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Concept

Schéma de liaison à la terre

Publications associées (31)

High-frequency response of a hemispherical grounding electrode

Farhad Rachidi-Haeri, Marcos Rubinstein, Antonio Sunjerga

The lightning discharge current is characterized by a high-frequency spectrum extending from DC to about 10 MHz. The calculation of the grounding impedance is one of the most important aspects of designing lightning protection systems. The search for analy ...

Elsevier2024

Performance Comparison of Cables With Partial Transposition

Pierluigi Bruzzone, Kamil Sedlák, Chiara Frittitta, Federica Demattè

The need of full transposition of the current carrying elements (strands) in large cables is frequently retained as top design criterion for conductors operating in pulsed mode. However, when the transposition error, i.e., the inductance difference among t ...

IEEE Institute of Electrical and Electronics Engineers2024

Assessment of the Feasibility of Applying the Electromagnetic Time Reversal Theory to Locate Defects in Grounding Electrodes

Farhad Rachidi-Haeri, Marcos Rubinstein, Hamidreza Karami, Rafael Silva Alipio

In recent years, the electromagnetic time reversal (EMTR) theory has been successfully applied for locating various sources of disturbances, such as short-circuit faults, in power systems. In this paper, a theoretical analysis of the feasibility of applyin ...

2023

A review of the modeling approaches of the lightning M-component with special attention to their current and electric field characteristics

Farhad Rachidi-Haeri, Marcos Rubinstein, Mohammad Azadifar, Carlo Alberto Nucci

In this paper, we present the characteristics of current, electric fields and modeling approaches of lightning M-component mode of charge transfer. We consider both the classical M-components (occurring after return strokes) and M-component-type ICC (Initi ...

Elsevier2023

Small-argument analytical expressions for the calculation of the ground-return impedance and admittance of underground cables

Rafael Silva Alipio

This paper proposes small-argument approximations for two closed-form equations that were recently derived for the calculation of the ground-return impedance and admittance of underground cables. The proposed expressions are shown to be accurate up to 1 MH ...

Elsevier2023

Assessment of the transmission line theory in the modeling of multiconductor underground cable systems for transient analysis using a full-wave FDTD method

Farhad Rachidi-Haeri, Rafael Silva Alipio, Naiara Figueiredo Duarte

In this paper, a rigorous and independent validation of two different approaches for calculating the ground-return impedance and admittance of multiconductor underground cable systems using the transmission line theory is carried out. Furthermore, analyses ...

Elsevier2023

Influence of a lossy ground on the lightning performance of overhead transmission lines

Farhad Rachidi-Haeri, Rafael Silva Alipio

This paper investigates the impact of incorporating both displacement currents and frequency-dependent soil parameters in the calculation of the ground-return impedance for the determination of the backflashover rate of 138 kV and 230 kV overhead transmiss ...

Elsevier2023

EMC and earthing concept of the ITER EC-system

Damien Fasel, Francisco Sanchez, Ugo Siravo, Jérémie Dubray

Gyrotrons and High Voltage Power Supplies (HVPS) used on electron cyclotron (EC) systems are the source of large electromagnetic interference (EMI). Arcing events inside gyrotrons is the most frequently cited issue, but fast shutdown of a HVPS can produce ...

2023

Interaction of lightning-generated electromagnetic fields with overhead and underground cables

Farhad Rachidi-Haeri, Marcos Rubinstein, Carlo Alberto Nucci

In this chapter, we discussed the TL theory and its application to the problem of lightning electromagnetic field coupling to transmission lines. After a short discussion on the underlying assumptions of the TL theory, we described seemingly different but ...

IET2022

The Geometry and Charge of the Streamer Bursts Generated by Lightning Rods under the Influence of High Electric Fields

Farhad Rachidi-Haeri, Marcos Rubinstein

The streamer bursts generated during the initiation and propagation of leaders play an important role in the creation and maintenance of hot discharge channels in air. The most important parameters related to streamer bursts in this respect are the length ...

2022

Modelling of AC/DC Interactions of Converter-Interfaced Resources for Harmonic Power-Flow Studies in Microgrids

Mario Paolone, Andreas Martin Kettner, Yihui Zuo, Johanna Kristin Maria Becker

Modern power distribution systems experience a large-scale integration of Converter-Interfaced Distributed Energy Resources (CIDERs). As acknowledged by recent literature, the interaction of individual CIDER components and different CIDERs through the grid ...

2022

Portable Multi-Frequency Impedance-Sensing Device for Bacteria Classification in a Flowing Liquid

Sandro Carrara

This paper presents a novel impedance-sensing device and its related microfluidics system developed to characterize the macroscopical properties of bacteria and microparticles. The system is based on a phase-sensitive detector with square-waves excitation ...

IEEE2022

An Effective EMTR-Based High-Impedance Fault Location Method for Transmission Lines

Farhad Rachidi-Haeri

This article summarizes the electromagnetic time-reversal (EMTR) technique for fault location, and further numerically validates its effectiveness when the fault impedance is negligible. In addition, a specific EMTR model considering the fault impedance is ...

2021

Impact of Frequency-Dependent Soil Models on Grounding System Performance for Direct and Indirect Lightning Strikes

Farhad Rachidi-Haeri

The goal of this article is to investigate the effect of frequency-dependent soil models on the performance of grounding electrodes subjected to lightning strikes. Several soil models are examined while accounting for the variation of soil resistivity and ...

2021

Three-Dimensional FDTD-Based Simulation of Induced Surges in Secondary Circuits Owing to Primary-Circuit Surges in Substations

Farhad Rachidi-Haeri, Marcos Rubinstein, Akiyoshi Tatematsu

Currently, plenty of sensitive electronic devices are installed in secondary circuits in substations and power plants. Electronic devices may malfunction and become damaged owing to electromagnetic disturbances caused mainly by lightning surges. To protect ...

2021

Lightning to tall structures: Characterization, Modeling and Protection

Antonio Sunjerga

Lightning physics is highly multidisciplinary, involving areas such as plasma physics, electrical engineering, meteorology, thermodynamics and particle physics. Upward lightning is a special type of lightning initiated from tall structures that has attract ...

EPFL2021

Simulation of High-Frequency Transients in Overhead Lines Including Frequency-Dependent Soil Parameters: an FDTD Aproach

Farhad Rachidi-Haeri, Rafael Silva Alipio

This paper investigates the effect of frequency-dependent soil parameters on the simulation of electromagnetic transients on overhead lines, based on the application of the FDTD method to solve the telegrapher’s equations. The ground return impedance is ca ...

2021

Grounding Resistance of a Hemispheric Electrode Located on the Top of a Finite-Height, Cone-Shaped Mountain

Farhad Rachidi-Haeri, Marcos Rubinstein, Antonio Sunjerga, Hamidreza Karami

In this letter, we present an analytical solution for the resistance of a hemispheric grounding electrode located on the top of a mountain. The mountain is modeled as a truncated cone with a finite height. Recently, a closed-form solution for the grounding ...

2020

Solid State Bus Tie Switch for Shipboard Power Distribution Networks

Drazen Dujic, Gabriele Ulissi

Recent trends in shipboard power distribution network design, such as the transition from AC to DC result in new challenges on the issue of distribution network protection. Devices such as a solid state bus tie switch provide a first line of defence agains ...

2020

Software tools for the lightning performance assessment

Carlo Alberto Nucci

This chapter describes two of the most adopted software tools for the evaluation of the lightning performance of transmission and distribution lines, namely FLASH and LIOV-EMTP (Lightning Induced OverVoltage - ElectroMagnetic Transient Program), together w ...

The Institution of Engineering and Technology IET2020