Concept

Effet de peau

Publications associées (31)

Understanding and mitigating resistive losses in fired passivating contacts: role of the interfaces and optimization of the thermal budget

Christophe Ballif, Aïcha Hessler-Wyser, Franz-Josef Haug, Audrey Marie Isabelle Morisset, Sofia Libraro, Julien Hurni, Luca Massimiliano Antognini, Ezgi Genç

This work presents a study of p-type passivating contacts based on SiCx formed via a rapid thermal processing (RTP) step, using conditions compatible with the firing used to sinter screen-printed metallization pastes in industry. The contributions of the t ...

Elsevier2023

Modeling, Optimization and Design of High Power Medium Frequency Transformers

Nikolina Djekanovic

Nowadays, direct current (DC) technology is increasing its presence in alternating current (AC) power systems. This trend is enabled by the progress in energy conversion through semiconductor devices and power electronics. Therefore, it is possible to imag ...

EPFL2023

First developments towards producing inductive magnetic sensors using state-of-the-art photolithography techniques

Duccio Testa, Marcus Cemes, Ambrine Douhane

Inductive magnetic sensors are needed for tokamak operation to provide the low-frequency (LF) measurements leading to the equilibrium reconstruction and to monitor the higher frequency (HF) instabilities; the HF magnetic sensors are often also used as a ba ...

2023

Runaway dynamics in tokamak disruptions with current relaxation

The safe operation of tokamak reactors requires a reliable modelling capability of disruptions, and in particular the spatio-temporal dynamics of associated runaway electron currents. In a disruption, instabilities can break up magnetic surfaces into chaot ...

Cambridge University Press2022

Design Optimization of a MW-level Medium Frequency Transformer

Drazen Dujic, Nikolina Djekanovic

Nowadays, with the increased interest in applications dealing with high-power medium-voltage conversion, there is a strong need to master the design of medium-frequency transformers, which are one of the key components of modern DC transformers. The paper ...

2022

Effect of Local Defects on HTS Fusion Magnets Performance

Local defects in the manufacturing of high temperature superconducting cable-in-conduit conductors are known to be present at different stages of the conductor production. The impact of such defects on the performance of one module of the hybrid option of ...

IEEE Institute of Electrical and Electronics Engineers2022

Direct measurement of the triple spin flip rate in dynamic nuclear polarization

Andrea Capozzi

A previous study of the effect of Gadolinium doping on the dynamic polarization (DNP) of C-13 using trityls showed that the rate at which the polarization builds up is almost independent of the Gadolinium concentration, while the electron spin-lattice rela ...

Academic Press Inc - Elsevier Science2021

Wearable and Continuous Prediction of Passage of Time Perception for Monitoring Mental Health

David Atienza Alonso, Lara Orlandic, Adriana Arza Valdes

A person’s passage of time perception (POTP) is strongly linked to their mental state and stress response, and can therefore provide an easily quantifiable means of continuous mental health monitoring. In this work, we develop a custom experiment and Machi ...

2021

Continuously-fed density currents over impermeable and porous substrates

Sara Venuleo

Gravity currents are buoyancy-driven flows having a significant impact on the environment and human life. They can be observed in a vast range of natural and anthropogenic scenarios, such as seawater and freshwater, the atmosphere, or industrial processes. ...

EPFL2020

Silicon Photonic MEMS Phase-Shifter

Niels Quack, Hamed Sattari, Teodoro Graziosi, Marcell Kristof Kiss

We present a design for an analog phase shifter based on Silicon Photonic MEMS technology. The operation principle is based on a two-step parallel plate electrostatic actuation mechanism to bring a vertically movable suspended tapered waveguide in a first ...

2019

Very-High-Speed Miniaturized Permanent Magnet Motors: Modeling and Experimental Validation

Yves Perriard, Guillaume Paul-André Burnand

The purpose of this paper is to present an experimental method to separate losses components due to the rotation of the rotor in very-high-speed permanent magnet machines with ball bearings. In addition, it presents and validates an analytical model for th ...

2019

Silicon photonic MEMS variable optical attenuator

Niels Quack, Hamed Sattari, Teodoro Graziosi

We present a design for an on-chip MEMS-actuated Variable Optical Attenuator (VOA) based on Silicon Photonic MEMS technology. The VOA consists of 30 individual mechanically movable MEMS cantilevers, suspended over an integrated, 1 mu m wide bus waveguide, ...

SPIE-INT SOC OPTICAL ENGINEERING2018

Dynamic Modeling of Magnetic Components for Circuit Simulation of Power Electronic Systems

Min Luo

Magnetic components play an important role in a power electronic converter system. They provide energy buffering, galvanic isolation and voltage ratio conversion and have significant impact on the overall performance of the system regarding power efficienc ...

EPFL2018

Permeance Based Modeling of Magnetic Hysteresis with Inclusion of Eddy Current Effect

Drazen Dujic, Min Luo, Jost Allmeling

Magnetic hysteresis together with eddy current effects are typically present in metal based core materials and contribute significantly to the nonlinearity and power loss of the magnetic components operating in power electronic converters. In order to inve ...

IEEE2018

Mechanical Model for Drift-Induced Punching of Slab-Column Connections without Transverse Reinforcement

Aurelio Muttoni, Katrin Beyer, Ioannis Sokratis Drakatos

A mechanical model is presented for predicting the momentrotation relationship of interior slab-column connections without transverse reinforcement when subjected to seismically induced drifts. The model accounts explicitly for the three load-transfer acti ...

2018

Transient Impedance of Interconnected Wind Turbine Grounding Systems

Marcos Rubinstein, Antonio Sunjerga, Farhad Rachidi-Haeri, 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

Dispatching Stochastic Heterogeneous Resources Accounting for Grid and Battery Losses

Jean-Yves Le Boudec, Mario Paolone, Fabrizio Sossan, Lorenzo Enrique Reyes Chamorro, Eleni Stai

We compute an optimal day-ahead dispatch plan for distribution networks with stochastic resources and batteries, while accounting for grid and battery losses. We formulate and solve a scenario-based AC Optimal Power Flow (OPF), which is by construction non ...

2018

A wire shaped coaxial photovoltaic solar cell

Michael Graetzel, Mohammad Khaja Nazeeruddin, Carlos Perez, Mohammad Ibrahim Dar

A wire shaped coaxial photovoltaic solar cell comprising: a conductive core wire shaped support (401), a nanostructured semiconductor scaffold layer (402), one or more successive perovskite layers (403), an optionally provided hole transporting material la ...

2017

Central solenoid winding pack design for DEMO

Rainer Wesche, Pierluigi Bruzzone, Kamil Sedlák, Davide Uglietti, Boris Stepanov

The present study aims to reduce the outer radius of the central solenoid (CS) with respect to its nominal size specified by EUROfusion for a maintained CS magnetic flux. A reduced outer CS radius would allow the reduction of the overall size and cost of t ...

ELSEVIER2017

Modeling, Design, and Manufacturing of Microfabricated Coils With High Inductance Density

Yves Perriard, Yoan René Cyrille Civet, Douglas Martins Araujo, Florian Louis Copt, Jasha Poliakine

This paper addresses the design and manufacturing of small scale square planar coils with inductance densities ranging from 2 to 19 miH.mm-2. The design strategy is based on both analytic formulas and finite element method (FEM). Two different manufacturin ...

Institute of Electrical and Electronics Engineers2017