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See detailPOWER PROCESSING UNIT ACTIVITIES AT THALES ALENIA SPACE BELGIUM
Bourguignon, Eric; Fraselle, Stéphane; Scalais, Thierry et al

in Proceedings of Space propulsion Conference 2014 (2014)

Since 1996, Thales Alenia Space Belgium (ETCA) designs, develops and produces Power Processing Unit (PPU) to supply Hall Effect Thrusters: SPT-100 from Fakel and PPS1350-G from Snecma. The first ... [more ▼]

Since 1996, Thales Alenia Space Belgium (ETCA) designs, develops and produces Power Processing Unit (PPU) to supply Hall Effect Thrusters: SPT-100 from Fakel and PPS1350-G from Snecma. The first qualification model, developed for the 50V bus Stentor program, has supplied during 8900 hours an SPT-100 thruster in a vacuum chamber simulating space environment. Qualified for the Spacebus 4000 platform, with a 100V regulated bus, the SB4000 PPU and Filter Unit EQM have cumulated 6300 hours ground operation with a PPS1350-G thruster. Twenty three PPU flight models were delivered for the Stentor, Astra-1K, Smart-1, Intelsat, Inmarsat, Eutelsat, Yahsat and DirecTV satellites. In October 2005, the Smart-1 spacecraft reached the Moon after 4958 hours of cumulated operation of the PPU with PPS1350-G thruster. Fourteen PPU’s currently in flight for North South Station Keeping on seven telecom satellites have cumulated more than 24100 hours flight operation. Following the selection of the PPS1350-G as baseline thruster for the AlphaBus platform, the Alphabus PPU was developed and two flight models were delivered for AlphaSat. Launched in July 2013, they have cumulated 350 hours operation. On the SmallGEO platform, one EPTA (Electric Propulsion Thruster Assembly) branch has to drive one out of four SPT-100 thrusters. As the PPU drives one out of two thrusters, TAS-B (ETCA) has developed and qualified an External Thruster Selection Unit (ETSU) to be associated to a PPU. Two flight sets (PPU+ETSU) were delivered for SmallGEO. In order to propose a more competitive product TAS-B (ETCA) has developed the new generation of PPU, called PPU Mk2, dedicated to Hall Effect Thrusters up to 2.5kW. The qualification phase is ending with the Qualification Test Review Board successfully hold in April 2014 and the final Qualification Review planned in June 2014. Twelve PPU Mk2 flight models are already ordered by two customers. In response to the market demand to use Electrical Propulsion for Orbit Raising, TAS-B (ETCA) has started the development of the PPU Mk3 dedicated to 5kW Hall Effect Thrusters. This paper presents an overview of the Power Processing Unit activities at TAS-B (ETCA), including flight heritage, PPU Mk2 qualification and the development of PPU Mk3. [less ▲]

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See detailPower system observability and related functions : derivation of appropriate strategies and algorithms
Van Cutsem, Thierry ULg

in International Journal of Electrical Power & Energy Systems (1985), 7

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See detailPower system security assessment: a position paper
Marceau, R.J.; Endrenyi, J.; Allan, R. et al

in Electra (1997), 175

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See detailPower System Simulation Challenges
Aristidou, Petros ULg; Plumier, Frédéric ULg; Van Cutsem, Thierry ULg et al

Scientific conference (2013, March 05)

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See detailPower system transient stability preventive and emergency control
Ruiz-Vega, Daniel; Wehenkel, Louis ULg; Ernst, Damien ULg et al

in Savulescu, Savu (Ed.) Real-Time Stability in Power Systems 2nd Edition (2014)

A general approach to real-time transient stability control is described, yielding various complementary techniques: pure preventive, open loop emergency, and closed loop emergency controls. Recent ... [more ▼]

A general approach to real-time transient stability control is described, yielding various complementary techniques: pure preventive, open loop emergency, and closed loop emergency controls. Recent progress in terms of a global transient stability constrained optimal power flow are presented, yielding in a scalable nonlinear programming formulation which allows to take near-optimal decisions for preventive control with a computing budget corresponding only to a few runs of standard optimal power flow and time domain simulations. These complementary techniques meet the stringent conditions imposed by the real-life applications. [less ▲]

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See detailPower systems stability control: Reinforcement learning framework
Ernst, Damien ULg; Glavic, Mevludin; Wehenkel, Louis ULg

in IEEE Transactions on Power Systems (2004), 19(1), 427-435

In this paper, we explore how a computational approach to learning from interactions, called reinforcement learning (RL), can be applied to control power systems. We describe some challenges in power ... [more ▼]

In this paper, we explore how a computational approach to learning from interactions, called reinforcement learning (RL), can be applied to control power systems. We describe some challenges in power system control and discuss how some of those challenges could be met by using these RL methods. The difficulties associated with their application to control power systems are described and discussed as well as strategies that can be adopted to overcome them. Two reinforcement learning modes are considered: the online mode in which the interaction occurs with the real power system and the offline mode in which the interaction occurs with a simulation model of the real power system. We present two case studies made on a four-machine power system model. The first one concerns the design by means of RL algorithms used in offline mode of a dynamic brake controller. The second concerns RL methods used in online mode when applied to control a thyristor controlled series capacitor (TCSC) aimed to damp power system oscillations. [less ▲]

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See detailPower transmission and particle acceleration along the Io flux tube
Hess, Sebastien L G; Delamere, Peter; Dols, Vincent et al

in Journal of Geophysical Research. Space Physics (2010), 115

Io's motion relative to the Jovian magnetic field generates a power of about 10^12 W, which is thought to propagate as an Alfven wave along the magnetic field line. This power is transmitted to the ... [more ▼]

Io's motion relative to the Jovian magnetic field generates a power of about 10^12 W, which is thought to propagate as an Alfven wave along the magnetic field line. This power is transmitted to the electrons, which will then precipitate and generate the observed auroral phenomena from UV to radio wavelengths. A more detailed look at this hypothesis shows some difficulties: Can the Alfven waves escape the torus or are they trapped inside? Where and how are the particles accelerated? In which direction? Is there enough power transmitted to the particles to explain the strong brightness of the auroral emissions in UV, IR, visible, and radio? In other words, can we make a global, consistent model of the Io-Jupiter interaction that matches all the observations? To answer these questions, we review the models and studies that have been proposed so far. We show that the Alfven waves need to be filamented by a turbulent cascade process and accelerate the electrons at high latitude in order to explain the observations and to form a consistent scheme of the Io-Jupiter interaction. [less ▲]

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See detailPowerful Alternative Asymmetric Catalytic Dihydroxylation of Olefins
Colaux, Catherine ULg; Krief, Alain

Poster (2000, November)

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See detailPowerful alternative asymmetric Catalytic dihydroxylation of olefins
Colaux, Catherine ULg; Krief, Alain; Dumont, Willy

Poster (1998, November)

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See detailPowerful alternative asymmetric catalytic dihydroxylation of olefins
Colaux, Catherine ULg; Krief, Alain

Poster (1998, December)

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See detailPowerful Alternative Asymmetric Catalytic Dihydroxylation of Olefins
Colaux, Catherine ULg; Krief, Alain

Poster (2000, July)

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See detailPowerpoint "Les conditions de production de la communication" (33 p)
Geuens, Geoffrey ULg

Learning material (2010)

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See detailPowerpoint "Les principaux groupes médiatiques belges privés" (9 pages)
Geuens, Geoffrey ULg

Learning material (2014)

Detailed reference viewed: 29 (3 ULg)
See detailPowerPoint : Histoire de l'art de l'époque Contemporaine I et II
Bawin, Julie ULg

Learning material (2005)

Le cours d’Histoire de l’art de l’époque contemporaine (I et II) s’adresse à des étudiants ayant une connaissance préalable des mouvements artistiques qui jalonnent les XIXe et XXe siècles (cf. cours de ... [more ▼]

Le cours d’Histoire de l’art de l’époque contemporaine (I et II) s’adresse à des étudiants ayant une connaissance préalable des mouvements artistiques qui jalonnent les XIXe et XXe siècles (cf. cours de 1er bac). Donné de manière « cyclique », le cours se divise en deux grandes parties : une première est consacrée au mouvement d’intérêt suscité par l’art japonais dans la seconde moitié du XIXe siècle et à ses prolongements après 1945 ; une seconde partie traite de problématiques variées liées à la création artistique depuis 1960 jusqu’à nos jours et consacre également une partie du cours à l’histoire de la photographie. De manière générale, ce cours a pour objectif de fournir à la fois les données historiques, stylistiques et tout éclairage (d'ordre philosophique, sociologique, politique, économique, scientifique, littéraire...) utiles à une compréhension plus approfondie des formes d'expressions plastiques de l’art moderne et contemporain. [less ▲]

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See detailPowerPoint : Histoire de l'art et archéologie : l'Époque contemporaine : le XXe siècle
Bawin, Julie ULg

Learning material (2009)

Le cours a pour objet de fournir à la fois les données historiques, stylistiques et tout éclairage (d'ordre philosophique, sociologique, politique, économique, scientifique, littéraire...) utiles à la ... [more ▼]

Le cours a pour objet de fournir à la fois les données historiques, stylistiques et tout éclairage (d'ordre philosophique, sociologique, politique, économique, scientifique, littéraire...) utiles à la compréhension des formes d'expressions plastiques (architecture, peinture, sculpture, ainsi que, dans la mesure du possible, arts graphiques et arts dits "appliqués") qui se sont succédé et/ou opposé de 1900 à nos jours. [less ▲]

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See detailPowerPoint : Histoire de l’art et archéologie de l’époque contemporaine (Université de Namur)
Bawin, Julie ULg

Learning material (2012)

Le cours a pour objectif de livrer les connaissances de base en histoire de l’art et archéologie des XIXe et XXe siècles. Y sont abordées les formes d'expressions plastiques (architecture, peinture ... [more ▼]

Le cours a pour objectif de livrer les connaissances de base en histoire de l’art et archéologie des XIXe et XXe siècles. Y sont abordées les formes d'expressions plastiques (architecture, peinture, sculpture, arts graphiques, arts appliqués) qui se sont succédées et/ou opposées dans le monde occidental depuis la fin du XVIIIe siècle jusqu’à nos jours. Outre l’initiation à l’analyse des monuments et des œuvres, et à leur interprétation dans une perspective historique, le cours se veut le cadre de réflexions (philosophique, sociologique, littéraire, politique et économique, etc.) utiles à a compréhension des différentes ruptures qui se sont opérées pendant plus de deux siècles. Pour davantage de clarté, la matière est divisée en quatre grandes parties correspondant à quatre grandes périodes : 1789-1848 / 1848-1900 / 1900-1960/ 1960 à nos jours. [less ▲]

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