Publications de Nicolas Cherix

Control upgrade for the TCV coils power supplies

Damien Fasel, Ugo Siravo, Jérémie Dubray, Nicolas Cherix

The Tokamak a` Configuration Variable (TCV) coil converters are fed, during the plasma pulse, by a flywheel generator (FG) providing the AC voltages few seconds before the plasma pulse. The synchronization with the 120 Hz frequency delivered by the FG, var ...

ELSEVIER SCIENCE SA2023

Control of the Actively Balanced Capacitive Voltage Divider for a Five-Level NPC Inverter - Estimation of the Intermediary Levels Currents

Alfred Rufer, Nicolas Cherix, Nelson William Koch

This article addresses the control of a Multistage Stacked Boost Architecture (MSBA) feeding a five-level NPC inverter in a grid-tied application. A suitable control strategy was previously presented, in which estimated/reconstructed intermediary currents ...

2016

Functional Description and Control Design of Modular Multilevel Converters : Towards Energy Storage Applications for Traction Networks

Nicolas Cherix

The security of supply is becoming an important concern in the energy supply of the railway networks operated at 16.7â Hz. This situation calls for the improvement of the interconnection with the 50â Hz grid and creates a need for ancillary services, esp ...

EPFL2015

Operation and Control of Single-to-Three-Phase Direct AC/AC Modular Multilevel Converters under Asymmetric Grid Conditions

Alfred Rufer, Nicolas Cherix, Michail Vasiladiotis

Single-to-three-phase direct AC/AC Modular Multilevel Converters have gained a significant interest in the field of railway interties. The use of such an MMC-based structure implies more advanced control techniques as well as design requirements, especiall ...

2015

Single-to-Three-Phase Direct AC/AC Modular Multilevel Converters with Integrated Split Battery Energy Storage for Railway Interties

Alfred Rufer, Nicolas Cherix, Michail Vasiladiotis

This paper presents a global hierarchized control method for railway interties based on the direct singleto-three-phase AC/AC Modular Multilevel Converter with integrated split battery energy storage. The power and voltage decoupling between the converter ...

2015

Impact of Grid Asymmetries on the Operation and Capacitive Energy Storage Design of Modular Multilevel Converters

Alfred Rufer, Nicolas Cherix, Michail Vasiladiotis

The grid-connected modular multilevel converter (MMC) is very likely to operate under asymmetric grid conditions. Such a converter features several unique characteristics, whichmake its analysis different from other types of power converters in similar cas ...

Institute of Electrical and Electronics Engineers2015

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

Alfred Rufer, Nicolas Cherix, Michail Vasiladiotis

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

Operation of Modular Multilevel Converters Under Grid Asymmetries

Alfred Rufer, Daniel Siemaszko, Nicolas Cherix, Michail Vasiladiotis

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

Fail-safe Modular Control Platform for Power Electronic Applications in R&D Environments

Alfred Rufer, Philippe Barrade, Simon Delalay, Nicolas Cherix

This paper presents a modular control platform which is tailored for teaching and research applications. It aims at being entirely “student-proof” and features software-independent safety mechanisms, extensive signal conditioning and easy-to-use interfaces ...

2013

Sizing of branch inductors parameters in modular multilevel converters: An analytical approach

Alfred Rufer, Nicolas Cherix, Michail Vasiladiotis

One of the key features of Modular Multilevel Converters is the existence of inductors inside the branches that constitute each of their phases. These inductors, which may be coupled or non-coupled, authorize a certain independency in the control of the br ...

2013

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

Alfred Rufer, Nicolas Cherix, Michail Vasiladiotis

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

Dimensionnement formel des inductances de branches des Convertisseurs Modulaires Multiniveaux (MMC)

Alfred Rufer, Nicolas Cherix

Une des particularités essentielles des convertisseurs modulaires multiniveaux est la nature continue et sinusoïdale des courants qui les traversent. La présence d’inductances au centre de chacune de leurs phases autorise une certaine indépendance dans le ...

2012

Functional Modeling and Energetic Macroscopic Representation of Modular Multilevel Converters

Alfred Rufer, Nicolas Cherix, Michail Vasiladiotis

A key feature of Modular Multilevel Converters (MMC) is the continuous and independent nature of the branch currents. Therefore, a decoupled control of the line and partial bus currents is possible, unlike for classical topologies. To this end, several con ...

2012

Power and DC Link Voltage Control Considerations for Indirect AC/AC Modular Multilevel Converters

Alfred Rufer, Stephan Kenzelmann, Nicolas Cherix, Michail Vasiladiotis

A highly interesting application field of the Modular Multilevel Converter is the interconnection of the European three-phase 50 Hz industrial grid with the single-phase 16 2/3 Hz railway supply. Contrary to existing technologies, the utilization of a bulk ...

Ieee2011