Comparison between utility sub-station and imitative earthing systems when subjected under lightning response

Nor, N. Mohamad; Abdullah, S.; Rajab, R.; Othman, Zulkifli

doi:10.1016/j.ijepes.2012.04.042

Cited by 21 publications

(10 citation statements)

References 19 publications

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“…Std 81 [13], brief guidelines are provided on the measurements at field site using a mobile impulse generator. A number of published papers present the techniques of the equipment used, and describe methods for the impulse tests on grounding systems at field sites [1,3,4,[6][7][8][9][10]14]. However, all of these studies do not really specify the safe distances, at which the results will not be influenced by the electrode under tests.…”

Section: Safe Distances For the Measurements In Ieeementioning

confidence: 99%

“…[9], six ground electrodes were subjected to impulse generator, generating from 50 to 1000 kV, producing current magnitudes up to 20 kA. It was discussed earlier in several studies [7,11] that at higher current magnitudes, faster/lower current rise times are produced, while Harid et al [4] and Mohamad Nor et al [10] had seen that the current rise times are more observable under an influence of configurations at lower current magnitudes (below 300 A). Due to that, when ground electrodes are subjected to higher magnitudes of current, current rise times to indicate the effect of inductance of ground electrode, may hardly be noticed and could be inconsistent in its results, due to high conduction in soil.…”

Section: Introductionmentioning

confidence: 98%

“…Current rise time is defined as the time taken for the current to reach its peak value, while the current discharged time is the time taken for the current to discharge to ground. It was discussed in the field experimental work [4,7,10] that the current rise times are an indication of the presence of inductive effect in the ground electrode, and were studied for a range of configurations, soil resistivity and stress. Harid et al [4] found that the longer the vertical rods and horizontal electrodes, the slower the current rise times were.…”

Section: Introductionmentioning

confidence: 99%

“…Further, it has also been possible that the fault current for distribution systems, can be below 3 kA [12], which shows that there is a need to assess the safety of grounding systems at low magnitudes of impulse current. Despite many publications on the performance of grounding systems under high impulse conditions [1][2][3][4][5][6][7][8][9][10][11], inductive effect in grounding systems has not been well studied, particularly by experimental work. Main reasons for this limitation can be due to unnoticeable delay in current rise times, current discharged times and due to fast response times due to high conduction of ground electrodes under high magnitudes of current.…”

Section: Introductionmentioning

confidence: 99%

“…[4] and Mohamad Nor et al . [10] had seen that the current rise times are more observable under an influence of configurations at lower current magnitudes (below 300 A). Due to that, when ground electrodes are subjected to higher magnitudes of current, current rise times to indicate the effect of inductance of ground electrode, may hardly be noticed and could be inconsistent in its results, due to high conduction in soil.…”

Section: Introductionmentioning

confidence: 99%

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Impulse Characteristics of Ground Electrodes in Low Resistivity Soil

Nor

Abdullah

2023

IEEJ Transactions Elec Engng

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Soil properties have been known to be the factors that influence the ionization process in soil, which cause the impulse impedance, Zimpulse to be lower than that at steady state resistance, RDC. Many studies have established the relationship between the percentage reduction of Zimpulse from RDC in such that the percentage reduction is more pronounced in high resistivity soil, or in high RDC, than that at low resistivity soils. Nevertheless, Zimpulse is not the only parameter in representing the characteristics of soil under high impulse conditions, where from the voltage and current waveforms, the current rise and discharged times can also be established, where more accurate and extensive analysis of the electrical characteristics of ground electrodes subjected to high impulse currents can be achieved. This paper presents the experimental results of four ground electrodes, installed in agricultural land, with soil resistivity, of below 3 Ωm, subjected to high impulse currents, where the parameters of current rise times, Zimpulse and current discharged times were investigated. Two of these ground electrodes are having close RDC values, despite having different electrode's configurations, were also investigated. © 2023 Institute of Electrical Engineer of Japan and Wiley Periodicals LLC.

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Section: Safe Distances For the Measurements In Ieeementioning

confidence: 99%

Section: Introductionmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Impulse Characteristics of Ground Electrodes in Low Resistivity Soil

Nor

Abdullah

2023

IEEJ Transactions Elec Engng

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The effect of soil ionization on transient grounding electrode resistance in non-homogeneous soil conditions

Mokhtari

Abdul‐Malek

Salam

2015

Int. Trans. Electr. Energ. Syst.

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Summary The soil ionization phenomenon effectively reduces the grounding electrode resistance. The existing methods to determine the soil ionization effect on the transient resistance of a grounding electrode are valid only for homogeneous soils. However, most soil structures are non‐homogeneous. Realizing the importance of the issue, this study proposes a hybrid method to incorporate the soil ionization effect on the transient resistance of a grounding electrode located in non‐homogeneous soil condition. The electromagnetic field approach is utilized to compute the ionized soil volume around the electrode to determine the equivalent radius of the electrode. A circuit‐based method of computing the grounding resistance of the electrode in non‐homogeneous soil conditions is proposed based on the per‐unit‐length distributed parameter method. The proposed method is validated by using an electromagnetic field‐based numerical solution for the non‐homogeneity effect of the soil on grounding electrode resistance. Copyright © 2015 John Wiley & Sons, Ltd.

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