Effective Length Calculation of the Horizontal Buried Grounding Electrode Using Theory of Multi-Conductor Transmission Line

Abstract

The effective length of the grounding rod, as well as the effective surface area of ​​the grounding rod, is a concept related to the dynamic characteristics of the grounding rod. It has been experimentally determined that only a part of the length of a horizontally placed grounding rod, starting from the point of lightning current entry, effectively affects the value of the impulse impedance. There are several definitions of the effective length of a horizontally placed grounding rod. However, all of these definitions boil down to the selection of criteria for calculating the length of the grounding rod at which there is no further change or decrease in the value of the impulse impedance. When the length of the grounding rod exceeds a certain value, a further increase in the length of the grounding rod has a very small impact on the maximum value of the overvoltage and thus on the value of the impulse impedance. The paper will present the calculation of the effective length of a grounding rod buried horizontally in the ground. As a basis for calculating the effective length of a horizontally buried grounding rod, an improved multi-wire line model will be used to solve the problem of electromagnetic wave propagation using the finite element method. The results obtained in this way will be compared with empirical formulas found in the literature, which are based on experimentally obtained results.

Ivica Jurić-Grgić

Full Professor | Department of Theoretical Electrical Engineering and Modelling

Researcher and full professor at the Faculty of Electrical Engineering, Mechanical Engineering, and Naval Architecture in Split. His research focuses on numerical modeling of electromagnetic transients in power systems, with particular emphasis on the development of advanced numerical methods for analyzing electromagnetic transients in multi-conductor transmission lines. His work includes the application of finite element techniques for transient stability analysis of power systems, as well as the enhancement of models for harmonic and transient analysis of grounding systems.