Impact of Grounding Modeling on Lightning-Induced Voltages Evaluation in Distribution Lines

Abstract

Lightning-induced voltages are one of the main causes of shutdown in distribution lines. In this work, attention is focused on the effects of wideband modeling of electric grounding in the overvoltage calculation along insulator strings due to indirect lightning strikes. This study is done directly in the time-domain with the grounding being represented with an equivalent circuit accounting for its dynamics. Results show that the adoption of commonly adopted simplified grounding models, such as low-frequency resistance, may lead to an underestimation of the overvoltage. According to the results, differences in the order of 25% can be found in some studied cases.

Power Distribution Systems’ Vulnerability by Regions Caused by Electrical Discharges

“…On the other hand, indirect events, whose frequency is higher, are classified as occurring in regions where the power grid is close to the ground. These events are critical for distribution systems since they are characterized by a low critical flashover voltage [29].…”

Transient Analysis of Multiphase Transmission Lines Located above Frequency-Dependent Soils

“…Lightning is one of the primary sources of outages in electrical power systems due to the back flashover mechanism and other insulation failures that can occur in several pieces of equipment [34]. In this context, lately, several authors had worked on the lightning performance of overhead multiphase transmission lines [22,44,45], wind turbines [43,46] and renewable-based hybrid systems [47,48].…”

Lightning Modeling and Its Effects on Electric Infrastructures

“…In order to solve this issue, in principle, a Full-Maxwell simulation is required, leading to high computational costs. The authors of [3] addressed this problem by introducing an equivalent circuit which takes into account all the details of the grounding grid and computing the enhancement of lightning-induced voltage compared to the traditional case [10].…”

“…The contributions to this Special Issue mainly focused on modeling lightning activity, investigating physical causes, and discussing and testing mathematical models for the electromagnetic fields associated with lighting phenomena. In this framework, two main topics have been presented by the authors: (1) the interaction of lightning phenomena with electrical infrastructures such as wind turbines [1] and overhead lines [2][3][4]; and (2) the computation of lightning electromagnetic fields in the case of particular configuration, as the one presented in [5], considering a negatively charged artificial thunderstorm, in [6], considering a complex terrain with arbitrary topography, and in [7], where the ground is simplified and considered a Perfect Electric Conductor.…”