Impact of Earthing System Designs and Soil Characteristics on Tower Footing Impedance and Ground Potential Rise: A Modelling Approach for Sustainable Power Operation

Ungku Anisa Ungku Amirulddin,Nur Hazirah Zaini,Nik Hakimi Nik Ali,Mohd Zainal Abidin Ab Kadir,Nur Alia Farina Mohamad Nasir,Muhamad Safwan Abd Rahman,Miszaina Osman,Mohd Solehin Mohd Nasir

doi:10.3390/su13158370

Abstract

Improving a tower earthing system by reducing the impedance is an effective solution to prevent back flashover from occurring and thus maintaining the sustainable operation of power supply. Knowledge of the soil and earthing structure is an important element when designing an earthing system and to determine the parameters of a transmission line (TL). This paper presents the computation of soil structure interpretation based on several earthing designs using current distribution, electromagnetic interference, grounding, and soil structure analysis (CDEGS) software. The results showed that each tower has a multi-layer soil structure and it was also found that the soil resistivity at the surface layer strongly affected the earthing impedance. Subsequently, it was demonstrated that soil structure and the earthing design arrangement are the two parameters that significantly affected the ground potential rise (GPR). This aspect affects the resistance and impulse impedance of a tower and thus influences the performance of the TL system when subjected to lightning strike, which is undoubtedly one of the major culprits of power outages in Malaysia.

Highlights

This paper presented a study of a comparison of footing impedance of different earthing system designs with the influence of soil characteristics on the transmission line towers under lightning behaviour
This paper provided an analysis of the soil structure for each tower under consideration with different soil resistivity values and layers
This study found that Design C represented the best of the design arrangements compared to Design A and Design B with the increasing size of radial, ring, and number of earthing electrodes used, and would help the transmission line tower to be safe by reducing the tower footing impedance

Summary

Introduction

Knowledge of the soil and earthing structure is an important element when designing an earthing system and to determine the parameters of a transmission line (TL). It was demonstrated that soil structure and the earthing design arrangement are the two parameters that significantly affected the ground potential rise (GPR). This aspect affects the resistance and impulse impedance of a tower and influences the performance of the TL system when subjected to lightning strike, which is undoubtedly one of the major culprits of power outages in Malaysia. 1. Introduction with regard to jurisdictional claims in Lightning has continued to be a major cause of disruption giving, rise to line outages in transmission systems.

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Discussion

Conclusion