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

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 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

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

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

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

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

Thermal-hydraulic analysis of alternative cable-in-conduit conductors for the European DEMO hybrid central solenoid

Kamil Sedlák, Nikolay Bykovskiy, Roberto Guarino

A hybrid design of the Central Solenoid is under study within the conceptual design phase of the European DEMO fusion reactor. It is based on HTS conductors in the innermost high-field layers, and Nb3Sn and NbTi conductors for field values below 15 T. Sinc ...

2022

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

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

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

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

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

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

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

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

Test and lower bound modeling of keyed shear connections in RC shear walls

Aurelio Muttoni, Cao Linh Hoang, Jesper Harrild Sorensen

This paper presents an investigation into the ultimate behavior of a recently developed design for keyed shear connections. The influence of the key depth on the failure mode and ductility of the connection has been studied by push-off tests. The tests sho ...

Engineering Structures2018

Insulation effect on thermal stability of Coated Conductors wires in liquid nitrogen

Bertrand Dutoit, Bertrand Dutoit

Superconducting wires are not perfectly homogeneous in term of critical current as well as stabilization. In resistive fault current limiter applications this could lead to hot spots if the fault current is only slightly above the nominal current of the de ...

Iop Publishing Ltd2017

An Improved Approach for the Calculation of the Transient Ground Resistance Matrix of Multiconductor Lines

Farhad Rachidi-Haeri

The general integral expressions for the elements of the ground impedance matrix do not have an analytical inverse transform in the time domain. Therefore, the ground transient resistance of a multiconductor line is commonly evaluated in the time domain by ...

Ieee-Inst Electrical Electronics Engineers Inc2016

Contribution to the study of the vulnerability of critical systems to Intentional Electromagnetic Interference (IEMI)

Nicolas Mora Parra

The progress of high power electromagnetic (HPEM) sources during the late 1990s raised the concern in the electromagnetic compatibility (EMC) community that they could be deployed for criminal purposes to interfere with the operation of modern electronic s ...

EPFL2016

Experimental Characterization of the Response of an Electrical and Communication Raceway to IEMI

Farhad Rachidi-Haeri, Marcos Rubinstein, Nicolas Mora Parra

This paper reports the results of two experimental campaigns aimed at studying the high-frequency response of a raceway containing low voltage power, telephone, and Ethernet cables, to external electromagnetic field illumination. The raceway was tested aga ...

Institute of Electrical and Electronics Engineers2016