Performance of Practical Grounding Systems under High Impulse Conditions

Muhd Reffin,Normiza Nor,Syarifah Abdullah,Nurul Ahmad

doi:10.3390/en11113187

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.

Highlights

Extensive investigations on the impulse characteristics of grounding systems have been presented in many research studies [1,2,3,4,5,6,7,8,9,10]
Some improvement can be made on the grounding systems installed in soils with high resistivity in the regions that are prone to negative lightning strikes, since this paper revealed that the effect of impulse polarity is more likely significant for grounding systems installed in high resistivity soil
Impulse tests with different current magnitudes were conducted on 4-rod ground electrodes installed at four different sites, with different soil resistivity

Summary

Introduction

Extensive investigations on the impulse characteristics of grounding systems have been presented in many research studies [1,2,3,4,5,6,7,8,9,10]. Some research studies [1,2,3,4,5,6,7,8,9,10] have investigated the factors affecting the discharge processes in soil that take place when the earth electrode is subjected under fast impulses; soil resistivity, earth electrode configurations, impulse polarity, current response time and soil layers. Most of these studies [9,10] were performed using a laboratory approach under controlled conditions. The studies [9,10] are useful in providing a better understanding of the conduction mechanisms in soil under fast impulse currents, and determining the factors affecting the soil characteristics under high impulse currents more accurately

Objectives

Results

Conclusion