Publications related to Undergrounding

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

Exact Expressions for Lightning Electromagnetic Fields: Application to the Rusck Field-To-Transmission Line Coupling Model

Farhad Rachidi-Haeri, Marcos Rubinstein

An exact analytical expression for the electric field of the return stroke as excited by a propagating step current source is derived in this paper. This expression could be advantageously used to evaluate the disturbances caused by lightning on overhead l ...

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

Tower-foot grounding model for EMT programs based on transmission line theory and Marti's model

Rafael Silva Alipio

This paper proposes a tower-foot grounding system model compatible with EMT programs which might be useful for the simulation of lightning transients in overhead lines. The proposed model is based on the solution of the telegrapher's equations and the appl ...

Elsevier2023

Performance of the Cable-in-Conduit Conductors for Super-X Test Facility

Kamil Sedlák

Following the conceptual design, the engineering design of the dc magnet and cable-in-conduit conductor (CICC) for the Super-X test facility has been done in 2021. Totally three types of conductors with different structures were designed for the three pair ...

IEEE Institute of Electrical and Electronics Engineers2023

A Lightweight Device for Energy Harvesting from Power Lines with a Fixed-Wing UAV

Dario Floreano, William John Stewart

Modern UAVs (Unmanned Aerial Vehicles) suffer from restrictions in flight range and time due to battery capacity limitations. One way to overcome these limitations is to harvest energy from overhead power lines. A growing body of scientific literature has ...

IEEE2022

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

Field-to-Transmission Line Coupling Models With Special Attention to the Cooray–Rubinstein Approximation

Marcos Rubinstein

There are three equivalent procedures to evaluate the voltages induced by lightning on power lines, namely, the Agrawal–Price–Gurbaxani model, the Taylor–Satterwhite–Harrison model, and the Rachidi model. The Cooray–Rubinstein approximation is a procedure ...

2021

An Efficient Methodology for the Evaluation of the Lightning Performance of Overhead Lines

Farhad Rachidi-Haeri

This article proposes a method for the derivation of a formula that links the maximum lightning-induced-overvoltage occurring on an overhead distribution line with the variables that characterize the lightning return stroke, such as the peak current, front ...

2021

Lightning-Induced Voltages on Overhead Distribution Lines Computed through Analytical Expressions for the Electromagnetic Fields

Farhad Rachidi-Haeri, Marcos Rubinstein

The evaluation of lightning ElectroMagnetic (EM) fields represents the most cumbersome part of the lightning-induced voltages computation process. Their evaluation is usually performed through a numerical routine or with simplified analytical expressions, ...

2021

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

Evaluation of Site Errors in LLS Magnetic Direction Finding Caused by Large Hills Using the 3D‐FDTD Technique

Farhad Rachidi-Haeri, Wolfgang Schulz, Hannes Kohlmann

Angle and amplitude estimation errors in magnetic direction finding, called site errors, are important sensor-specific errors in lightning location systems (LLS). They are known to be caused by nearby cables and overhead lines due to induced currents. Due ...

2021

Electromagnetic Time Reversal Method to Locate Partial Discharges in Power Networks Using 1D TLM Modelling

Farhad Rachidi-Haeri, Marcos Rubinstein

This letter sets out to describe the first results of the design process that will lead to a new on-line partial discharge location method based on Electromagnetic Time Reversal theory and using the Transmission Line-Matrix method. A description of the bas ...

2021

Time reversal applied to fault location in power networks: Pilot test results and analyses

Mario Paolone, Zhaoyang Wang, Reza Razzaghi

This paper presents the results of a pilot test performed on a real medium voltage distribution network in Switzerland with the aim of assessing the performance of a fault location system relying on the Electromagnetic Time Reversal (EMTR) method. To the b ...

2020

Hierarchical Control in Islanded DC Microgrids With Flexible Structures

Giancarlo Ferrari Trecate, Pulkit Nahata, Alessio La Bella

Hierarchical architectures stacking primary, secondary, and tertiary layers are widely employed for the operation and control of islanded dc microgrids (dcmGs) composed of distribution generation units (DGUs), loads, and power lines. However, a comprehensi ...

2020

A scalable, line-independent control design algorithm for voltage and frequency stabilization in AC islanded microgrids

Giancarlo Ferrari Trecate, Michele Tucci

We propose a decentralized control synthesis procedure for stabilizing voltage and frequency in AC Islanded microGrids (ImGs) composed of Distributed Generation Units (DGUs) and loads interconnected through power lines. The presented approach enables Plug- ...

2020

On the Stability of FDTD-Based Numerical Codes to Evaluate Lightning-Induced Overvoltages in Overhead Transmission Lines

Farhad Rachidi-Haeri

One of the main issues that has to be faced when evaluating lightning-induced overvoltages on a realistic network configuration is to implement the algorithm that solves the field-to-line coupling problem into an electromagnetic simulator that is able to r ...

2020

Machine Learning-Based Lightning Localization Algorithm Using Lightning-Induced Voltages on Transmission Lines

Farhad Rachidi-Haeri, Marcos Rubinstein, Mohammad Azadifar, Amirhossein Mostajabi, Hamidreza Karami

In this article, we present a machine learning-based method to locate lightning flashes using calculations of lightning induced voltages on a transmission line. The proposed approach takes advantage of the preinstalled voltage measurement systems on power ...

2020

MMC-based conversion for MVDC applications

Stefan Milovanovic

In recent years, DC grids have gained momentum due to the advantages they display over their AC counterparts. For instance, high voltage DC grids have been established as the most prominent solution in the underwater power transmission or interconnection o ...

EPFL2020