Performance of Practical Grounding Systems under High Impulse Conditions

Abstract

This paper investigates the factors affecting the impulse characteristics of purposely built grounding systems. We installed 2 m × 2 m grounding systems in four different sites with different soil resistivity values. The effect of impulse polarity on soil characteristics was also investigated for different soil resistivity. A circular ring electrode was used as a return electrode in all four sites. For one of the sites, different configurations of grounding systems were installed to allow the study of the effect of ground electrode configurations on soil characteristics. The aim of this study was to quantify the effects of soil resistivity, impulse polarity, and earth electrode configurations on soil electrical properties under high impulse conditions by field measurements. The new data could be useful in understanding the characteristics of grounding systems in various factors under high impulse conditions. It is hoped that by considering these factors, it can help optimize the design of earthing systems.

Investigations on the Performance of a New Grounding Device with Spike Rods under High Magnitude Current Conditions

“…In a previously published work [18], it was noted that an effect of impulse polarity was seen in high resistivity soil. In this work, a low soil resistivity profile was used.…”

“…publications [2][3][4][5][6][7][8][9][10][18][19][20][21] where the higher the DC earth resistance, the higher the current-dependent characteristics of earth resistance during the passage of high currents.…”

“…Much work [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] has been carried out to characterize practical earthing systems under fast-impulse, high-magnitude current conditions. As generally known, experimental investigations on practical earthing systems under high impulse currents can provide more realistic results on the characteristics of earthing systems under high currents, in comparison to laboratory and computational methods.…”

“…The following year, Bellaschi [3], completed further tests on 12 earth rods, with impulse currents of 400 A to 15.5 kA. There have been a lot more impulse tests [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18], were carried out on practical earthing systems, where tit was found that the 'impulse resistance' values were found to be less than those measured for low voltage, low frequency currents [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. A lot of improvements and suggestions in the impulse test methodology on practical earthing systems can also be seen in the last three decades [1][2][3][4][5][6][7][8][9][10][11][12][13][14]…”

“…A lot of improvements and suggestions in the impulse test methodology on practical earthing systems can also be seen in the last three decades [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. Impulse tests have also been carried out on practical earthing systems considering various factors, namely; earth electrode geometry, soil resistivity, impulse polarity and voltage/current magnitudes [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. For the study of grounding performance with the current magnitudes up to 5 kA, limited studies have been carried out on the effect of the earth electrode's configuration.…”