scholarly journals A new grounding model for complex soil environments

2019 ◽  
Vol 118 ◽  
pp. 03001
Author(s):  
Chong Pan ◽  
Dong Zhao ◽  
Xuesong Tu ◽  
Shuqin Wang ◽  
Tie Liu ◽  
...  
Keyword(s):  
Surface Potential ◽  
Transmission Lines ◽  
Normal Operation ◽  
Long Distance ◽  
Grounding System ◽  
Grounding Resistance ◽  
Resistance Surface ◽  
Resistance Reduction ◽  
The Common ◽  
Grounding Electrode

The purpose of arranging the grounding electrode is to discharge large currents, such as fault current and ensure the transmission line operate safely. In the grounding system of Chinese transmission network, the common grounding electrodes are horizontal installation and vertical installation. But two installation methods usually have the disadvantages, which are long distance installation and large depth burying, and they are restricted susceptible to uncertain factors such as pipelines, roads and geology, which leads the grounding resistance increasing and affect the normal operation of transmission lines. In order to solve the problem, this paper presents a new grounding model for complex soil environments and analysis from grounding resistance, surface potential and current distribution. The results show that the helix grounding electrode has good resistance reduction performance in complex soil environment, which effectively improves the surface potential distribution and the distribution of the spill current.

scholarly journals A modeling analysis of grounding resistance and sea surface potential on the jacket foundation offshore wind turbines

2018 ◽  
Vol 72 ◽  
pp. 01004
Author(s):  
Shiqi Tao ◽  
Xiaoqing Zhang ◽  
Yaowu Wang
Keyword(s):  
Surface Potential ◽  
Wind Turbines ◽  
Three Dimensional ◽  
Influential Factors ◽  
Sea Surface ◽  
Offshore Wind ◽  
Grounding System ◽  
Grounding Resistance ◽  
Offshore Wind Turbines ◽  
Modeling Analysis

Offshore wind turbines (WTs) are frequently exposed to the risk from lightning, storm, and waves. As a kind of fixed foundations, jacket foundation can effectively reduce the correlatively risk and loss. In order to provide more information about the lightning protection of jacket foundation, a simulation model has been built by simplifying the hollow steel tubes into a series of solid steel cylinders. And some conclusions on the grounding resistance of jacket foundation have been summarized in this paper by using the GSSAS (Grounding System Safe Analysis Software). According to the simulation results, the actual influential factors of grounding resistance, including the depth of seawater, the thickness of clay layer and the resistivity of gravel layer, have been analysed and compared. It is found that the grounding resistance is influenced most severely by the depth of seawater. In addition, the values of sea surface potential have been calculated by the software GSSAS and the three-dimensional diagrams of potential distribution have been mapped out.

An Experimental Study on the Electrical Properties of Fly Ash in the Grounding System

2006 ◽  
Vol 7 (2) ◽  
Author(s):  
Shin-Der Chen ◽  
Li-Hsiung Chen ◽  
Chih-Kun Cheng ◽  
Jiann-Fuh Chen
Keyword(s):  
Fly Ash ◽  
Power Systems ◽  
Power Plants ◽  
Bottom Ash ◽  
Waste Utilization ◽  
Mineral Admixture ◽  
Attractive Alternative ◽  
Grounding System ◽  
Grounding Resistance ◽  
Resistance Reduction

A good grounding system is the fundamental insurance to keep the safe operation of power systems. The grounding resistance reduction additive-fly ash is proposed in this study. Fly ash is the byproduct of coal-fired power plants. A pulverized coal boiler generates approximately 80% fly ash and only 20% bottom ash. Furthermore, the study of these materials will assume greater importance. Waste utilization is an attractive alternative to disposal in that disposal cost and potential pollution problems are reduced. Extensively used as an additive in Portland cement or as a mineral admixture in concrete in recent years, we have found that fly ash has a low resistivity, and so can be used as an agent for reducing resistance to grounding. Also, an effort is made to investigate the effect of water-to-cement(W/C) and temperature on the resistivity of the test specimens. The grounding resistance reduction agent was determined by considering various proportions of water, cement and salt. Experimental results demonstrate that the proposed approach can effectively reduce the grounding resistance.

scholarly journals Pengembangan Sistem Penangkal Petir dan Pentanahan Elektroda Rod dan Plat

2016 ◽  
Vol 3 (2) ◽  
pp. 66
Author(s):  
Makmur Saini ◽  
A.M. Shiddiq Yunus ◽  
Andareas Pangkung
Keyword(s):  
Transmission Lines ◽  
Private Property ◽  
Soil Conditions ◽  
Moist Soil ◽  
Grounding System ◽  
Grounding Resistance ◽  
High Rise ◽  
Specific Objective ◽  
Dry Conditions ◽  
Electrode Plate

The specific objective of this research is to producea system of internallightning and Eksternal lightning rod withgrounding which has been widely used in industries such aslightning protection and grounding system of substation,transmission lines and coupling wire used in high-rise buildingseither belong to government or private property. In this study,lightning rod is located outside the building structure that servesto catch or receive the bolt of lightning and the lightning deliverto the ground safely. In this study there were 5 different depths ofelectrode rod; 3 m, 5 m, 7 m, 9 m, and 12 m, moreover, 5 widevariety of electrode plate that are 1 x 1 m2, 0.75 x 0.75 m2, 0.5 x0.5 m2, 0.35 x 0.35 m2, 0.25 x 0.25 m2. For grounding electrode rod with a depth of 3 m, 5 m, 7 m, 9 m, 12 m in dry conditions grounding resistance values obtained ranged from 1.55 to 2.03 Ohm. For moist soil conditions, grounding resistance values obtained ranged from 2.21 to 2.60 Ohm. For wet soil conditions grounding resistance values obtained ranged from 1.97 to 2.34 Ohm. For grounding plate, R11 and R12 on the dry conditions grounding resistance values obtained ranged from 2.08 to 2.45 Ohm. For moist soil conditions grounding resistance values obtained ranged from 1.88 to 2.18 Ohm. For wet soil conditions grounding resistance values obtained ranged from 1.55 to 2.06 Ohm. On the external lightning rod with two added electrodes with a depth of 12 m and then connected in parallel with the electrode plate to get the smallest value of grounding resistance in accordance with the standards prescribed.

scholarly journals Helix grounding electrode with good grounding performance

2019 ◽  
Vol 277 ◽  
pp. 03007 ◽  
Author(s):  
Zhanlong Zhang ◽  
Yihua Dan ◽  
Daojun Mei ◽  
Jing Zou ◽  
Peiyu Jiang
Keyword(s):  
Surface Potential ◽  
Surface Current ◽  
Current Density Distribution ◽  
Electrical Equipment ◽  
Installation Space ◽  
Stable Operation ◽  
Surface Current Density ◽  
Grounding Resistance ◽  
Step Voltage ◽  
Grounding Electrode

Grounding electrode is used for discharging current and ensure the safe and stable operation of electrical equipment. Grounding performance of grounding electrode will degradation with limited installation space. This paper proposes helix grounding electrode and builds theoretically and simulating model on the helix grounding electrode. Analyzing grounding surface potential and step voltage distribution, grounding resistance and surface current density distribution. Results show helix grounding electrode can reduce grounding resistance, improve grounding surface potential distribution and the discharging current distribution.

scholarly journals Analysis of the effect of explosion grounding electrode on grounding resistance reduction

2019 ◽  
Vol 2019 (16) ◽  
pp. 3251-3254
Author(s):  
Yongli Wang ◽  
Sen Wang ◽  
Jian Zhang ◽  
Zhizhong Li ◽  
Li Xu
Keyword(s):  
Grounding Resistance ◽  
Resistance Reduction ◽  
Grounding Electrode

Experimental Study on the Ground Resistance Reduction Based on Different Types of Grounding Rod

2015 ◽  
Vol 793 ◽  
pp. 105-109
Author(s):  
Arfah Ahmad ◽  
Ahmad Tarmizi Azily ◽  
Anis Niza Ramani ◽  
Intan Azmira Wan Abdul Razak ◽  
Suziana Ahmad
Keyword(s):  
Soil Condition ◽  
Electrical Equipment ◽  
Potential Method ◽  
Grounding System ◽  
Grounding Resistance ◽  
Ground Resistance ◽  
Resistance Reduction ◽  
Different Types ◽  
Selection Of ◽  
Electrical Installation

Grounding of electrical installation is primarily concerned with ensuring safety. The main purpose of grounding is to channel the fault current straightly to the earth. To produce a good grounding system, the value of earth resistance must be reduced as low as possible. Otherwise, current may flows through to those who touch the damage electrical equipment instead of flowing through grounding system. In this project, a 3 meter length of copper, galvanized iron and pure steel rod were installed in formatting of grounding system. The installation of the grounding rods was based on the fall of potential method. Both single rod testing and parallel rod testing were performed in this project. A comparison on grounding resistance value for copper rod, steel rod and galvanized iron rod was examined and the selection of the best grounding rod was determined from the experimental data. Result shows that different types of rod will produce different value of resistivity in which depend on installation technique and soil condition.

scholarly journals A Single-Terminal Fault Location Method for HVDC Transmission Lines Based on a Hybrid Deep Network

Electronics ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 255
Author(s):  
Lei Wang ◽  
Yigang He ◽  
Lie Li
Keyword(s):  
Deep Learning ◽  
Transmission Lines ◽  
Fault Location ◽  
Short Term Memory ◽  
Engineering Application ◽  
Energy Operator ◽  
Sampling Frequency ◽  
Learning Technology ◽  
Long Distance ◽  
Hvdc Transmission

High voltage direct current (HVDC) transmission systems play an increasingly important role in long-distance power transmission. Realizing accurate and timely fault location of transmission lines is extremely important for the safe operation of power systems. With the development of modern data acquisition and deep learning technology, deep learning methods have the feasibility of engineering application in fault location. The traditional single-terminal traveling wave method is used for fault location in HVDC systems. However, many challenges exist when a high impedance fault occurs including high sampling frequency dependence and difficulty to determine wave velocity and identify wave heads. In order to resolve these problems, this work proposed a deep hybrid convolutional neural network (CNN) and long short-term memory (LSTM) network model for single-terminal fault location of an HVDC system containing mixed cables and overhead line segments. Simultaneously, a variational mode decomposition–Teager energy operator is used in feature engineering to improve the effect of model training. 2D-CNN was employed as a classifier to identify fault segments, and LSTM as a regressor integrated the fault segment information of the classifier to achieve precise fault location. The experimental results demonstrate that the proposed method has high accuracy of fault location, with the effects of fault types, noise, sampling frequency, and different HVDC topologies in consideration.

scholarly journals Variation of Low-Frequency Time-Code Signal Field Strength during the Annular Solar Eclipse on 21 June 2020: Observation and Analysis

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1216
Author(s):  
Xin Wang ◽  
Bo Li ◽  
Fan Zhao ◽  
Xinyu Luo ◽  
Luxi Huang ◽  
...  
Keyword(s):  
Field Strength ◽  
Solar Eclipse ◽  
Low Frequency ◽  
Signal Propagation ◽  
Normal Operation ◽  
Time Code ◽  
Long Distance ◽  
Time Service ◽  
Annular Solar Eclipse ◽  
Signal Field

Due to the occlusion of the moon, an annular solar eclipse will have an effect on the ionosphere above the earth. The change of the ionosphere, for the low-frequency time-code signal that relies on it as a reflection medium for long-distance propagation, the signal field strength, and other parameters will also produce corresponding changes, which will affect the normal operation of the low-frequency time-code time service system. This paper selects the solar eclipse that occurred in China on 21 June 2020, and uses the existing measurement equipment to carry out experimental research on the low-frequency time-code signal. We measured and analyzed the signal field strength from 20 June 2020 to 23 June 2020, and combined solar activity data, ionospheric data, and geomagnetic data, and attempted to explore the reasons and rules of the change of signal parameters. The results showed that the field strength of the low-frequency time-code signal changed dramatically within a short time period, the max growth value can reach up to 17 dBμV/m and the variation trend yielded ‘three mutations’. This change in signal field strength is probably due to the occurrence of a solar eclipse that has an effect on the ionosphere. When the signal propagation conditions change, the signal strength will also change accordingly.

scholarly journals Prevalence of ACSL (rs6552828) polymorphism among runners

2019 ◽  
Vol 24 ◽  
pp. 121-128
Author(s):  
Sigal Ben-Zaken ◽  
Yoav Meckel ◽  
Dan Nemet ◽  
Alon Eliakim
Keyword(s):  
Single Nucleotide Polymorphism ◽  
Genetic Basis ◽  
Maximal Oxygen Consumption ◽  
Professional Athletes ◽  
Distance Runners ◽  
Nucleotide Polymorphism ◽  
Long Distance ◽  
Single Nucleotide ◽  
The Common

The ACSL A/G polymorphism is associated with endurance trainability. Previous studies have demonstrated that homozygotes of the minor AA allele had a reduced maximal oxygen consumption response to training compared to the common GG allele homozygotes, and that the ACSL A/G single nucleotide polymorphism explained 6.1% of the variance in the VO2max response to endurance training. The contribution of ACSL single nucleotide polymorphism to endurance trainability was shown in nonathletes, however, its potential role in professional athletes is not clear. Moreover, the genetic basis to anaerobic trainability is even less studied. Therefore, the aim of the present study was to examine the prevalence of ACSL single nucleotide polymorphism among professional Israeli long distance runners (n=59), middle distance runners (n=31), sprinters and jumpers (n=48) and non-athletic controls (n=60). The main finding of the present study was that the ACSL1 AA genotype, previously shown to be associated with reduced endurance trainability, was not higher among sprinters and jumpers (15%) compared to middle- (16%) and long-distance runners (15%). This suggests that in contrast to previous studies indicating that the ACSL1 single nucleotide polymorphism may influence endurance trainability among non-athletic individuals, the role of this polymorphism among professional athletes is still not clear.

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