Alternating point current source in multilayer medium

Abstract

Grounding conductors of electrical installations are an important part of the power system. Most mathematical models for modeling grid grounding conductors are based on the assumption that the current is direct. This assumption is used because harmonic current, as well as lightning current, require more complex mathematical models. One of the problems in creating new mathematical models that are able to take into account harmonic current or impulse current is taking into account the influence of heterogeneity of the medium. In this diploma thesis, an approximation based on the mapping of a point source of harmonic current on the boundaries of a horizontally stacked multilayer medium, consisting of air and at most three layers of soil, is developed. The presented mapping method is approximate because the potential retardation is neglected. In the paper, analytical expressions for the potential distribution in a single layer of a multilayer medium when the point current source is located: a) in the air, b) in the first layer of soil, c) in the second layer of soil are derived. The potential retardation can be partially taken into account by subsequently considering each source and its images, obtained by the imaging method, because the source and its images represent a set of point sources in a homogeneous and unbounded medium that has the characteristics of the considered layer.

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.