Electro-quasistatic calculation of electric field strength on high-voltage insulators with an algebraic multigrid algorithm

2003 ◽  
Vol 39 (4) ◽  
pp. 2129-2132 ◽  
Author(s):  
S. Reitzinger ◽  
U. Schreiber ◽  
U. van Rienen
Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2671 ◽  
Author(s):  
Jordi-Roger Riba ◽  
Andrea Morosini ◽  
Francesca Capelli

Due to the expansion of high-voltage direct current (HVDC) power systems, manufacturers of high-voltage (HV) hardware for alternating current (ac) applications are focusing their efforts towards the HVDC market. Because of the historical preponderance of ac power systems, such manufacturers have a strong background in ac corona but they need to acquire more knowledge about direct current (dc) corona. Due to the complex nature of corona, experimental data is required to describe its behavior. This work performs an experimental comparative analysis between the inception of ac corona and positive and negative dc corona. First, the sphere-plane air gap is analyzed from experimental data, and the corona inception voltages for different geometries are measured in a high-voltage laboratory. Next, the surface electric field strength is determined from finite element method simulations, since it provides valuable information about corona inception conditions. The experimental data obtained are fitted to an equation based on Peek’s law, which allows determining the equivalence between the visual corona surface electric field strength for ac and dc supply. Finally, additional experimental results performed on substation connectors are presented to further validate the previous results by means of commercial high-voltage hardware. The results presented in this paper could be especially valuable for high-voltage hardware manufacturers, since they allow determining the dc voltage and electric field values at which their ac products can withstand free of corona when operating in dc grids.


2013 ◽  
Vol 781-784 ◽  
pp. 372-378
Author(s):  
Xing Ke Ma ◽  
Zheng Wei Du ◽  
Min Zhu ◽  
Bo Jia Mu

At present, indirect effects of high-voltage electrostatic field on organisms and biological materials have been extensively studied. However, the investigations on direct interaction between the electrostatic field and enzyme are scarce. In this paper, the direct effect of high-voltage electrostatic field on the LP and the protective effects of sucrose fatty acid ester on the activity of enzyme in high-voltage electrostatic field have been experimentally investigated. The results show that, high-voltage electrostatic field has direct effects on the LP and the best condition to enhance the activity of enzyme can be obtained. When the electric-field strength is low, with the increasing of the electric-field strength, the activity of the LP will be weakened. When the electric-field strength exceeds a certain level, the activity of the LP will be enhanced with the increasing of electric-field strength. For too higher electric-field strength , the activity of the LP will be again weakened with the increasing of electric-field strength. The sucrose fatty acid ester in low concentration provides a proper hydrophobic microenvironment for enzyme, which leads to the enhancement of enzyme's activity, while sucrose fatty acid ester in high concentration leads to the weakening of enzyme's activity. Moreover, sucrose fatty acid ester in enzyme solutions has protective effects on enzyme in the electric field and can reduce the impacts of high-voltage electrostatic field on the LP.


2021 ◽  
Vol 16 (95) ◽  
pp. 126-135
Author(s):  
Evgeniy S. Andreenkov ◽  
◽  
Vaclav E. Skorubskiy ◽  
Sergey A. Shunaev ◽  
◽  
...  

The article discusses the main aspects of modeling suspended polymer high-voltage insulation of overhead power lines (PTL) in the COMSOL Multiphysics 5.6 software package. Analytical expressions of the mathematical model of the electromagnetic field around the insulator are given, on the basis of which a numerical solution is formed within the software package that allows you to build a model of the electric field in two-dimensional and three-dimensional space. There are three main stages of working with the program interface. At the first stage, the task of the geometric dimensions of the model and the surrounding area is considered, attention is paid to the formation of the design features of polymer insulators. In the second stage, the physical properties of the structural materials of the insulator, as well as the surrounding space, are described. The third stage is reduced to the determination of boundary conditions for solving the Poisson differential equation. Recommendations for finite element mesh density are given. A gradient picture of the distribution of the electric potential near the surface of the insulator is presented. The graphs of the distribution of the normal component of the electric field strength along the surface of the insulator are also plotted. On the basis of the obtained results, the influence of external factors on the properties of the polymer insulator is studied. A possible variant of modeling influencing factors, such as pollution and moisture, by making changes in the description of the physical properties of the insulator surface, namely by including a uniform and continuous layer with a given conductivity, is described. The distribution of the normal component of the electric field strength along the surface of the insulator with contamination is obtained. The results of modeling the electric field distribution with the presence of contamination on the surface of the insulator and its absence are summarized in the table where the electric field strength is indicated depending on the distance to the traverse. Based on the analysis of the results obtained, an assumption is made about the overestimated level of the maximum electric field on the insulators recommended by the manufacturers. The convergence of the considered models with the experimental data obtained in the course of long-term observation of the dynamics of the degradation and aging processes of the surface of polymer suspended insulators of overhead transmission lines is discussed.


2011 ◽  
Vol 354-355 ◽  
pp. 1201-1204
Author(s):  
Xiao Bin Zhu ◽  
Tang Qin Wu ◽  
Lin He Zhang ◽  
Hai Xiang Chen

Some flashover incidents of high-voltage transmission lines are reported to be induced by fire. Though the mechanism of fire induced flashover is not well understood, it is deemed that fire could reduce the insulation strength of air. This paper has compared the breakdown characteristics of gaps in normal air conditions and those in fire. The results show that the breakdown voltage or electric field strength of gaps in fire decreases greatly. The value of breakdown electric field strength in alcohol flame is about 1.454 KV/cm, which is only about 28.8% of that in air. The value of breakdown electric field strength in wood crib fire is about 0.300KV/cm, corresponding to 19.9% of that in air. This study demonstrates that flame and soot particle of fire are responsible for fire induce flashover of high-voltage transmission lines.


2016 ◽  
Vol 136 (10) ◽  
pp. 1420-1421
Author(s):  
Yusuke Tanaka ◽  
Yuji Nagaoka ◽  
Hyeon-Gu Jeon ◽  
Masaharu Fujii ◽  
Haruo Ihori

Sign in / Sign up

Export Citation Format

Share Document