Publications associées à Transposition of the mechanical behavior from model to prototype of Francis turbines

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

Study of flexible operating conditions in variable-speed hydraulic turbines : advanced models and experimental validation

Martin Seydoux

The global imperative to transition from fossil fuel-based energy sources to renewable alternatives has become increasingly urgent in the pursuit of sustainable and renewable power generation. This paradigm shift necessitates innovative approaches to manag ...

EPFL2024

Enhancing Wind Farm Performance through Axial Induction and Tilt Control: Insights from Wind Tunnel Experiments

Fernando Porté Agel, Guillem Armengol Barcos

Static axial induction control and tilt control are two strategies that have the potential to increase power production in wind farms, mitigating wake effects and increasing the available power for downstream turbines. In this study, wind tunnel experiment ...

MDPI2024

Power performance of a model floating wind turbine subjected to cyclic pitch motion: A wind tunnel study

Fernando Porté Agel, Guiyue Duan, Daniele Gattari

Wind tunnel experiments were performed with a miniature floating wind turbine model to study the effects of cyclic pitch motion on its power performance. The cyclic pitch motion was prescribed by two key parameters: pitch frequency and amplitude. The power ...

IOPscience2024

Advanced control strategies to exploit the hydropower potential enhancing ancillary services provision to the power system

Francesco Gerini

The European Union's Green Deal aims for a 55% reduction in greenhouse gas emissions by 2030. To reach this goal, a massive integration of Renewable Energy Sources (RES) into the power grid is necessary. As RES become a large part of the electricity genera ...

EPFL2024

Wind turbine wake superposition under pressure gradient

Fernando Porté Agel, Arslan Salim Dar

We investigate the effect of pressure gradient on the cumulative wake of multiple turbines in wind tunnel experiments spanning across a range of adverse pressure gradient (APG), zero pressure gradient (ZPG), and favorable pressure gradient (FPG). Compared ...

2024

Towards an improved understanding of wind turbine wakes in complex terrain

Arslan Salim Dar

In this thesis, we explored the effect of certain terrain-induced flow phenomena on the development of wind turbines sited in complex terrain. A combined experimental and analytical approach is used to study wind turbine wakes in different types of complex ...

EPFL2024

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

Dynamic stall characterisation and control for vertical-axis wind turbines

Sébastien Le Fouest

According to the International Energy Agency, the global net-zero emissions objective requires the installed wind power capacity to increase 11-fold between 2020 and 2050. The scientific community has recently voiced concerns about the logistic feasibility ...

EPFL2023

Cross-code verification of non-neutral ABL and single wind turbine wake modelling in LES

Fernando Porté Agel, Marwa Souaiby

Large Eddy Simulations (LES) of atmospheric boundary layer (ABL) flow with the actuator disc (AD) for turbine modelling is a widely used method of simulating wind farm flows. Hence, it is important to understand the requirements for achieving a good compar ...

IOP PUBLISHING LTD2023

CFD simulations of hydraulic short-circuits in junctions, application to the Grand’Maison power plant

François Avellan, Cécile Münch-Alligné

In the framework of the XFLEX HYDRO H2020 European Project, the pumped-storage power plant of Grand'Maison (France), owned by Electricité De France, focuses on the implementation of the hydraulic short-circuit (HSC) operating mode. This mode increases the ...

2022

Discretization Uncertainties of Flow and Fatigue Damage Simulations of a Reversible Francis Pump-Turbine at Off-Design Operation in Turbine Mode

Philippe Alexandre Bontemps, Drazen Dujic, Daniel Biner

In the framework of the XFLEX HYDRO H2020 European Project, a 5 MW reversible Francis pump-turbine prototype, equipped with an industrial full size frequency converter, is investigated to demonstrate enhanced grid regulation capacities of variable speed hy ...

SPRINGER INTERNATIONAL PUBLISHING AG2022

Wind farm layout and unconstrained hub height optimization using genetic algorithms applied to different power densities

Fernando Porté Agel, Nicolas Otto Kirchner Bossi

LES and wind tunnel studies have shown significant benefit when allowing turbines (T) in a wind farm to adopt different heights. This work presents two new genetic algorithms (GA) that perform wind farm layout optimization (WFLO) involving continuous and t ...

2022

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

Numerical simulations of Pelton turbine flow to predict large head variation influence

François Avellan, Steve Crettenand, Cécile Münch-Alligné, Siamak Alimirzazadeh

In the framework of the new feed-in-tariff system in Switzerland for Small Hydropower Plants (SHP), the aim of the SmallFLEX project, led by HES-SO Valais and performed in collaboration with EPFL, WSL, EAWAG, PVE, and FMV, is to show how SHP can provide wi ...

IOP PUBLISHING LTD2021

Optimal CAM Computation of Kaplan Turbines Accounting for Wear and Tear Originated by Frequency Control

Sidi-Rachid Cherkaoui, Mario Paolone, Elena Vagnoni, Francesco Gerini

Nowadays, the importance of providing frequency stability to power systems with hydropower units is significantly increasing due to the growing proportion of volatile renewable energy sources. However, the provision of such services, as frequency containme ...

IEEE2021

Improving frequency containment reserve provision in run-of-river hydropower plants

Sidi-Rachid Cherkaoui, Mario Paolone, Elena Vagnoni, Francesco Gerini

The paper presents a model-based control strategy for optimal asset management of hydroelectric units in run-of-river hydropower plants. The proposed control strategy aims to operate the unit at the best efficiency while improving water flow management and ...

2021

Numerical investigation on the volute cutwater for pumps running in turbine mode

Elena Vagnoni, Alessandro Morabito

The hydropower sector has recently raised the interest in pump as turbine (PaT) that can be a valid trade-off between capital cost and performance in micro-scale installations. Nevertheless, the modest efficiency of PaTs often restricts their exploitation. ...

Pergamon-Elsevier Science Ltd2021

An experimental study on the upper part-load elliptical vortex instability in a Francis turbine

François Avellan, Andres Müller, Arthur Tristan Favrel, Elena Vagnoni, Ali Amini

This paper presents preliminary results of an experimental study on the occurrence and development of the upper part-load instability in a reduced-scale Francis turbine. The study includes draft tube pressure measurements, high-speed flow visualization, an ...

IOP PUBLISHING LTD2021

CFD simulations of a Y-junction for the implementation of hydraulic short-circuit operating mode

François Avellan, Cécile Münch-Alligné, Daniel Biner

In the framework of the XFLEX HYDRO H2020 European Project, one of the demonstrators focuses on the implementation of the hydraulic short-circuit on the pump storage power plant of Grand-Maison owned by Electricite De France (EDF). The Grand-Maison power p ...

IOP PUBLISHING LTD2021