Analysis of the performance of grounding grids buried in heterogeneous soil under impulse current (original) (raw)
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COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, 2020
Purpose The purpose of this paper is to investigate the simultaneous effects of ionization and dispersion of soil on the impulse behavior of grounding electrodes under first and subsequent stroke currents. Design/methodology/approach A recently introduced technique called improved multi-conductor transmission line (MTL) is simplified for grounding electrodes buried in both-affected soils. Findings The simulation results show that including the two effects simultaneously in highly resistive soils under high-valued subsequent stroke current is recommended. Otherwise, simultaneous effects can be disregard. Originality/value To the best of the authors’ knowledge, there is no research on sensitivity analyses for the simultaneous inclusion of the two effects on the effective length and the induced voltage on the soil surface. To this end, the simplified MTL is applied to the grounding electrodes. The simulation results show that the computational efficiency in comparison with previous met...
Transient Behaviour of a Horizontal Grounding Grid Under Impulse Current
In this paper the authors attempt to study the behaviour of grounding grids under impulse lightning current. For the simulation of their transient behaviour, the program PSCAD/EMTDC (Power Systems Computer Aided Design / ElectroMagnetic Transients for DC) has been used. The mathematical model elaborated for the PSCAD/EMTDC is characterised by a circuital approach, which is based on the π nominal circuit. The inductance and the capacity of the equivalent circuit have been programmed in Pascal code. The resistance and the conductance have been estimated using formulas given in the relevant literature. Different simulations have been carried out altering the shape of the impulse current. Numerical results are presented for two extreme cases: in the first case the current is injected in the centre of the grid and in the second one it is injected in one corner of the grid. The aim of this work is to verify the applicability of this approach in the behaviour analysis of grounding systems ...
Transient lightning response from a grounding grid buried in horizontal multilayered earth
2014 International Conference on Power System Technology, 2014
The present study developed a mathematical model, which was combined with the Fast Fourier Transform (FFT), to facilitate the accurate computation of the transient lightning response from a grounding grid buried in horizontal multilayered earth. This approach is a hybrid of Galerkin's method of moment and the conventional nodal analysis method. The dynamic state complex image method and the closed form of Green's function for a dipole and monopole in the horizontal multilayered earth model were introduced into this model to accelerate the calculation of the mutual impedance and induction coefficients. Analytical formulae were developed for the mutual induction and impedance coefficients to further accelerate the calculation. With the inverse FFT, the model can be used to study the transient lightning response of a grounding grid.
Factors affecting transient response of grounding grid systems
2008 5th International Multi-Conference on Systems, Signals and Devices, 2008
Grounding system behavior under transient condition is investigated. Transmission line approach has been chosen to simulate the buried grounding system under lightning condition Different models of buried grounding grids have been studied under lightning conditions. Sensitivity analysis of soil parameters and grounding grid dimensions have been studied to understand the effect of each parameter on the performance of grounding systems subjected to lightning.
Experimental investigation of grounding grid impulse characteristics
European Transactions on Electrical Power, 2007
The paper provides a procedure for experimental determination of the grounding grid impulse characteristics. The principles of forming the measuring scheme, disposition and characteristics of the equipment used are described. Some of the numerous experimental results f o r the square-shaped grounding grid are presented. The results have been obtained f o r various shapes, magnitudes and discharge points of the impulse currents and are related to the cases without soil ionization around the grid elements.
The influence of the soil parameters dependence with frequency on impulse grounding behavior
2009
This paper investigates the influence of the soil electrical conductivity and permittivity dependence with frequency in grounding response to lightning currents. Simulated results for soil with frequency variation of its parameters show: i) a significant reduction of the amplitude values of the transient voltages and impulse impedance; ii) an increase of the expected effective length of electrode; iii) a significant reduction of the impulse coefficient with values, in some cases, below unity. These effects are more relevant for high-resistivity soils and are due to the pronounced capacitive effect observed when the soil parameters dependence with frequency is included in simulations.
Behaviour Of A Grounding System Under Impulse Lightning Current
Proceedings of the 6th International Conference on Optimization of Electrical and Electronic Equipments, 1998
This paper deals with the behaviour of a grounding system, under impulse lightning current. The authors have made a large number of experiments in the High Voltage Laboratory of N.T.U.A. and the relevant experimental results were found to agree favorably with those obtained theoretically by using the Electromagnetic Transient Analysis Program (EMTP). Experimental results have been obtained by using variable peak impulse lightning current. The typical waveforms of the injected electric current and the variation of the potential and the impedance upon the time are presented using diagrams which show the compliance between theoretical and experimental data.
IEEE TRANSACTIONS ON ELECTROMAGNETIC COMPATIBILITY, 2023
This article proposes a new time-domain partial element equivalent circuit method mathematical model. The mutual impedance matrix between the potential on the discrete node and the leakage current on the conductor connected around the discrete node is adopted. To reduce the amount of calculation, the matrix equation that minimizes the unknown quantity is derived and adopted. The model can accurately calculate the lightning current distribution and lightning impulse response in a horizontal multilayered soil model considering the soil ionization effect. To improve computational efficiency, the quasi-static complex image method and its closed form of Green's function in the time domain are introduced into the model. Index Terms-Closed form of Green's function, lightning currents, multilayered Earth model, nodal analysis, partialelement equivalent circuit (PEEC) method, quasi-static complex image method in time domain.
Effects of Soil Profile on the Transient Performance of Substation Grounding System
Indonesian Journal of Electrical Engineering and Computer Science
Lightning transient characteristic of the grounding grid is fundamental for optimum performance of lightning protection of a substation. In order to design an appropriate grounding system for such substation, it is important to study its transient characteristics because the high impulse current is significantly different compared to power frequency current. In this paper, substation grounding grid model was developed using CDEGS software to analyze the grid transient performance in terms of ground potential rise (GPR), touch voltage and step voltage when the grounding system is struck by a lightning impulse current. Several parameters, such as lightning current amplitude, feed point and the number of sub-grids, were altered to study their relationship with the transient performance. The maximum transient GPR, touch voltage, and step voltage increase as the lightning current amplitude increase. The maximum transient GPR and step voltage are the highest at the corner of the grounding...
Evaluation of Transient Response of Different Earthing Configurations due to Lightning Impulses
International Journal of Recent Technology and Engineering (IJRTE), 2019
Earthing system is very important in order to protect the electrical equipment as well as the human’s safety against over voltages. The main function of the earthling system is to remove unwanted excessive electrical currents caused by unusual conditions such as fault and lightning or switching over voltages by providing a low resistance path to the earth. Researchers had studied the behaviour of the earthling system to improve its performance for the past few years. There are few factors that influence the performance of the earthling system such as soil resistivity and soil ionization which need to be focused in order to improve the earthling. Thus, this paper evaluates on the factors that affect the behaviour of the earthling system based on simulation works using MATLAB and Safe Grid Software. Some analytical calculations are used to obtain the soil resistivity and resistance as well as the touch and step voltages. The simulation results were validated based on comparison with o...