Publications by Alfred Rufer | EPFL Graph Search

Related publications (215)

Design, modeling and experimental validation of a novel finned reciprocating compressor for Isothermal Compressed Air Energy Storage applications

Considering the need for a reliable and environmentally friendly energy storage solution for addressing renewable energy intermittency issue and following the developments on Isothermal Compressed Air Energy Storage (I-CAES) systems, a new finned piston co ...

Pergamon-Elsevier Science Ltd2017

Increasing the Energy Efficiency of Gas Boosters for Hydrogen Storage and for Refueling Stations

Alfred Rufer

A new electrically driven gas booster is described as an alternative to the classical air-driven gas boosters known for their poor energetic efficiency. These boosters are used in small scale Hydrogen storage facilities and in refueling stations for Hydrog ...

MDPI2023

Gas Turbine: Optimization of Energy Production and High Efficiency by Using Power Electronics

Alfred Rufer, Aziza Benaboud

The use of gas turbines in the power generation industry has been increasing. Their demand represents more than 50% of the world market of thermal power plants. Electric power generators using gas turbines as power sources are connected to the turbines thr ...

Elsevier Science Bv2016

Thermo-Electric Analogy Method for Computing Transient Heat Transfer in a New Reciprocating Finned Piston Compressor

John Richard Thome, Alfred Rufer, Mahbod Heidari

In the framework of Isothermal Compressed Air Energy Storage (CAES), a new finned piston compressor has been designed and realized at LEI laboratory in EPFL. This system comprises a series of concentric annuli’s fitting into each other compressing the air ...

2014

A Hybrid Energy Storage System Based on Compressed Air and Super Capacitors With Maximum Efficiency Point Tracking (MEPT)

Alfred Rufer, Sylvain Lemofouet-Gatsi

In addition to the high-capacity storage facilities based on hydropower technologies, electrochemical solutions are today’s candidate for storage for renewable energy sources support. However, sustainability and limited life cycles of batteries are often i ...

2006

Hybrid Energy Storage Systems based on Compressed Air and Supercapacitors with Maximum Efficiency Point Tracking

Alfred Rufer, Sylvain Lemofouet-Gatsi

Beside the high-capacity storage facilities based on hydro-power technologies, electrochemical solutions are the today's candidate for storage for renewable energy sources. However, limited life-cycles and sustainability of batteries are often inhibiting f ...

2005

Multistage hydraulic gas compression/expansion systems and methods

Alfred Rufer

Multistage hydraulic systems and methods for converting the potential energy of a pressurized gas, particularly air, into mechanical work operating in motor, and for producing compressed gas from the mechanical work of the rotating shaft (A1.1 ) when rotat ...

2009

Vector Control of Single-Phase Voltage-Source Converters Based on Fictive-Axis Emulation

Alfred Rufer, Stephan Kenzelmann, Behrooz Bahrani

This paper presents an alternative way for the current regulation of single-phase voltage-source dc-ac converters in direct-quadrature (dq) synchronous reference frames. In a dq reference frame, ac (time varying) quantities appear as dc (time invariant) on ...

Institute of Electrical and Electronics Engineers2011

Direct Connection of Supercapacitors to Photovoltaic Panels With On–Off Maximum Power Point Tracking

Alfred Rufer, Philippe Barrade, Simon Delalay

A system dedicated to energy storage is presented. It allows energy storage from photovoltaic panels to a compressed air accumulator. This accumulator is controlled to enable compression and expansion modes under Maximum Efficiency Point Tracking (MEPT). A ...

2012

A Multivariable Design Methodology for Voltage Control of a Single-DG-Unit Microgrid

Alfred Rufer, Alireza Karimi, Behrooz Bahrani

This paper proposes a multivariable digital control design methodology for the voltage regulation of an islanded single distributed generation (DG) unit microgrid and its dedicated load. The controller design methodology is based on a family of spectral Mu ...

2013

Vector Control of Single-Phase Voltage Source Converters based on Fictive Axis Emulation

Alfred Rufer, Stephan Kenzelmann, Behrooz Bahrani

This paper presents an alternative way for controlling the current of single-phase voltage source dc-ac inverters in a dq synchronous reference frame. In a dq reference frame, ac (time varying) quantities appear as dc (time invariant) quantities allowing t ...

Ieee Service Center, 445 Hoes Lane, Po Box 1331, Piscataway, Nj 08855-1331 Usa2009

Toward Ultrafast Charging of Electric Vehicles

Alfred Rufer, Hans Björn Püttgen, Massimiliano Capezzali, Michail Vasiladiotis, Hardi Hõimoja, Stefano Grioni

The paper is devoted to the problems arising from the ultrafast (≤ 10 min) charging of an electric vehicle (EV). An ultrafast charging station (UFCS) must provide high power output with minimal influence on the electricity transmission system, which can on ...

2012

Modeling of a Reciprocating Air Compressor using Energetic Macroscopic Representation

Alfred Rufer, Mahbod Heidari

This article introduces the energetic macroscopic representation (EMR) as approach for the dynamic nonlinear modeling of a reciprocating air compressor. EMR has been introduced recently for research development in complex electromechanical systems. It is b ...

2012

Operation of Modular Multilevel Converters Under Grid Asymmetries

Daniel Siemaszko, Alfred Rufer, Michail Vasiladiotis, Nicolas Cherix

The Modular Multilevel Converter is very likely to operate in a grid-connected mode under asymmetric conditions. Such a converter features several unique characteristics, which make its analysis different from other types of power converters in similar cas ...

2013

A novel 60 MW Pulsed Power System based on Capacitive Energy Storage for Particle Accelerators

Alfred Rufer

Large Physics experimentation as in particle accelerators or in nuclear fusion is often characterised by a strong and modulated power demand, incompatible with the power availability of the grid. Therefore, large facilities for short-term energy storage ha ...

2007

Principle of Hybrid Energy Storage Systems based on Hydro-pneumatics and Supercapacitors for Distributed Generation and Renewable Energy Sources Support

Alfred Rufer, Sylvain Lemofouet-Gatsi

This paper presents hybrid energy storage systems based on hydro-pneumatics and Supercapacitors with high potentials regarding life cycle and impacts on environment. These so called “Batteries with Oil-hydraulics and Pneumatics (BOP)” systems exploit the h ...

2005

Dynamic Analysis and State Feedback Voltage Control of Single-Phase Active Rectifiers with DC-Link Resonant Filters

Alfred Rufer, Michail Vasiladiotis

Single-phase active rectifiers exhibit an inherent strong second-order current harmonic on their DC-link. The latter is often undesirable from a load point of view and is therefore chosen to be eliminated. A common method is the use of a resonant passive L ...

Ieee-Inst Electrical Electronics Engineers Inc2014

Accurate Voltage Ripple Estimation and Decoupled Current Control for Modular Multilevel Converters

Alfred Rufer, Michail Vasiladiotis, Nicolas Cherix

The analytical solution for the sub-module voltage ripple equations of a Modular Multilevel Converter (MMC) is derived, based on the knowledge of the external voltage/current magnitudes and enhancing a concept previously presented in literature. In order t ...

2012

Accurate Capacitor Voltage Ripple Estimation and Current Control Considerations for Grid-Connected Modular Multilevel Converters

Alfred Rufer, Michail Vasiladiotis, Nicolas Cherix

In this paper the analytical solution for the submodule voltage ripple equations of a Modular Multilevel Converter (MMC) is derived, based on the knowledge of the external voltage/current magnitudes, and enhancing a concept previously presented in literatu ...

Ieee-Inst Electrical Electronics Engineers Inc2014

Stockage d'énergie par air comprimé. Un défi pour les circuits d'électronique de puissance

Alfred Rufer, Sylvain Lemofouet-Gatsi

The principle of air compression can be utilized for the storage of electrical energy, with variable properties from the point of view of the energy efficiency. For the involved thermodynamic phenomena different approaches and realized systems lead to more ...

2007