High current field test of impulse transient characteristics of substation grounding grid

Tong, Xuefang; Xiang, Dong; Tan, Bo

doi:10.1049/joe.2018.8826

Cited by 7 publications

(6 citation statements)

References 2 publications

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“…Panescu summarized the relationship between the amount of electrical charge Q flowing through chest and ventricular fibrillation, proposing the VFT model with the Q as evaluation criterion, the Q can be calculated by Equation (2).…”

Section: Evaluation Methods B Based On Electrical Chargementioning

confidence: 99%

“…The GPR within grounding grid is not equal, leading to ground potential difference (GPD). When grounding experiments with high current are carried out in substation [1][2][3], if staff touches objects with different grounding points at the same time, the GPD will be applied to human body. Current research on GPD mainly focuses on the case of power frequency short circuit, and the calculation method and influencing factors of the GPD within the grounding grid were studied [4][5][6].…”

Section: Introductionmentioning

confidence: 99%

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Hazard evaluation of ground potential difference within grounding grid on personal safety under impulse current

Chun

Wen

Guo

et al. 2021

IET Science Measure & Tech

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Due to the impedance characteristic of conductor, the ground potential rise is different within grounding grid when impulse current is injected. When staff touches objects with different GPR at the same time, the GPD will be applied to human body, leading to potential personal safety problem. The impact of GPD on human body needs to be evaluated. The method of moment was used to calculate the ground potential rise of grounding grid under impulse current. By regarding the human body as a resistance, the current flowing through it because of ground potential difference was obtained. Methods based on current amplitude and electrical charge was used to evaluate personal safety. The effects of injecting current waveform, injecting position, soil resistivity, grounding conductor and grounding grid structure on ground potential difference and safe current threshold were studied. Results show the ground potential difference near injecting point may pose a threat to personal safety. The evaluation method based on electrical charge was recommended. In field test, the injecting point of grounding grid should be far away from corners, and staff should be kept away from the injecting point, so as to mitigate the risk of ground potential difference on personal safety.

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Section: Evaluation Methods B Based On Electrical Chargementioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Hazard evaluation of ground potential difference within grounding grid on personal safety under impulse current

Chun

Wen

Guo

et al. 2021

IET Science Measure & Tech

View full text Add to dashboard Cite

show abstract

“…Thereafter, the currents are injected at the corner of a 20 m x 20 m grid with 5 m x 5 m mesh size. The grid is buried 0.5 m below the surface of the soil with 1000 Ω.m resistivity [82], [104]. Fig.…”

Section: B Effect Of Lightning Current Waveformmentioning

confidence: 99%

Review of Substation Grounding System Behavior Under High Frequency and Transient Faults in Uniform Soil

et al. 2020

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Substations are important parts of electric power systems, and they require well-designed grounding systems. A proper grounding system guarantees the safety of the personnel working in an environment surrounded by grounded equipment from possible electric shock, protects the equipment against unnecessary breakdowns, and conserves the stability of the entire electrical system throughout its operation. Grounding systems developed under power frequency conditions generally react differently under high frequency and transient conditions, such as switching transients and lightning strikes. This work reviews the modeling methods for substation grounding systems and their performance when grounding design parameters change under high frequency and transient fault conditions.

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“…Most substation grounding system safety evaluations and design procedures employ a homogenous soil environment as an input to calculate safety values (grid impedance, step, and touch voltages). However, despite significant studies into grounding behavior in homogenous soil environments (Mokhtari et al, 2016a;Nikolovski et al, 2016;Pavel et al, 2020) and horizontal two-layer soil with varying soil properties such as the upper layer height (Zaini & Ghoneim, 2012) and the soil reflection factors (K) (Gouda et al, 2019;Tong et al, 2019) and varying grid design parameters such as the analysis of single horizontal grounding conductor (de Araujo et al, 2019;Arnautovski-Toseva et al, 2007), the mesh count of a grounding system (Unde & Kushare, 2012), vertical rod length (Anggoro et al, 2018), there is presently no comprehensive study available that assess the grounding behavior in vertical two-layer soil under the impact of design parameters. Furthermore, no simultaneous comparisons or discussions between horizontal and vertical two-layer soil structures are available.…”

Section: Introductionmentioning

confidence: 99%

Assessment of the Grid Safety Values for Substation Grounding Grid Design Parameters in Vertical Two-Layer Soil Structure

Permal¹,

Osman²,

Ariffin³

et al. 2022

JST

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Typically, the impact of the structure of vertically layered soil on the grounding behavior is not considered while designing a substation grounding system. Therefore, it will result in poor grounding designs due to computed inaccurate grid safety values. Besides, no comparative analysis of the grounding design parameters’ impact on the grounding grid systems’ behavior and protection level between vertical and horizontal two-layer soil structures is presently available. Computing and analyzing the grounding behavior of apparent soil resistivity installed in a vertical two-layer soil structure is more challenging than in a horizontal two-layer soil. There are many other parameters to consider, such as the distance ‘a’ between the test electrodes and the angle ‘β’ between the perpendicular line to the soil boundary and the location of the test electrodes. One of the important findings of the assessment shows that the influence of vertically layered soil on grid impedance, step, and touch voltages of a grounding system is insignificant compared to a homogeneous and horizontally layered soil structure. The current flow is affected by an entire grounding grid placed in a specified layer of soil with a specific resistivity for horizontally layered soil. In contrast, soil boundaries separate a grounding grid with various resistivities for vertically layered soil. The outcome of this work is crucial in helping the engineers to understand the behavior of grounding systems in diverse soil conditions and tropical climates.

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High current field test of impulse transient characteristics of substation grounding grid

Cited by 7 publications

References 2 publications

Hazard evaluation of ground potential difference within grounding grid on personal safety under impulse current

Hazard evaluation of ground potential difference within grounding grid on personal safety under impulse current

Review of Substation Grounding System Behavior Under High Frequency and Transient Faults in Uniform Soil

Assessment of the Grid Safety Values for Substation Grounding Grid Design Parameters in Vertical Two-Layer Soil Structure

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