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See detailDYNAMIC LINE RATING AND AMPACITY FORECASTING AS THE KEYS TO OPTIMISE POWER LINE ASSETS WITH THE INTEGRATION OF RES. THE EUROPEAN PROJECT TWENTIES DEMONSTRATION INSIDE CENTRAL WESTERN EUROPE
Nguyen, Huu-Minh ULg; Schell, Peter; Lilien, Jean-Louis ULg

in Proceedings of Congrès International des Réseaux Electriques de Distribution (2013, June 12)

The general increase of Distributed & intermittent renewable Generation is pushing TSOs and DSOs to find innovative solutions to increase the capacity of their networks. Dynamic Line Rating (DLR) has ... [more ▼]

The general increase of Distributed & intermittent renewable Generation is pushing TSOs and DSOs to find innovative solutions to increase the capacity of their networks. Dynamic Line Rating (DLR) has proven to be a very promising solution to cope with this issue. However, few experiments so far have addressed ampacity forecasting, which is critical to allow the integration of DLR in the electricity market processes. To tackle this gap, we developed an algorithm based on real-time DLR measurements and weather forecasts, which provides ampacity forecasts up to two days ahead. This paper describes the results of the EU-funded TWENTIES Demo led in Belgium on two 150kV lines. Currently, the DLR system used provides a two-day ahead ampacity forecast with more than 10% average gain over static rating (dynamic gain forecast varying roughly between 0% and 30%) with 98% confidence. Operational gains allowed by this increase of flexibility are still being assessed. [less ▲]

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See detailDynamic loads caused by lightning stroke in a conductor angle arrangement.
Lilien, Jean-Louis ULg; hansenne, eric; Kokkinos, D. et al

in Proceedings of teh 23rd ICLP (1996, September)

Lightning stroke going through condutor angle may cause dramatic failure of the conductors if mechanical loads are not taken into account in the design.The paper evaluate such effects by simulation and ... [more ▼]

Lightning stroke going through condutor angle may cause dramatic failure of the conductors if mechanical loads are not taken into account in the design.The paper evaluate such effects by simulation and make some proposal to reduce the maximum stress. [less ▲]

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See detailDynamic mechanical thermal and infrared analyses of polyacrylonitrile "electrografted" onto a metal
Calberg, Cédric ULg; Mertens, Marc; Baute, Noëlle et al

in Journal of Polymer Science. Part B, Polymer Physics (1998), 36(4), 543-553

Polyacrylonitrile (PAN) films have been grafted onto copper electrodes by cathodic polarization and analyzed by infrared spectroscopy and dynamic mechanical thermal analysis (DMTA). The dynamic mechanical ... [more ▼]

Polyacrylonitrile (PAN) films have been grafted onto copper electrodes by cathodic polarization and analyzed by infrared spectroscopy and dynamic mechanical thermal analysis (DMTA). The dynamic mechanical response shows two or three transitions depending on the film thickness and the potential deposition. The viscoelastic properties of ungrafted PAN films, e.g., solvent cast films of commercially available PAN, are deeply different from those of electrografted films. The experimental data support that ungrafted chains are paracrystalline in contrast to the grafted ones which are essentially amorphous. Moreover, the irreversible transformation of the grafted PAN chains observed beyond 225°C is confirmed by Fourier transform infrared (FTIR) analysis and ascribed to an intramolecular cyclization of PAN into polyimine. This reaction occurs rapidly and at a comparatively low temperature with respect to ungrafted PAN, which suggests that the grafted chain configuration might be predominantly isotactic. The isotacticity and the amorphous structure appear to decrease as the thickness of the PAN film is increased. Literature data and the herein reported observations would suggest a dependence of the amorphous structure of PAN on the chain isotacticity. [less ▲]

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See detailA dynamic model of an experimental bloom of coccolithophores Emiliania huxleyi
Joassin, Pascal ULg; Borges, Alberto ULg; Chou, Lei et al

Conference (2007, November 27)

A dynamic model has been developed to represent biogeochemical events observed during an experimentally induced bloom of coccolithophores Emiliania huxleyi. This bloom occurred in a mesocosm experiment ... [more ▼]

A dynamic model has been developed to represent biogeochemical events observed during an experimentally induced bloom of coccolithophores Emiliania huxleyi. This bloom occurred in a mesocosm experiment (Bergen 2001 experiment) during which ecosystem development was followed over a 23-days period through changes of the stocks of inorganic nutrients (nitrate, ammonium and phosphate), dissolved inorganic carbon and pCO2, O2 concentration, pigments, particulate organic carbon and nitrogen, dissolved organic carbon, the production of Transparent Exopolymeric Particles (TEP), primary production, alkalinity, calcification and particulate inorganic carbon. The dynamic model is based on unbalanced algal growth and balanced growth for bacteria as described in Van den Meersche et al. (2004). In addition, in order to adequately reproduce the observations, the model has been extended by including an explicit description of calcification, T.E.P production and an enhanced mortality due to viruses. This last process, based on a critical promiscuity between cellular hosts and viral agents, successfully contributed to reproduce the bloom extinction as observed in the mesocosm experiment. This model will be implemented in a coupled physical-biogeochemical model of the Black Sea ecosystem in the framework of the EU Sesame project and in the Gulf of Biscay in the frame of the Belgian PEACE project. [less ▲]

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See detailDynamic Modeling and control of a pilot CO2 postcombustion capture plant
Léonard, Grégoire ULg; Cabeza Mogador, Bruno; Belletante, Ségolène et al

Poster (2013, June)

A dynamic model of a post-combustion capture pilot plant is developed using Aspen Plus Dynamics. An innovative process control strategy is studied for regulating the water balance of the process. A ... [more ▼]

A dynamic model of a post-combustion capture pilot plant is developed using Aspen Plus Dynamics. An innovative process control strategy is studied for regulating the water balance of the process. A washing section where the flue gas from the absorber is washed with cold water is included to the process in order to reduce the emissions of amine to the air. Control of the water balance in the solvent loop is successfully achieved by changing the washing water temperature. In previous publications regarding CO2 capture pilot plants, the regulation of the water balance always required a water make-up flow which appears here as unnecessary. Rejection of disturbances and different load reduction scenarios are tested to confirm the efficiency of this strategy. Potential operational problems of this control strategy are identified and solved. [less ▲]

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See detailDynamic modeling and control strategies for Organic Rankine Cycle systems
Quoilin, Sylvain ULg; Lemort, Vincent ULg

Conference (2012, September 13)

Control and optimization are major issues in ORC systems applied to waste heat sources. This talk provides an overview of the current state of the art and of the main areas of R&D in that topic, including ... [more ▼]

Control and optimization are major issues in ORC systems applied to waste heat sources. This talk provides an overview of the current state of the art and of the main areas of R&D in that topic, including: - Steady-state and dynamic modeling of ORC cycles (simulation platforms, modeling paradigms, numerical issues) - Optimization of the working conditions for a given heat source and heat sink, and in particular of the evaporating temperature - Optimal start-up and shut-down strategies (grid synchronization, pressure overshoot, ...) - Control of the cycle under transient heat source conditions - Traditional and advanced controllers (PID, Model predictive control) The different adjustable working conditions (condensing/evaporating temperature, superheating, subcooling, working fluid flow rate) are listed with regard to the available degrees of freedom (pump/expander speed, secondary fluid flow rates and temperatures) and their optimal values are derived, depending on the target application. [less ▲]

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See detailDynamic modeling and control strategy analysis of a micro-scale CSP plant coupled with a thermocline system for power generation
Dickes, Rémi ULg; Desideri, Adriano ULg; Bell, Ian ULg et al

Conference (2014, September 17)

Concentrated solar power systems are characterized by strong transients and require proper control guidelines to operate efficiently. In this context, a dynamic model of a 5 kWe solar ORC system is ... [more ▼]

Concentrated solar power systems are characterized by strong transients and require proper control guidelines to operate efficiently. In this context, a dynamic model of a 5 kWe solar ORC system is developed in the Modelica language to investigate the possible advantages of coupling a concentrating solar power system with a thermocline packed-bed storage. The models of the solar field, the thermocline storage and the ORC unit are described and integrated in the open-source ThermoCycle library. A first regulation strategy is proposed and implemented into a controller unit. Results of a three-day simulation using real meteorological data are finally analyzed and discussed. [less ▲]

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See detailDynamic modeling and optimal control strategy of waste heat recovery Organic Rankine Cycles
Quoilin, Sylvain ULg; Aumann, Richard; Grill, Andreas et al

in Applied Energy (2011)

Organic Rankine Cycles (ORCs) are particularly suitable for recovering energy from low-grade heat sources. This paper describes the behavior of a small scale ORC used to recover energy from a variable ... [more ▼]

Organic Rankine Cycles (ORCs) are particularly suitable for recovering energy from low-grade heat sources. This paper describes the behavior of a small scale ORC used to recover energy from a variable flow rate and temperature waste heat source. A traditional static model is unable to predict transient behavior in a cycle with a varying thermal source, whereas this capability is essential for simulating an appropriate cycle control strategy during part-load operation and start and stop procedures. A dynamic model of the ORC is therefore proposed focusing specifically on the time-varying performance of the heat exchangers, the dynamics of the other components being of minor importance. Three different control strategies are proposed and compared. The simulation results show that a model predictive control strategy based on the steady-state optimization of the cycle under various conditions is the one showing the best results. [less ▲]

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See detailDynamic Modeling and Validation of Radiant Ceiling Systems Coupled to its Environment
Fonseca, Néstor; Cuevas, Cristian; Lemort, Vincent ULg

(2010, July)

This paper presents the results of a study performed in order to develop a dynamic model of radiant ceiling panels in heating or cooling modes coupled to its environment (fenestration, walls, internal ... [more ▼]

This paper presents the results of a study performed in order to develop a dynamic model of radiant ceiling panels in heating or cooling modes coupled to its environment (fenestration, walls, internal loads and ventilation system). The model considers the radiant panels as a dynamic-state finned heat exchanger connected to a detailed lumped dynamic model of the building (R-C network). The behavior of the radiant ceiling system and the interactions with its environment has been experimentally and numerically evaluated. Using as inputs the radiant ceiling and room dimensions, material properties and the transient measurements of air temperature at the adjacent zones, supply air and water temperatures and mass flow rates, the model allows for the estimation of the water exhaust temperature, radiant ceiling average surface temperature, resultant and dry air room temperatures, radiant ceiling power and internal surface temperatures of the room in order to compare with measurements taken during the commissioning process. Two dynamic tests in heating and cooling modes are used to validate the model. [less ▲]

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See detailDynamic Modeling andControl System Definition for a Micro-CSP Plant Coupled with Thermal Storage Unit
Ireland, Melissa; Orosz, Matthew; Brisson, John et al

in Proceedings of TurboExpo 2014 (2014)

Organic Rankine cycle (ORC) systems are gaining ground as a means of effectively providing sustainable energy. Coupling small-scale ORCs powered by scroll expander-generators with solar thermal collectors ... [more ▼]

Organic Rankine cycle (ORC) systems are gaining ground as a means of effectively providing sustainable energy. Coupling small-scale ORCs powered by scroll expander-generators with solar thermal collectors and storage can provide combined heat and power to underserved rural communities. Simulation of such systems is instrumental in optimizing their control strategy. However, most models developed so far operate at steady-state or focus either on ORC or on storage dynamics. In this work, a model for the dynamics of the solar ORC system is developed to evaluate the impact of variable heat sources and sinks, thermal storage, and the variable loads associated with distributed generation. This model is then used to assess control schemes that adjust operating conditions for daily environmental variation. [less ▲]

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See detailDynamic modeling of methylotrophic Pichia pastoris culture with exhaust gas analysis: from cellular metabolism to process simulation
Niu, H; Daukandt, M; Rodriguez, Ch et al

in Chemical Engineering Science (2013), (87), 381-392

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See detailDynamic modelling and control of a pilot plant for post-combustion CO2 capture
Léonard, Grégoire ULg; Cabeza Mogador, Bruno; Belletante, Ségolène et al

in Computer Aided Chemical Engineering (2013), 31

A dynamic model of a post-combustion pilot capture plant is developed using Aspen Plus Dynamics. An innovative process control strategy is studied for regulating the water balance of the process. A ... [more ▼]

A dynamic model of a post-combustion pilot capture plant is developed using Aspen Plus Dynamics. An innovative process control strategy is studied for regulating the water balance of the process. A washing section where the flue gas from the absorber is washed with cold water is included to the process in order to reduce the emissions of amine to the air. Control of the water balance in the solvent loop is successfully achieved by changing the washing water temperature. In previous publications regarding CO2 capture pilot plants, the regulation of the water balance always required a water make-up flow which appears here as unnecessary. Rejection of disturbances and different load reduction scenarios are tested to confirm the efficiency of this strategy. Potential operational problems of this control strategy are identified and solved. [less ▲]

Detailed reference viewed: 111 (17 ULg)
See detailDynamic Modelling, Simulation Analysis---Useful for Understanding Biology?
Bullinger, Eric ULg

Scientific conference (2005, November 11)

Detailed reference viewed: 4 (0 ULg)
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See detailDynamic MR Based Analysis of Tumor Movement in Upper and Mid Lobe Localized Lung Cancer
Kovacs; Hadjiev; LAKOSI, Ferenc ULg et al

in Pathology Oncology Research (2008)

Detailed reference viewed: 4 (0 ULg)
See detailDynamic multilevel filtering for real-time estimation of electric power systems
Mallieu, Didier; Van Cutsem, Thierry ULg; Rousseaux, Patricia ULg et al

in Control, Theory and Advanced Technology (1986), 2(2), 255-272

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See detailA dynamic neighbourhood discovery protocol for active overlay networks
Martin, Sylvain ULg; Leduc, Guy ULg

in Lecture Notes in Computer Science (2004), 2982

d-RADAR(1) is a neighbourhood discovery protocol for overlay network environments designed for (but not limited to) active network overlays. The core of the algorithm is an expanding ring-search based on ... [more ▼]

d-RADAR(1) is a neighbourhood discovery protocol for overlay network environments designed for (but not limited to) active network overlays. The core of the algorithm is an expanding ring-search based on the IP routing table content augmented with traffic-based and dynamic refreshing techniques that allows it to react to virtual topology changes (nodes joining/leaving the overlay) as well as IP topology changes (broken and repaired link, route changes and moving nodes). This paper presents how the protocol detects overlay candidate nodes using probing capsules and the algorithms needed to select neighbours among the candidates. We also show how d-RADAR keeps the neighbouring table up to date and learns topology changes while keeping a low discovery and refresh overhead. A short summary of simulations carried out with our active network simulator illustrates how these algorithms actually behave. [less ▲]

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See detailDynamic Nucleocytoplasmic Shuttling of an Arabidopsis SR Splicing Factor: Role of the RNA-Binding Domains
Rausin, Glwadys ULg; Tillemans, Vinciane ULg; Stankovic, Nancy ULg et al

in Plant Physiology (2010), 153

Serine/arginine-rich (SR) proteins are essential nuclear-localized splicing factors. We have investigated the dynamic subcellular distribution of the Arabidopsis (Arabidopsis thaliana) RSZp22 protein, a ... [more ▼]

Serine/arginine-rich (SR) proteins are essential nuclear-localized splicing factors. We have investigated the dynamic subcellular distribution of the Arabidopsis (Arabidopsis thaliana) RSZp22 protein, a homolog of the human 9G8 SR factor. Little is known about the determinants underlying the control of plant SR protein dynamics, and so far most studies relied on ectopic transient overexpression. Here, we provide a detailed analysis of the RSZp22 expression profile and describe its nucleocytoplasmic shuttling properties in specific cell types. Comparison of transient ectopic- and stable tissue-specific expression highlights the advantages of both approaches for nuclear protein dynamic studies. By site-directed mutagenesis of RSZp22 RNA-binding sequences, we show that functional RNA recognition motif RNP1 and zinc-knuckle are dispensable for the exclusive protein nuclear localization and speckle-like distribution. Fluorescence resonance energy transfer imaging also revealed that these motifs are implicated in RSZp22 molecular interactions. Furthermore, the RNA-binding motif mutants are defective for their export through the CRM1/XPO1/Exportin-1 receptor pathway but retain nucleocytoplasmic mobility. Moreover, our data suggest that CRM1 is a putative export receptor for mRNPs in plants. [less ▲]

Detailed reference viewed: 64 (33 ULg)