Publications associées à Ground and neutral

High-frequency response of a hemispherical grounding electrode

Marcos Rubinstein, Antonio Sunjerga, Farhad Rachidi-Haeri

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

Highly anisotropic carbon fiber electrodes for DEAs and their dynamic non-monotonic conductive properties

Yves Perriard, Stefania Maria Aliki Konstantinidi, Markus Koenigsdorff

A common method for creating compliant electrodes for dielectric elastomer actuators (DEAs) and soft sensors is to incorporate electrically conductive carbon particles into a polymer matrix. However, using unidirectional aligned carbon fibers instead not o ...

Society of Photo-Optical Instrumentation Engineers (SPIE)2024

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

AC loss and electrical resistance of the RW3 diffusion-bonded joint

Vincenzo D'Auria

For the European DEMO fusion reactor, several options of the Toroidal Field (TF) coil design were proposed. The winding of the TF coil option 1 is based on React&Wind (RW), Nb3Sn, graded conductors in order to optimize the amount of superconductor accordin ...

2023

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

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

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

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

Self-consistent Hubbard parameters from density-functional perturbation theory in the ultrasoft and projector-augmented wave formulations

Nicola Marzari, Iurii Timrov, Matteo Cococcioni

The self-consistent evaluation of Hubbard parameters using linear-response theory is crucial for quantitatively predictive calculations based on Hubbard-corrected density-functional theory. Here, we extend a recently introduced approach based on density-fu ...

AMER PHYSICAL SOC2021

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

Moving toward mass-conserving simulations of plasma turbulence and kinetic neutrals in the tokamak boundary with the GBS code

Paolo Ricci

A model for the simulation of the tokamak boundary is described, which is mass-conserving to leading order in rho s / R 0 (where rho s is the ion sound Larmor radius and R-0 is the tokamak major radius at the magnetic axis). The model integrates a three-di ...

2021

Designing Horizontality

Paola Viganò, Tommaso Pietropolli

This paper is divided into three parts. The first introduces a trilogy of concepts and figures of the discourse. The concept of isotropy, as opposed to hierarchy, evokes the same conditions in all directions. The concept of porosity tackles the fluidity an ...

ROUTLEDGE JOURNALS, TAYLOR & FRANCIS LTD2021

Superconductors for power applications: an executable and web application to learn about resistive fault current limiters

Francesco Grilli, Nicolo' Riva, Bertrand Dutoit, Bertrand Dutoit

High-temperature superconductors (HTS) can be superconducting in liquid nitrogen (77 K) at atmospheric pressure, which holds immense promises for our future such as nuclear fusion, compact medical devices and efficient power applications. In a power system ...

2021

Design and Characterization of the Interlayer Joint Between Low-Field Nb3Sn Conductors of a Layer Wound DEMO TF Coil

Pierluigi Bruzzone, Kamil Sedlák, Boris Stepanov, Mithlesh Kumar

In the frame of the conceptual design studies for the Toroidal Field (TF) coils of DEMO, a solution based on a layer-wound magnet, rectangular-shaped Cable-in-Conduit conductors and W&R manufacturing approach, is being developed. The feasibility and perfor ...

IEEE Institute of Electrical and Electronics Engineers2021

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

Marcos Rubinstein, Antonio Sunjerga, Farhad Rachidi-Haeri, 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

Deexcitation Characterization for Power Supply Protection in DC Shipboard Power Systems

Drazen Dujic, Seongil Kim

The deexcitation of a synchronous machine has been used for the protection of the power supply based on a diode rectifier in marine dc power distribution networks. The fault current from the generator can be eliminated with the protection method utilizing ...

IEEE2020

A Generalized Index for Static Voltage Stability of Unbalanced Polyphase Power Systems including Thévenin Equivalents and Polynomial Models

Mario Paolone, Andreas Martin Kettner

This paper proposes a Voltage Stability Index (VSI) suitable for unbalanced polyphase power systems. To this end, the grid is represented by a polyphase multiport network model (i.e., hybrid parameters), and the aggregate behavior of the devices in each no ...

IEEE Institute of Electrical and Electronics Engineers2019

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

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

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

Calculation of the Grounding Resistance of Structures Located on Elevated Terrain

Marcos Rubinstein, Antonio Sunjerga, Farhad Rachidi-Haeri

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