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

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

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

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

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

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

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

Calculation of the Grounding Resistance of Structures Located on Elevated Terrain

Farhad Rachidi-Haeri, Marcos Rubinstein, Antonio Sunjerga

We present an analysis of the response of a grounding electrode located on the top of a mountain. Specifically, we derive an analytical solution for the low-frequency response of a hemispheric grounding electrode buried on the top of a cone-shaped mountain ...

2019

On the Influence of an Elevated Terrain on the Grounding Resistance of a Vertical Rod

Marcos Rubinstein, Antonio Sunjerga

In this paper, we analyze the grounding resistance of a vertical grounding rod located in an elevated terrain. Tall structures such as wind turbines and mobile phone base stations are often installed in remote and hilly locations to gain more power or to f ...

2019

On the Influence of an Elevated Terrain on the Grounding Resistance of a Vertical Rod

Farhad Rachidi-Haeri, Marcos Rubinstein, Antonio Sunjerga

In this paper, we analyze the grounding resistance of a vertical grounding rod located in an elevated terrain. Tall structures such as wind turbines and mobile phone base stations are often installed in remote and hilly locations to gain more power or to f ...

IEEE2019

Isolated vs. Interconnected Wind Turbine Grounding Systems: Effect on the Harmonic Grounding Impedance, Ground Potential Rise and Step Voltage

Farhad Rachidi-Haeri, Marcos Rubinstein, Antonio Sunjerga, Qi Li

Wind turbines are very vulnerable to lightning strikes due to their height, sharp edges and remote locations often with high soil resistivity. In this paper we present numerical simulations of the impedance of a typical wind turbine grounding geometry. We ...

Elsevier2019

Reduction of a Cone-Shaped Terrain Grounding Resistance by Remote Grounding

Farhad Rachidi-Haeri, Marcos Rubinstein, Antonio Sunjerga

Tall structures such as wind turbines and mobile phone base stations are often installed in remote and hilly locations to gain more power or to have line of sight to end users. Those locations are usually very rocky and characterized by a low-conductivity ...

IEEE2019

Tower and Path-Dependent Voltage Effects on the Measurement of Grounding Impedance for Lightning Studies

Marcos Rubinstein, Keyhan Sheshyekani, Hamidreza Karami, Antonio Sunjerga

We present an analysis aimed at evaluating the effect of the presence of the tower on the measurement of the grounding impedance. The Numerical Electromagnetics Code NEC-4 is used for the full-wave modeling of the structure including the tower and its foot ...

2019

On the representation of thin wires inside lossy dielectric materials for FDTD‐based LEMP simulations

Farhad Rachidi-Haeri, Marcos Rubinstein, Akiyoshi Tatematsu

The finite-difference time-domain method is one of the most widely used numerical electromagnetic computation techniques, and it has become an effective tool for analyzing electromagnetic transient phenomena in three-dimensional structures and grounding sy ...

2019

Transient Impedance of Interconnected Wind Turbine Grounding Systems

Farhad Rachidi-Haeri, Marcos Rubinstein, Antonio Sunjerga, Qi Li

Wind turbines are very vulnerable to lightning because of their height, sharp edges and remote locations often with low soil conductivity. In this paper we present numerical simulations of the impedance of a typical wind turbine grounding geometry. We anal ...

IEEE2018

A Modified Formula for Distance Relaying of Tapped Transmission Lines with Grounded Neutrals

Mario Paolone, Sadegh Azizi

Protection of tapped transmission lines with grounded neutrals has been always a challenging problem, usually resulting in compromise solutions. This type of lines may be protected by pilot relaying requiring dedicated and reliable telecommunication links. ...

2018

Generalized Telegrapher's Equations for Buried Curved Wires

Farhad Rachidi-Haeri, Damir Cavka

The paper deals with the calculation of transient currents and voltages along curved wire structures buried in a lossy ground using the generalized Telegrapher's equations. The influence of a lossy half space is taken into account by the simplified reflect ...

IEEE2018

An experimental field study of the grounding system response of tall wind turbines to impulse surges

Marcos Rubinstein, Nicolas Mora Parra, Antonio Sunjerga

In this work, an experimental investigation of the grounding system behavior of tall wind turbines in both time and frequency domains is presented. Two scenarios were considered: in the first one, measurements were carried out on the grounding system embed ...

Elsevier2018

Mixed-Potential Integral Equation for Full-Wave Modeling of Grounding Systems Buried in a Lossy Multilayer Stratified Ground

Farhad Rachidi-Haeri, Keyhan Sheshyekani, Hamidreza Karami

The paperpresents a comprehensive approach for full-wave modeling of grounding systems buried in a multilayer stratified ground. The dyadic spectral domain Green's function associated with the multilayer stratified ground is first derived. This Green's fun ...

Institute of Electrical and Electronics Engineers2017

Assessing the degradation of compliant electrodes for soft actuators

Samuel Rosset, Herbert Shea, Alexandre Poulin, Christine Anne de Saint-Aubin

We present an automated system to measure the degradation of compliant electrodes used in dielectric elastomer actuators (DEAs) over millions of cycles. Electrodes for DEAs generally experience biaxial linear strains of more than 10%. The decrease in elect ...

American Institute of Physics2017

A Comparison of Frequency-Dependent Soil Models: Application to the Analysis of Grounding Systems

Farhad Rachidi-Haeri, Nicolas Mora Parra, Damir Cavka

We present a review and comparison of different models representing the frequency dependence of the soil electrical parameters (conductivity and permittivity). These models are expressed in terms of curve-fit expressions for the soil conductivity and relat ...

Ieee-Inst Electrical Electronics Engineers Inc2014