Publications related to Electric machine

Alignment of ND3 molecules in dc-electric fields

Andreas Osterwalder, Viet Le Duc, Junwen Zou

The control of movement and orientation of gas-phase molecules has become the focus of many research areas in molecular physics. Here, ND3 molecules are polarized in a segmented, curved electrostatic guide and adiabatically aligned inside a rotatable mass ...

Aip Publishing2024

Analytical Computation of the Sensitivity Coefficients in Hybrid AC/DC Networks

Mario Paolone, Willem Lambrichts

In this paper, we present a model for the analytical computation of the power flow sensitivity coefficients (SCs) for hybrid AC/DC networks. The SCs are defined as the partial derivates of the nodal voltages with respect to the active and reactive power in ...

2024

Torque Computation With the Isogeometric Mortar Method for the Simulation of Electric Machines

Rafael Vazquez Hernandez, Bernard Kapidani

In this work, isogeometric mortaring is used for the simulation of a six-pole permanent magnet synchronous machine. Isogeometric mortaring is especially well suited for the efficient computation of rotating electric machines, as it allows for an exact geom ...

Institute of Electrical and Electronics Engineers2022

Modelling and Sensors for Magnetically-Levitated Disc Drives

Juan Patricio Tomás Peralta Fierro

The development of new industrial applications has diverted the focus of research towards compacter and faster rotatory drives. These requirements push the classical ball-bearings of electric motors to the limits in terms of operational lifetime and fricti ...

EPFL2022

Long Spin Lifetime in Rare-Earth Single-Atom Magnets at Surfaces

Boris Sorokin

Further miniaturisation of magnetic storage devices requires an advent of new types of magnets, since classical ferromagnetic materials show lack of remanence at nano- and subnanoscale. A single atom can represent the smallest possible bit of information. ...

EPFL2022

Ferroelectric Effects Probed by in situ Transmission Electron Microscopy

Reinis Ignatans

Ferroelectric perovskite oxides are widely used in sensors, actuators and optical modulators and, at the same time, they show promise for implementation in future applications such as energy storage, memory and cooling devices. At the infancy of the discov ...

EPFL2022

Hybrid Modular Multilevel Converter for Pumped Hydro Storage Applications

Miodrag Basic

Energy balance in a power system must be maintained at all times, regardless of the variations in generation and consumption. Large Pumped Hydro Storage Plants (PHSPs) are introduced to the power system to accumulate the excess of energy during the low dem ...

EPFL2022

Lifetime of dielectric elastomer actuators under DC electric fields

Fabio Beco Albuquerque

Dielectric elastomer actuators (DEAs) are interesting soft actuators compared to other actuation technologies owing to large achievable actuation strains, high energy density and fast actuation. However, because DEAs need to be operated under high electric ...

EPFL2022

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

Efficiency Optimisation of Slotless Magnetic Bearing Machines

Yves Perriard, Douglas Martins Araujo, Leopoldo Rossini, Guzmán Borque Gallego

Efficiency is one of the key performance indexes in the design of electric motors. When considering fully active magnetic bearing machines, this aspect gain further relevance due to the necessity of actively controlling all the remaining degrees of freedom ...

2021

Experimental Investigation of a Small-Scale Organic Rankine Cycle Turbo-Generator Supported on Gas-Lubricated Bearings

Jürg Alexander Schiffmann, Kévin Rosset

Waste heat recovery (WHR) is expected to contribute to reducing CO2 emissions from trucks. Organic Rankine cycle (ORC) systems show the highest potential for this application, but still lack efficient small-scale expansion devices, in practice. A novel tur ...

2021

High-Performance Enhancement-Mode AlGaN/GaN Multi-Channel Power Transistors

Elison de Nazareth Matioli, Remco Franciscus Peter van Erp, Halil Kerim Yildirim, Jun Ma, Luca Nela, Catherine Erine

AlGaN/GaN devices have shown outstanding potential for power conversion applications. However, despite the recent progress, their performance is still far from what the material can offer in terms of on-resistance and breakdown voltage. To address this cha ...

IEEE2021

Characterization and Verification of Eddy-Current Position Sensing for Magnetic Levitation

Yves Perriard, Sean Thomas, Juan Patricio Tomás Peralta Fierro

Magnetically-levitated drives are compelling in applications where the long-lifetime operation or process chamber encapsulation is a requirement. To exploit these advantages, contactless position sensors are needed to estimate the position of the rotor. Of ...

2021

Effect of electrode composition and patterning method on the lifetime of silicone-based dielectric elastomer actuators (DEA) under different environmental conditions

Herbert Shea, Fabio Beco Albuquerque

We report an experimental investigation of the lifetime of dielectric elastomer actuators (DEAs) under constant DC actuation, with a characterization setup which allows the monitoring of strain and resistance over time for 6 DEAs in parallel. We show how t ...

SPIE-INT SOC OPTICAL ENGINEERING2021

Progress on the Design of the 15 T Magnet of the EDIPO Test Facility

Pierluigi Bruzzone, Kamil Sedlák, Roberto Guarino, Evgeny Solodko

EDIPO 2 (the upgraded EDIPO test facility) will provide a unique testbed for superconducting cables for fusion magnets,accelerators, and other applications. Compared to the previous magnet assembly, the magnetic field is enhanced from 12.35 T to 15 T, the ...

IEEE Institute of Electrical and Electronics Engineers2021

Influence of electric field, temperature, humidity, elastomer material, and encapsulation on the lifetime of dielectric elastomer actuators (DEAs) under DC actuation

Herbert Shea, Fabio Beco Albuquerque

We present the effect of electric field, temperature, humidity, type of elastomer material, and encapsulation on the lifetime of silicone-based dielectric elastomer actuators (DEAs) under DC electric fields. DEAs are promising soft actuators, but little ha ...

IOP Publishing Ltd2021

Performance and Micro-Vibrations in Magnetic Bearings for Space Actuators

Guzmán Borque Gallego

The development of new space missions with novel high-performance and very sensitive payloads for Earth observation or scientific missions has imposed considerably tougher requirements in terms of the satellite's pointing accuracy and stability, and thus o ...

EPFL2021

The Influence of O-2 on Positive Streamer Initiation in Supercritical CO2 With Field Ionization Using a 3-D Particle Model

Guang-Yu Sun

In this work, the influence of varying mixing ratios of O-2 on positive streamer initiation in supercritical (SC) CO2 at different applied voltages was investigated using a 3-D particle model. Zener's model was included in the 3-D particle model to calcula ...

2021

Nonlinear study on a rigid rotor supported by herringbone grooved gas bearings: Theory and validation

Jürg Alexander Schiffmann, Patrick Hubert Wagner, Philipp Kaspar Bättig, Wanhui Liu

The nonlinear behavior of a rigid rotor supported by herringbone grooved journal gas bearings (HGJBs) was investigated in this study. The two-dimensional narrow groove theory (2D-NGT) was adopted to model the HGJBs. A set of integrated rotor-bearing state ...

2021

A cryogenic electro-optic interconnect for superconducting devices

Tobias Kippenberg, Amir Youssefi, Anton Lukashchuk, Nathan Rafaël Bernier, Liu Qiu, Itay Shomroni

A major challenge to the scalability of cryogenic computing platforms is the heat load associated with the growing number of electrical cable connections between the superconducting circuitry and the room-temperature environment. Compared with electrical c ...

2021