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16 pages, 3916 KiB

Open AccessArticle

Research on the Effect of an Air-Blown Interrupting Gap to Reduce the Rate of Lightning Tripping

by Hao Li, Jufeng Wang, Ping Huang, Kezhu Guo and Yanlei Wang

Energies 2023, 16(3), 1474; https://0-doi-org.brum.beds.ac.uk/10.3390/en16031474 - 02 Feb 2023

Cited by 1 | Viewed by 897

The air-blown interrupting gap protection method is a self-energy interrupting method based on the concept of suppressing arc building by frequency continuation. In order to verify the effect of an air-blown interrupting gap to reduce the rate of line lightning tripping, in this [...] Read more.

The air-blown interrupting gap protection method is a self-energy interrupting method based on the concept of suppressing arc building by frequency continuation. In order to verify the effect of an air-blown interrupting gap to reduce the rate of line lightning tripping, in this paper, the protection principle of the air-blown interrupter gap is first described, and the action process simulated by COMSOL Multiphysics simulation software. Next, a frequency renewal test circuit is built for the test. Then, an arc-building rate calculation model and a lightning trip rate calculation model under the condition of an air-blown interrupting gap are established, and, finally, a 10 kV overhead line in Yunnan is selected for the verification of the calculation example. The results show the following: a gas blowing arc gap can be effectively extinguished in about 2.5 ms frequency arc and with no re-ignition phenomenon. Before and after the installation of the gas blowing arc gap line, the arc rate changed from 37.27% to 4.1%, respectively, and the lightning trip rate changed from 8.64 times/(40 thunderstorm days—100 km) to 0.337 times/(40 thunderstorm days—100 km), respectively. The decline rate was more than 95%, and in actual operation, it reduced the lightning trip rate enough to achieve good results. Full article

(This article belongs to the Special Issue Advanced Research of High Voltage Insulation)

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14 pages, 5042 KiB

Open AccessArticle

Research on Energy Conversion in the Arc-Extinguishing Process of a Long-Gap Gas Lightning-Protection Device

by Qiwen He, Jufeng Wang, Yang Lu, Yongfeng Song, Zhenghao Jia, Hao Li, Yanlei Wang and Yiyi Zhang

Energies 2022, 15(20), 7490; https://0-doi-org.brum.beds.ac.uk/10.3390/en15207490 - 12 Oct 2022

Cited by 1 | Viewed by 1171

Abstract

In this paper, a two-dimensional axisymmetric module of gas arc extinguishing was simulated using energy balance theories. We used simulation to study the energy distribution change during the gas arc-extinguishing process. We built a lightning impulse current experimental platform according to the IEC [...] Read more.

In this paper, a two-dimensional axisymmetric module of gas arc extinguishing was simulated using energy balance theories. We used simulation to study the energy distribution change during the gas arc-extinguishing process. We built a lightning impulse current experimental platform according to the IEC standard, and experiments verified the preliminary conclusions of the simulation. Comparison curves of the experimental data and simulation calculations were drawn in the range of 20 kV to 70 kV. Simulation and experimental results showed that the arc-extinguishing ability of long-gap gas arcs is negatively correlated with voltage level and positively correlated with distance. Furthermore, within the allowable range of conditions, increasing the length of the chamber rather than shortening it helps to extinguish the arc more effectively and quickly. Full article

(This article belongs to the Special Issue Advanced Research of High Voltage Insulation)

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13 pages, 1571 KiB

Open AccessArticle

Numerical Simulation and Calculation of Resistance of Laminated Paper-Impregnated Insulation of Power Cables

by Dmitry Arsenyev, Simon Dubitsky, Dmitry Kiesewetter and Victor Malyuin

Energies 2022, 15(19), 7403; https://0-doi-org.brum.beds.ac.uk/10.3390/en15197403 - 09 Oct 2022

Cited by 2 | Viewed by 1254

Abstract

Numerical simulation of polypropylene laminated paper insulation is a serious challenge, as it must take into account the layered structure and presence of longitudinal and radial gaps in the coils of the winded tape for cables with sector-shape conductive cores. Thus far, it [...] Read more.

Numerical simulation of polypropylene laminated paper insulation is a serious challenge, as it must take into account the layered structure and presence of longitudinal and radial gaps in the coils of the winded tape for cables with sector-shape conductive cores. Thus far, it has been performed only with serious simplifications. We propose a technique for numerical modeling of electric parameters in this type of insulation by reducing a complex 3D problem to a simplified 2D model that takes into account the main influencing factors. The results of modeling the distribution of electric field strength and current density in insulation are presented, and the influence of the location of gaps between the edges of winded tape on the conductivity of cable insulation is estimated. Analytical expressions are obtained for estimating the electrical resistance of insulation while taking into account the parameters of the butt gap between the insulating tapes. The results of calculations, numerical modeling, and experimentally measured values of electrical resistance are compared, showing that there is a good match. The main effects affecting the properties of polypropylene laminated paper insulation are described. Full article

(This article belongs to the Special Issue Advanced Research of High Voltage Insulation)

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13 pages, 3113 KiB

Open AccessArticle

Simulation and Study of DC Corona Discharge Characteristics of Bar-Plate Gap

by Na Feng, Tiehua Ma, Changxin Chen, Boren Yao and Weitao Gao

Energies 2022, 15(17), 6431; https://0-doi-org.brum.beds.ac.uk/10.3390/en15176431 - 02 Sep 2022

Cited by 3 | Viewed by 2207

Abstract

In this paper, the corona discharge process of the bar-plate gap at −1 kV DC voltage is simulated using a two-dimensional axisymmetric plasma module. We analyze the variation of air negative corona discharge current, and the distribution morphology of microparticles in different discharge [...] Read more.

In this paper, the corona discharge process of the bar-plate gap at −1 kV DC voltage is simulated using a two-dimensional axisymmetric plasma module. We analyze the variation of air negative corona discharge current, and the distribution morphology of microparticles in different discharge stages in detail. The significance of plasma chemical reactions at some typical time and the distribution characteristics of heavy particles are investigated according to reaction rates. Results show that, in the current rising stage, the collision ionization reactions (e.g., R₁ and R₂) and electron adsorption reaction (e.g., R₃) play a major role, which lead to the increase in charged particles and the formation of an electron avalanche. In the current drop stage, all reaction rates decreased, except for collision ionization and electron attachment, partial charge transfer reactions (e.g., R₈, R₁₀, R₁₁, and R₁₄), and composite reactions (e.g., R₁₆, R₁₇, and R₁₈), which come into play and gradually reduce the number of charged ions in the gap. In the current stabilizing stage, the main chemical reactions are composite reactions (e.g., R₁₆ and R₁₇), then the corona discharge ends. For the heavy particle distribution, O₂⁺ and O₄⁺ are the main positive ions, O₂⁻ is the most abundant negative ions, and the neutral particles are mainly O. Full article

(This article belongs to the Special Issue Advanced Research of High Voltage Insulation)

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18 pages, 3868 KiB

Open AccessArticle

Study on the Algae Contamination and Its Effects on the Properties of RTV-Coated Insulators

by Yawei Li, Zhibo Song, Yuan Tian, Chao Yang, Fenglian Liu, Huan Bai, Fuping Zhao, Xingwen Liu and Hao Yang

Energies 2022, 15(14), 5216; https://0-doi-org.brum.beds.ac.uk/10.3390/en15145216 - 19 Jul 2022

Cited by 2 | Viewed by 1315

Abstract

The surface of organic insulating materials such as room temperature vulcanized silicone rubber (RTV) coatings often has serious contamination deposition. In humid areas such as the Southwest region of China, algae contamination layers are present on the surface of the insulators. In this [...] Read more.

The surface of organic insulating materials such as room temperature vulcanized silicone rubber (RTV) coatings often has serious contamination deposition. In humid areas such as the Southwest region of China, algae contamination layers are present on the surface of the insulators. In this study, the geographical and creeping distribution of algae contamination on the surfaces of RTV insulators were studied by investigating and sampling various substations in the Southwest region. The main components of soluble salts in the contamination were studied by atomic absorption spectroscopy and ion chromatography. The algal genome was extracted by the cetyltrimethylammonium bromide method, and the species of algae and other microorganisms in the contamination layer were determined. The effects of algae or their secretions on the surface resistance and hydrophobicity were studied by quantitatively inoculating algae and smearing extracellular secretions on the RTV surface. The damage of the algae contamination layer to the microstructure of the silicone rubber was investigated by microscopic observation and thermogravimetric analysis. Results showed that the growth of algae was positively correlated with the surface contamination of RTV. The extracellular secretion of algae destroys the surface microstructure of RTV and causes the removal of alumina hydroxide, leading to the reduction of siloxane. Therefore, the resistance and hydrophobicity of the RTV surface were reduced. It is of great significance to study the characteristics and effects of the algae contamination layer for RTV maintenance. Full article

(This article belongs to the Special Issue Advanced Research of High Voltage Insulation)

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14 pages, 584 KiB

Open AccessArticle

Electric Field Distribution and Dielectric Losses in XLPE Insulation and Semiconductor Screens of High-Voltage Cables

by Zbigniew Nadolny

Energies 2022, 15(13), 4692; https://0-doi-org.brum.beds.ac.uk/10.3390/en15134692 - 26 Jun 2022

Cited by 6 | Viewed by 2867

Abstract

This article presents the electric field distribution E and dielectric losses ΔP_diel. in the insulation system of high-voltage cables. Such a system consists of inner and outer semiconductor screens and XLPE insulation. The aim of this study was to compare the values [...] Read more.

This article presents the electric field distribution E and dielectric losses ΔP_diel. in the insulation system of high-voltage cables. Such a system consists of inner and outer semiconductor screens and XLPE insulation. The aim of this study was to compare the values of E and ΔP_diel. between semiconductor screens and XLPE insulation. The objects of the research were high-voltage cables of 110 kV, 220 kV, 400 kV, and 500 kV. The geometrical dimensions of the cables, especially the radii of individual layers of insulation, as well as the electrical properties of the screens and XLPE, were taken from the literature. Semiconductor screens and XLPE insulation were treated as a system of three concentric cylinders. When determining the electric field distribution, both the electrical permittivity and electrical conductivity, which, in the case of semiconductor screens, play important roles, were taken into account. The obtained results prove that both the electric field distribution E and dielectric losses P_diel. are significantly larger in XLPE insulation than in semiconductor screens. The intensity E in XLPE insulation is about four orders of magnitude greater than the intensity in semiconductor screens. Dielectric losses ΔP_diel. in XLPE insulation are about eight orders of magnitude greater than the losses occurring in semiconductor screens. Full article

(This article belongs to the Special Issue Advanced Research of High Voltage Insulation)

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21 pages, 7512 KiB

Open AccessArticle

Effect of Seawater and Fly Ash Contaminants on Insulator Surfaces Made of Polymer Based on Finite Element Method

by I Made Yulistya Negara, I. G. N. Satriyadi Hernanda, Dimas Anton Asfani, Mira Kusuma Wardani, Bonifacius Kevin Yegar and Reynaldi Syahril

Energies 2021, 14(24), 8581; https://0-doi-org.brum.beds.ac.uk/10.3390/en14248581 - 20 Dec 2021

Cited by 2 | Viewed by 2283

Abstract

Polymer is an insulating substance that has become increasingly popular in recent years due to its benefits. Light density, superior dielectric and thermal properties, and water-resistant or hydrophobic properties are only a few of the benefits. The presence of impurities or pollutants on [...] Read more.

Polymer is an insulating substance that has become increasingly popular in recent years due to its benefits. Light density, superior dielectric and thermal properties, and water-resistant or hydrophobic properties are only a few of the benefits. The presence of impurities or pollutants on the insulator’s surface lowers its dielectric capacity, which can lead to current leakage. The influence of seawater and fly ash pollutants on the distribution of the electric field and the current density of the insulator was simulated in this study. The finite element method was used to execute the simulation (FEM). Polymer insulators are subjected to testing in order to gather current leakage statistics. The tested insulator is exposed to seawater pollution, which varies depending on the equivalent salt density deposit value (ESDD). The pollutant insulator for fly ash varies depending on the value of non-soluble deposit density (NSDD). The existence of a layer of pollutants increased the value of the electric field and the value of the surface current density, according to the findings. Both in simulation and testing, the ESDD value of seawater pollutants and the NSDD value of fly ash contaminants influenced the value of the leakage current that flowed. The greater the ESDD and NSDD values are, the bigger the leakage current will be. Full article

(This article belongs to the Special Issue Advanced Research of High Voltage Insulation)

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Review

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17 pages, 2015 KiB

Open AccessReview

Overview of Research Status of DC Bias and Its Suppression in Power Transformers

by Youliang Sun, Li Zhang, Zhuangzhuang Zhang and Dong Wang

Energies 2022, 15(23), 8842; https://0-doi-org.brum.beds.ac.uk/10.3390/en15238842 - 23 Nov 2022

Cited by 3 | Viewed by 1474

Abstract

In this article, the sources of DC bias and its effects on power transformers are first summarized. Secondly, the article classifies and summarizes the current DC bias calculation problems of power transformers, and puts forward some interesting viewpoints on the research logic of [...] Read more.

In this article, the sources of DC bias and its effects on power transformers are first summarized. Secondly, the article classifies and summarizes the current DC bias calculation problems of power transformers, and puts forward some interesting viewpoints on the research logic of related calculations. The current processing methods of DC bias effect are classified and discussed, their advantages and disadvantages are compared, and the logic flow of DC bias effect processing is proposed. Finally, the current research on DC bias voltage of power transformers is summarized, and the progress and deficiencies of current research are pointed out, which has certain reference value for future research on DC bias voltage and its suppression. Full article

(This article belongs to the Special Issue Advanced Research of High Voltage Insulation)

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