Farhad Rachidi-Haeri

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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 ...

A frequency-domain method is proposed for the transient analysis of grounding systems with ionized soil. The method involves two stages. First, the grounding system is transformed into a nonlinear equivalent circuit, in which the frequency-domain circuit p ...

In this paper, we present a review of theoretical methods to compute lightning induced currents and voltages on buried cables. The evaluation of such induced disturbances requires the calculation of the electric field produced by lightning along the cable ...

Time-domain solutions of Maxwell’s equations in homogeneous and isotropic media are paramount to studying transient or broadband phenomena. However, analytical solutions are generally unavailable for practical applications, while numerical solutions are co ...

The study explores the characteristics of upward negative stepped leader pulses recorded at the Säntis Tower in Switzerland. Analysis of simultaneous channel-base current and 14.7-km vertical electric field data revealed two distinct types of pulses associated with upward negative stepped leaders [2]. Category A pulses were characterized by bipolar electric field signatures with initial positive half-cycles, correlated with negative unipolar current pulses. The E-field pulses had an average duration of 23.7

In this paper, we present a performance analysis of the European Cooperation for Lightning Detection (EUCLID) lightning detection network using data obtained on lightning currents measured at the Santis Tower (located in northeastern of Switzerland) from J ...

In electromagnetic models, the return-stroke channel is represented as an antenna excited at its base by either a voltage or a current source. To adjust the speed of the current pulse propagating in the channel to available optical observations, different ...

The evaluation of electromagnetic transients in overhead power lines due to nearby lightning return strokes requires accurate models for the calculation of both the incident lightning electromagnetic pulse ( LEMP) and the effects of coupling of this field ...

In this paper, we discuss two issues related to the measurement and calculation of the horizontal electric fields from lightning. On the one hand, there is an inherent difficulty inmeasuring the horizontal electric field component from lightning because of ...

In this paper we present and discuss measurements of electric (vertical and radial) and magnetic fields from leaders and return strokes associated with lightning strikes to the 100 m tall Gaisberg tower in Austria obtained in 2007 and 2008. The fields were ...

In this paper, an inequality satisfied by the vacuum energy density of the universe is derived using an indirect and heuristic procedure. The derivation is based on a proposed thought experiment, according to which an electron is accelerated to a constant ...

One of the characteristic features of the electromagnetic fields radiated by lightning is the far-field inversion of polarity with a zero-crossing occurring in the tens of microseconds range. This feature has been used in several studies to test the abilit ...

The cascaded transmission line theory of Paul and McKnight is used in this paper to predict near-end crosstalk (NEXT) and far-end crosstalk (FEXT) in a bundle of twisted wire pairs. The approach is validated using the CST Cable Studio commercial software a ...

A correct representation of the lightning current is crucial when the electromagnetic field radiated to a point of interest has to be computed. Based on the engineering models of Transmission Line type, such representation involves the knowledge of the ret ...

In this paper, we analyze the propagation effects on lightning-radiated electromagnetic fields over mountainous terrain by using a three-dimensional (3-D) finite difference time domain (FDTD) method. We also discuss the time delay error in the time-of-arri ...

In this paper, we investigate the reasons why some return stroke models do not reproduce one of the characteristic features of the electromagnetic fields radiated by lightning, namely the far-field inversion of polarity with a zero crossing occurring in th ...

The localization of partial discharges (PD) is important to monitor the conditioning of high voltage insulator materials. One of the key components in power grids is the high power transformer. Localization of PDs in these pieces of equipment can increase ...

This paper presents a comparison of machine learning (ML) methods used for three-dimensional localization of partial discharges (PD) in a power transformer tank. The study examines ML and deep learning (DL) methods, ranging from support vector machines (SV ...

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 ...

The term “mixed mode of charge transfer to ground for initial continuous current (ICC) pulses” in the context of upward lightning flashes was first proposed by Zhou et al. 2011 [1] to describe fast pulses, distinct from the classical M-component mode of charge transfer, superposed on the slowly varying initial-stage current of upward negative flashes they observed at the Gaisberg Tower in Austria. The pulses in question were associated with leader/return-stroke processes occurring in decayed or newly create

Farhad Rachidi-Haeri

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

Frequency-domain analysis of ground electrodes buried in an ionized soil when subjected to surge currents: A MoM–AOM approach

Lightning induced disturbances in buried cables - Part I: Theory

The time-domain Cartesian multipole expansion of electromagnetic fields

Comparing Upward Negative Stepped Leader and Preliminary Breakdown Pulses

Evaluation of the performance characteristics of the European Lightning Detection Network EUCLID in the Alps region for upward negative flashes using direct measurements at the instrumented Säntis Tower

On Practical Implementation of Electromagnetic Models of Lightning Return-Strokes

Lightning Electromagnetic Field Coupling to Overhead Lines: Theory, Numerical Simulations and Experimental Validation

On the Measurement and Calculation of Horizontal Electric Fields From Lightning

Lightning Electromagnetic Fields at Very Close Distances Associated with Lightning Strikes to the Gaisberg Tower

Heuristic Estimation of the Vacuum Energy Density of the Universe: Part I—Analysis Based on Time Domain Electromagnetic Radiation

Analytical Expressions for Zero-Crossing Times in Lightning Return-Stroke Engineering Models

Application of the Cascaded Transmission Line Theory of Paul and McKnight to the Evaluation of NEXT and FEXT in Twisted Wire Pair Bundles

On the reconstruction of the attenuation function of a return-stroke current from the Fourier Transform of finite-duration measurements

Analysis of lightning electromagnetic field propagation in mountainous terrain and its effects on ToA-based lightning location systems

Why do some lightning return stroke models not reproduce the far-field zero crossing?

Partial discharge localization in power transformers using acoustic time reversal

Partial discharge localization in power transformer tanks using machine learning methods

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

Mixed Mode of Charge Transfer During an Upward Positive Flash at Säntis Tower