Publications associées à Automated hill chart modeling procedure to estimate the performance of double regulated units

On the prediction of the induced damage by the start-up sequence of Francis turbines: On operational resilience framework

Christophe Nicolet, Mario Paolone, Martin Seydoux, Elena Vagnoni

The number of transient operations in hydraulic machinery connected to power grid, notably start-ups and shut-downs, has observed a substantial increase in recent decades, primarily driven by the global shift toward intermittent renewable energy sources. S ...

Pergamon-Elsevier Science Ltd2024

Structural impact of the start-up sequence on Pelton turbines lifetime: Analytical prediction and polynomial optimization

Mario Paolone, Elena Vagnoni, Aldo Leonardo Alerci

Hydropower plants play a crucial role in the power system facing ambitious renewable energy targets. Due to their inherent controllability, they are well suited to provide flexibility to the grid. However, an increased flexibility provision leads to a prol ...

Pergamon-Elsevier Science Ltd2023

Aging investigation of the latest standard dual power modules using improved interconnect technologies by power cycling test

Yi Zhang, Rui Wu

The latest standard "New Dual" power module has been developed for both silicon and silicon-carbide devices to meet the increasing demands in high reliability and high temperature power electronic applications. Due to the new package is just starting to re ...

PERGAMON-ELSEVIER SCIENCE LTD2022

The COUGHVID crowdsourcing dataset: A corpus for the study of large-scale cough analysis algorithms

David Atienza Alonso, Lara Orlandic, Tomas Teijeiro Campo

Overview Cough audio signal classification has been successfully used to diagnose a variety of respiratory conditions, and there has been significant interest in leveraging Machine Learning (ML) to provide widespread COVID-19 screening. Th ...

Zenodo2021

A non-twisting flux tube for local gyrokinetic simulations

Stephan Brunner, Justin Richard Ball

Local gyrokinetic simulations use a field-aligned domain that twists due to the magnetic shear of the background magnetic equilibrium. However, if the magnetic shear is strong and/or the domain is long, the twist can become so extreme that it fails to prop ...

2021

Application of particle-based numerical analysis to the practical design of Pelton turbine

François Avellan, Siamak Alimirzazadeh, Takashi Kumashiro

For the design optimization of the Pelton turbine, it is highly demanded to investigate the flow inside the turbine casing, which includes the water jet from the nozzles, the interaction between the jet and rotating runner, and the flow ejected from the bu ...

IOP PUBLISHING LTD2021

Orchestration of oscillatory activity to improve visual motion discrimination

Roberto Felipe Salamanca Giron

This thesis describes advances in the use of novel configurations of non-invasive brain stimulation over the visual system allowing to modulate of modifying electro-physiological activity, interregional interactions and by it, visual behavior such as motio ...

EPFL2021

Transposition of the mechanical behavior from model to prototype of Francis turbines

François Avellan, Eduard Egusquiza, Joao Gomes Pereira Junior

Hydropower is nowadays essential for balancing the electrical grid providing flexibility and fast response. The role of hydraulic turbines has changed from working at their Best Efficiency Point (BEP) to work in the whole operating range when demanded. Fra ...

Pergamon-Elsevier Science Ltd2020

Wannier90 as a community code: new features and applications

Nicola Marzari, Giovanni Pizzi, Marco Gibertini, Lorenzo Paulatto, Hyungjun Lee, Daniel John Gilles Marchand, Antimo Marrazzo, Samuel Poncé, Junfeng Qiao

Wannier90 is an open-source computer program for calculating maximally-localised Wannier functions (MLWFs) from a set of Bloch states. It is interfaced to many widely used electronic-structure codes thanks to its independence from the basis sets representi ...

2020

Prediction of hydro-acoustic resonances in hydropower plants by a new approach based on the concept of swirl number

François Avellan, Christophe Nicolet, Christian Landry, Sébastien Alligné, Joao Gomes Pereira Junior, Arthur Tristan Favrel, Loïc Andolfatto

Hydropower plant units operating in off-design conditions are subject to cavitation flow instabilities, potentially inducing hydro-acoustic resonances under certain conditions. They can be predicted by using one-dimensional numerical models of hydropower p ...

Taylor & Francis Ltd2019

Predicting the dynamic behavior of Francis turbine generating units

Joao Gomes Pereira Junior

To reduce CO2 emissions and tackle global warming, an increasing amount of electrical power consumed around the world must be obtained from renewable sources. Among these sources, hydropower has not only the advantage of leaving a very small carbon footpri ...

EPFL2019

Physical Mechanism of Interblade Vortex Development at Deep Part Load Operation of a Francis Turbine

François Avellan, Arthur Tristan Favrel, Keita Yamamoto

For seamless integration of growing electricity production from intermittent renewable energy sources, Francis turbines are under increasing demand to extend their operating range. This requires Francis turbines to operate under off-design conditions, wher ...

ASME2019

Optimal Control of Part Load Vortex Rope in Francis Turbines

François Avellan, Simon Pasche, François Gallaire

The mitigation of the precessing vortex core developing in the draft tube of Francis turbines operating under part load conditions is crucial to increase the operation flexibility of these hydraulic machines to balance the massive power production of inter ...

ASME2019

Model testing beyond the scope of International Standards: an outlook

François Avellan, Loïc Andolfatto

The roles of hydropower plants within the energy system has been evolving during the last two decades. The potential to provide ancillary services to the grid is often harnessed, leading to a major change in hydropower plants operations. Ancillary services ...

2018

Monitoring a Francis Turbine Operating Conditions

François Avellan, Joao Gomes Pereira Junior, Loïc Andolfatto

Francis turbines are designed for a specific set of operating conditions that is particular to each hydropower plant site. It allows this type of turbine to extract as much hydraulic power as possible, as long as they are operating in the right conditions. ...

2018

Pumps running as turbines for energy recovery in water supply systems

João Nuno Gomes Borga Delgado

Pressurised water supply systems are infrastructures that offer a potential for energy recovery in locations where these systems operate with an excessive pressure. The integration of micro hydropower plants for energy recovery is a challenge, as these sys ...

EPFL2018

Biomimetic adaptive control of a deployable tensegrity structure

Ann Christine Sychterz

Biomimetic behavior includes aspects such as learning from previous experience, self-diagnosis, and adaptation. This thesis describes control methodologies that are essential to development towards biomimetic behavior of a complex deployable structure. Sim ...

EPFL2018

Fluid-structure interaction mechanisms leading to dangerous power swings in Francis turbines at full load

François Avellan, Christian Landry, Arthur Tristan Favrel

Hydropower plants play an important regulatory role in the large scale integration of volatile renewable energy sources into the existing power grid. This duty however requires a continuous extension of their operating range, provoking the emergence of com ...

Elsevier2017

RANS computations for identification of 1-D cavitation model parameters: application to full load cavitation vortex rope

François Avellan, Christophe Nicolet, Andres Müller, Sébastien Alligné

Due to the massive penetration of alternative renewable energies, hydropower is a key energy conversion technology for stabilizing the electrical power network by using hydraulic machines at off design operating conditions. At full load, the axisymmetric c ...

2017

Assessment of Power Swings in Hydropower Plants Through High-Order Modeling and Eigenanalysis

Basile Kawkabani, Christophe Nicolet, Pedro Camilo de Oliveira e Silva

POWER plants are subject to introduce disturbances in the power grid, resulting from interactions with the dynamical behavior of the energy source subsystem. In the case of hydropower plants when used to compensate for variations of power generation and co ...

2017