Effect of Non-Homogeneous Soil Characteristics on Substation Grounding-Grid Performances: A Review

Abstract

Designing an effective grounding system for AC substations needs predetermination of ground resistance and ground potential distribution caused by fault current’s presence in the ground. Therefore, it is necessary to have a suitable grounding grid structure in the soil properties in which the grid is buried. Though the soil composition where the grounding grid is located is typically non-homogeneous, the soil is often presumed to be homogeneous due to the complexities of grounding system analysis in non-homogeneous soil. This assumption will lead to inaccuracies in the computation of ground resistance and ground potentials. Although extensive research has been done on non-homogeneous soil structure, comprehensive literature on grounding system performance in non-homogeneous soil is yet to be reviewed. Thus, this paper reviews the effect of non-homogeneous soil on the grounding system, with different soil characteristics in horizontal and vertical two-layer soil structure and the horizontal three-layer soil structure. In addition, the effect of design parameters on the grounding performance in non-homogeneous soil conditions for non-transient fault conditions is also studied. The significance of this study is that it provides a comprehensive review of grounding performance as grounding design changes and their effects as soil layers and their corresponding features change. This knowledge will be useful in developing safe grounding designs in non-homogeneous soil.

Perancangan Sistem Pentanahan Pada Laboratorium Terpadu Fakultas Teknik Universitas Bengkulu Dengan Metode Two-Layer Soil Vertical Rod Configuration

“…Analisis menggunakan metode Two-layer Soil Vertical Rod Configuration ini mengetahui sifat tanah dalam suatu rangkaian pentanahan baik itu resistif, induktif maupun kapasitif [10]. Pengujian dilakukan dengan mengubahubah besaran frekuensi yang bertujuan untuk mengukur respon sistem pentanahan terhadap gangguan berfrekuensi tinggi, seperti petir atau gangguan lainnya yang mungkin menyebabkan efek elektromagnetik berfrekuensi tinggi [11].…”

Considerations in the design of electrical substations, including the effect of potential gradient on surrounding metallic structures

“…Para evitar la corrosión del CP y de la unión con la malla, deben considerarse sales minerales que se ionizan formando un electrolito sólido con el pH que varía entre 8 y 10. En subestaciones eléctricas en áreas urbanas, se contemplan las partes metálicas que pueden modificar la distribución de potencial eléctrico [36], [37], [38].…”

“…La Tabla 2 resume los trabajos relacionados de las recomendaciones propuestas por varios autores con respecto al diseño de sistemas de puesta a tierra y el comportamiento de los gradientes de potencial que ocurren en las estructuras metálicas circundantes. ✠ ✠ ✠ Permal, 2021 [36] ✠ ✠ Elmashtoly, 2021 [34] ✠ ✠ ✠ Popovic, 2021 [6] ✠ ✠ ✠ Liu, 2021 [41] ✠ ✠ ✠ ✠ Kuchler, 2021 [43] ✠ ✠ ✠ Kavimandan, 2020 [23] ✠ ✠ Tian, 2020 [39] ✠ ✠ DiSilvestre, 2019 [4] ✠ ✠ ✠ ✠ Di Silvestre, 2018 [19] ✠ ✠ Shabangu, 2017 [13] ✠…”