◽  
Insulator Surface ◽  
Finite Difference Approximations ◽  
Positive Ions

The outdoor insulator is commonly exposed to environmental pollution. The presence of water like raindrops and dew on the contaminant surface can lead to surface degradation due to leakage current. However, the physical process of this phenomenon is not well understood. Hence, in this study we develop a mathematical model of leakage current on the outdoor insulator surface using the Nernst Planck theory which accounts for the charge transport between the electrodes (negative and positive electrode) and charge generation mechanism. Meanwhile the electric field obeys Poisson’s equation. Method of Lines technique is used to solve the model numerically in which it converts the PDE into a system of ODEs by Finite Difference Approximations. The numerical simulation compares reasonably well with the experimental conduction current. The findings from the simulation shows that the conduction current is affected by the electric field distribution and charge concentration. The rise of the conduction current is due to the distribution of positive ion while the dominancy of electron attachment with neutral molecule and recombination with positive ions has caused a significant reduction of electron and increment of negative ions.

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