Research on Electric Field Strength Distortion near the Insulators When There Is Any Guano-Caused Flashover of Insulators of Power Transmission Lines

Author(s):  
Jingwen Zheng ◽  
Yuchao Li
2017 ◽  
Vol 29 (5) ◽  
pp. 1415-1422 ◽  
Author(s):  
Hongwei Zhou ◽  
Liping Sun ◽  
Yang Yang ◽  
Che Liu ◽  
Tianshi Liu ◽  
...  

2013 ◽  
Vol 16 (4) ◽  
pp. 43-52
Author(s):  
Tu Phan Vu

The HVDC transmission lines have been building in many modern countries in all over the world, and it will be an important problem of Viet Nam power transmission. The important phenomena of operation of HVDC transmission lines is corona discharge around HVDC transmission lines that is a cause to increase significantly the electric field strength over ground surface and around lines. This paper presents the investigation and calculation of the electric field strength of many models of HVDC transmission lines such as monopolar, bipolar, single- and double-circuit using the finite element method based on COMSOL MULTIPHYSICS software. The calculation results have shown the strength and shape of the electric field strength at many positions over ground level. These results are also good datum to calculate and design HVDC transmission lines of Viet Nam power transmission in the near future.


2018 ◽  
Vol 11 (3) ◽  
pp. 222-226
Author(s):  
M. V. Timofeeva

Accidents in power transmission lines under icing conditions, in particular, those of cables, cause a great economic damage in Russia. Because of the lack of the possibility to forecast and evaluate reliably the consequences of weather conditions contributing to icing of transmisison line cables, power grid services often have to go to the place of a potential accident relying on guesswork. This leads to considerable losses of time and material resources, while the average recovery time of a damaged high voltage power transmission line is 5–10 days.For the effective prediction and timely prevention of negative consequences of icing of on power line cables, an analytical model that describes the growth of ice on the surface of the electrical cable has been developed. The model is based on a widely applicable analytical model of [1], supplemented with dependence of the growth of ice sleeve on the angle between the wind direction and the cable, and on the electric field strength of the cable.The results obtained using the new analytical model and the [1], model have been compared and show that as the angle between the wind direction and the cable decreases, the intensity of the ice growth decreases significantly. At the same time, the strength of the electric field of the cable affects negligibly the trajectory of water droplets.A conclusion is drawn about insignificance of electrical field strength of the electric cable as a factor of growth of ice deposits. It is stated that the ice thickness value obtained using the developed model can be increased under specific weather conditions and design parameters of transmission lines. The obtained model can be improved by using other physical effects that affect icing of electric cables. Further, the model can be introduced in operation of energy companies to monitor the condition of power transmission lines and to carry out anti-icing activities.


2017 ◽  
Vol 66 (3) ◽  
pp. 595-605 ◽  
Author(s):  
Ramūnas Deltuva ◽  
Robertas Lukočius

AbstractIn Lithuanian and Polish electric power supply systems, the power transmission lines of 400 kV voltage represent one of the most potential sources of electric and magnetic fields generation. The 400 kV double-circuit overhead power transmission line and its surrounding environment were herby described and simulated through Finite Element Method usingCOMSOL Multiphysicsoftware package. This study includes magnetic and electric field calculations. The study shows that the values of magnetic field strength and electric field strength present in the vicinity of a 400 kV overhead power transmission line tend to exceed limit values established in the Normative. Measurements are suggested to be taken for the purpose of finding maximum values of magnetic and electric field strength. To reduce these values, it is recommended to increase the height of supports, and restrict human personal and economic activities.


2015 ◽  
Vol 16 (2) ◽  
pp. 207
Author(s):  
Hussein Ahmad ◽  
Mohd Hafizi Ahmad ◽  
Noor 'Aliaa Awang ◽  
Izzah Hazirah Zakaria

<p>Electromagnetic radiations present in the environment has a profound effect on the growth of vegetable plant primarily grown under the high power transmission lines. The high electric field generated due to ultra high voltage causes the increase and reduction in the size of the plants. Numerous research have been carried out to investigate the effect of electric field on the plants. However, the knowledge in term of quantitative analysis on the effect of electric field on the growth of vegetables is not entirely understood. Thus, this paper presents a study conducted to investigate the effect of high voltage DC electric fields on the young vegetables growth namely ‘Choy Sam’ and bean sprout. The experimental setup was designed which composed of two parallel plate electrodes. This research was focused on the percentage of germination and growing rate of young vegetables. The growth of the young vegetables during exposure was calculated by using statistical methods. The analysis of the results showed that the electric fields and the electric fields treated water have influenced the germination rate and height of stems of both young vegetables causing the increase in stem height.</p><p> </p>


Author(s):  
ANDREW SEAGAR ◽  
SALAKCHIT NILBOWORN

It is important to calculate the electric field at the surface of high voltage direct current power transmission lines, since it is this field which governs the onset of corona discharge and the power loss arising therefrom. A method is presented here to calculate the electric field based on an implementation of the boundary element method for conductors of strictly circular cross section. Given the circular geometry it is possible to resolve all integrals involved analytically. A Galerkin approach is adopted, giving the solution in the spatial frequency domain. That allows a controlled truncation of the system matrix by choice of which frequency components to keep. It transpires that the low frequency components are the most important ones. Two test cases are used to quantify the accuracy of the solution with respect to truncation and distance from the surface. It is found that the accuracy increases with distance from the surface, but for all distances can be controlled by choosing an appropriate level of truncation.


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