The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
The history of using the earth as an electrical conductor for man-made electricity for the past 270 years is detailed in this paper. In the beginning man-made electricity used the earth; the surface of the terrestrial ball we live on, as a conductor to return the continuous flowing electric current back to the source for 140 years. Edison realized that using the earth as an electrical conductor presented...
Earthing (grounding) cord-connected products creates an equipotential environment for personnel which provides protection against electric shock. The earthing scheme can be functional only, a principal safeguard, a supplementary safeguard, a reinforced safeguard, or a combination of these safeguards. The principal safeguard function returns protective conductor currents to their source and prevents...
The grounding system is extremely important, as it affects the performance of the MTDC system virtually in any possible mode: normal (asymmetrical operation) and abnormal operation (faults), steady-state and dynamic. The objective of this paper is to introduce a simple approach to assess the steady-state post-contingency of multi-Terminal HVDC System and uses it order to illustrate the effects of...
The ongoing international demonstration project (ITER) will be located on a 1200 m long and 800 m wide platform belonging to an even larger site including neighboring areas to the site boundary fences. This whole complex requires a full grounding system which constitutes an electrically large grounding grid. Due to the long construction time, a particular attention is required to deal with safety...
The grounding of electrical systems has become commonplace with little or no thought given to the consequences of indiscriminate grounding. The study of the history of application of electricity with respect to grounding reveals that early procedures that solved the problem at hand resulted in dangerous and hazardous electrical conditions years later. Lessons that Edison learned and have been forgotten...
The following work investigates the risk of electrocution from earth potential rise at transmission substations and nearby third party locations as a result of a power system earth fault. Current earthing standards use a deterministic approach where the risk assessment considers a set of worst-case conditions. However, it is recognised that most of the parameters involved in calculating the earth...
A finite-element mode for the grounding system and soil is built in the software of ANSYS 10.0 to study the performance of grounding systems when considering the soil ionization phenomenon around the grounding system under different soil structures. The calculated results are validated by the simulation results found in the published papers. The performance of the grounding systems when considering...
The paper deals with the clarification of basic terms related to the calculation of the earth potential rise (EPR), transferred potential and earth resistance of the earthing grid. In case of earth fault occurring in a substation, significant fraction of the fault current is flowing in the passive conductors (cable sheath, earth wire) of the lines feeding to the fault. These passive conductors are...
This paper describes the actual problem of inductively interfered pipelines due to traction and short circuit currents of electric railways. At first a brief overview about calculation-formulas and standards is given. Furthermore the most important limits for induced pipe potentials regarding short time- (short circuit currents) and long time interference (normal operation traction currents) of the...
High currents leaked to earth, leads to an electric field, which can be capable of breaking down the dielectric strength of the soil. When this happens, the ionization phenomena takes place, which reduce the grounding system impedance and modify its performance. In this paper, a computational model for transient performance of grounding systems is presented. The model is capable of simulating soil...
The application of high-resistance neutral grounding (HRNG) to medium-voltage systems is one of the least understood and often misapplied methods of system neutral grounding. An HRNG grounded system is the only intention ally grounded neutral grounding method suitable for industrial systems that allows normal operation (no voltage dips, no power surges, no shutdowns, minimal damage) for an indefinite...
In this paper, the authors present a complex calculation algorithm for dimensioning the earthing installation of a substation. There are also presented the own conception calculation program developed in the Visual Basic programming environment, and a comparative analysis of the results got within a case study, after running the program for two variants of fitting out a substation.
We propose here a cost-effective, realistic method for testing the continuity of the grounding grid and for identifying its weak points or discontinuities. The proposed method involves injecting an ac current of ~200 A frequency not 60 Hz or 60 Hz harmonic into a grounding grid. The purpose of the frequency setting is to be able to distinguish the magnetic field produced by the injected current when...
This paper presents the behavior of a grounding mesh in presence of a high-frequency overvoltage transient caused by switch closing in electrical substations and atmospheric discharges. The simulation of the mesh is based on Transmission Line Method (TLM). The output of the simulation is the sum of induced and conducted currents caused by such high-frequency overvoltage input in some spot of the mesh...
In this paper, a new program solution is presented to analyze the electromagnetic field around the grounding grid. In contrast to recently existent procedure based on the “classical” finite element method (FEM), in this new methodology the soil and the air domain of the problem are discretized by the 3-D finite elements and the conductors of the grounding grid are discretized by 1-D finite line elements...
The line lightning performance of the 33 kV distribution line Tanjung Batu - Rompin gives very bad performance during lightning. The lines have bad performance although they were equipped with the line lightning arrester to limit the overvoltages on the phase conductors when lightning strikes the line. There are several cases where the surge arresters were broken and exploded. In this study, the effect...
This paper describes approximate formulas for sending-end voltage and current in a horizontal grounding conductor. The formulas are derived based on the lattice diagram method, and are expressed in time domain. This paper discusses a measurement method for surge impedance of a horizontal grounding conductor using the approximate formulas.
This paper proposes a hybrid Genetic Algorithm-Simulated Annealing technique for optimal design of grounding grids. The technique aims to minimize the installation cost while ensuring the safety of personnel. The safety indices are obtained; using an electromagnetic formulation based on the well-known quasistatic complex image method together with a closed form of Green's function. This method provides...
Solution of chemical substance application for decreasing resistance of grounding system is a current problem that is interested by scientists. In present time, some of companies introduced and used the chemical substances for improving soil and enclosed the software for calculating the experimental grounding resistance but there is not any theoretic document that explains it. This article suggested...
As the proximity of high fault current power lines to residential areas increases, the need for accurate prediction of earth potential rise (EPR) is of crucial importance for both safety and equipment protection. To date, the most accurate methods for predicting EPR are power system modelling software tools, such as EMTP, or recursive methods that use a span by span approach to model a transmission...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.