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This paper investigates the potential contribution that interconnectors can provide to efficiently support the security of interconnected power systems. The proposed modelling setup introduces a radical paradigm shift in the operation of the interconnectors and in their interactions with multiple markets. To the best of our knowledge, this is the first paper that models a simultaneous allocation of the interconnector capacity for the exchange of energy and of inertia-dependent primary frequency response. The benefits and impact of this new methodology are evaluated with typical market indicators (e.g., social welfare and interconnector revenues) under two different paradigms: a centralized approach where the interconnectors are operated to minimize the system operational cost and a market-based framework where the interconnectors are privately-owned assets with self-interested objectives. By modelling the interconnectors as “price-maker”, the proposed work quantifies the potential inefficiencies of market solutions while considering key elements such as capacity withdrawing. A case study of the GB-France systems assesses the value of interconnectors on system efficiency and security under the considered paradigms. [ABSTRACT FROM AUTHOR]

The coronavirus disease 2019 (COVID-19) pandemic has urged many governments in the world to enforce a strict lockdown where all nonessential businesses are closed and citizens are ordered to stay at home. One of the consequences of this policy is a significant change in electricity consumption patterns. Since load forecasting models rely on calendar or meteorological information and are trained on historical data, they fail to capture the significant break caused by the lockdown and have exhibited poor performances since the beginning of the pandemic. In this paper we introduce two methods to adapt generalized additive models, alleviating the aforementioned issue. Using Kalman filters and fine-tuning allows to adapt quickly to new electricity consumption patterns without requiring exogenous information. The proposed methods are applied to forecast the electricity demand during the French lockdown period, where they demonstrate their ability to significantly reduce prediction errors compared to traditional models. Finally, expert aggregation is used to leverage the specificities of each predictions and enhance results even further. [ABSTRACT FROM AUTHOR]

The performance implications of entrepreneurial intensity and ambidexterity have been extensively, yet separately, examined. In addition, past research has seldom analyzed the performance implication of ambidexterity at institutional levels. Moreover, questions remain unanswered regarding the benefits that derive from the ambidextrous levels of institutional environments. To address this issue, this paper uses the concept of institutional ambidexterity, which is the balanced and simultaneous presence of both exploration and exploitation orientations that are derived from the layers of the firms’ institutional environment. A model is developed to analyze the role of institutional ambidexterity on entrepreneurial intensity and its moderating effect on the relationship between entrepreneurial intensity and firm performance. This model is empirically tested on a very large sample in the French wine context. First, the results uncover some interesting differences in the underlying drivers of entrepreneurial intensity in ambidextrous versus nonambidextrous multilayered institutional environments. Second, the results also show that entrepreneurial intensity positively influences firm performance. Finally, decomposition analyses further indicate that institutional ambidexterity moderates the influence between entrepreneurial intensity and perceptual as well as objective measures of performance. [ABSTRACT FROM AUTHOR]

This paper presents a new method for the accelerated aging tests of power semiconductor devices in photovoltaic (PV) inverters. Mission profiles are analyzed; output current and ambient temperature are extracted over several years from multiple PV plants located in France. It is then proposed to create a particular aging profile that takes into account not only the different constraints of the application of the PV inverters (high-frequency switching and sinusoidal-shaped current) but also reproduces a typical profile of the output current of PV inverters. Similarly, the ambient temperature varies as in the real application. By applying current injections with relatively long durations, the direct bonded copper (DBC) substrates and the coolers are subjected to high temperature swings. This method should shows better representation of the thermal behavior of dc/ac inverters used in PV applications, and is expected to show more representative results than traditional power cycling, thus reducing the favoring of certain failure modes to the detriment of others. [ABSTRACT FROM AUTHOR]

Conventional energy generation sources mainly provide energy supply to remote areas nowadays. However, because of growing concerns over greenhouse gas emissions, the integration of renewable energy sources is mandatory to meet power demands and reduce climatic effects. The advancements in renewable generation sources and battery storage systems pave the way for microgrids (MGs). As a result, MGs are becoming a viable solution for power supply shortage problems in remote-area applications, such as oceanic islands. In this paper, an islanded MG, which consists of PV system, tidal turbine (TT), diesel generator (DG), and Li-ion battery, is considered for Ouessant island in Brittany region in France. The economic operation of the MG is achieved by including battery degradation cost, levelized costs of energy of the PV system and TT, operating and emission costs of DG, and network constraints. The developed model leads to a non-linear and non-convex problem, which unfortunately can converge to a local optimum solution. The problem has, therefore, been relaxed and converted to a convex second-order cone model to achieve an optimal decision strategy for islanded MG operations with a global or near-global solution. Numerical simulations are carried out to prove the effectiveness of the proposed strategy in reducing the operating and emission costs of the islanded MG. It is shown that the developed convex energy management system formulation has an optimality gap of less than 1% with reduced computational cost. [ABSTRACT FROM AUTHOR]

The monitoring of land cover requires that stable land cover classes be distinguished from changes over time. Within this paper, a postclassification method is presented that provides land cover change information, based on a time series of land cover maps. The method applies a kernel filter to sequential land cover maps. Under some basic assumptions, it shows robustness against classification errors. Despite seasonality, land cover changes often occur at a low temporal frequency (e.g., maximum once every 5–10 years). If land cover maps are available more frequently, some of the information will become redundant (oversampling). The proposed method uses this redundancy for tolerating (nonsystematic) misclassifications. In order to demonstrate the benefits and limitations of the proposed method, analytical expressions have been derived. When compared to a simple postclassification comparison, one of the key strengths of the proposed approach is that it is able to improve both the overall and user's accuracy of change, while also maintaining the same level of producer's accuracy. As a case study, MODerate Resolution Imaging Spectroradiometer remote sensing data from 2006-2010 were classified into forest (F)/nonforest (NF) at pan-European scale. Promising results were obtained for detecting forest loss due to natural disasters. Quality was assessed using burnt area maps in southern Europe and a forest damage report after a windstorm in France. Results indicated a considerable reduction of change detection errors, confirming the theoretical results. [ABSTRACT FROM PUBLISHER]

This paper outlines the process and procedures adopted to design the architecture and functional requirements of instrumentation and control (I&C) based on IEC 61850 standards. The I&C system of the electrical power distribution network will conform to the standards, specifications, and interfaces as set down by the ITER Organization and applied by suppliers in domestic agencies. The IEC 61850 system will ensure the reliable smooth operation and maintenance of the ITER electrical control system at Cadarache, France. [ABSTRACT FROM PUBLISHER]

The hardware commissioning of the Large Hadron Collider required the testing and the qualification of the cryogenic and vacuum system, as well as the electrical systems for the powering of more than 10 000 superconducting magnets. Nonconformities had to be resolved within a tight schedule. In this paper, we focus on the role that electromagnetic-field computation has played during hardware commissioning in terms of the analysis of a magnet quench and electromagnetic-force calculations in busbars and splices, as well as field-quality prediction for the optimization of powering cycles. [ABSTRACT FROM AUTHOR]

Superconducting magnets can exhibit training quenches during successive powering to reaching nominal performance. The slip–stick motion of the conductors is considered to be one of the mechanisms of training. In this paper, we present a simple quantitative model where the training is described as a discrete dynamical system matching the equilibrium between the energy margin of the superconducting cable and the frictional energy released during the conductor motion. The model can be explicitly solved in the linearized case, showing that the short sample limit is reached via a power law. Training phenomena have a large random component. A large set of data of the large hadron collider magnet tests is postprocessed according to previously defined methods to extract an average training curve for dipoles and quadrupoles. These curves show the asymptotic power law predicted by the model. The curves are then fit through the model, which has two free parameters. The model shows good agreement over a large range, but it fails to describe the very initial part of the training. [ABSTRACT FROM AUTHOR]

Superconducting cables for power transmission usually contain two conductors for DC application, or three conductors for AC, with high voltage insulation. In contrast, for some applications related to accelerators it is convenient to transfer high currents via superconducting links feeding a number of circuits at relatively low voltage, of the order of a kilovolt, over distances of up to a few hundred meters. For power transmission applications based on cooling via sub-cooled liquid nitrogen, suitable HTS conductors are only available in the form of tape, and a multi-layer variant can be envisaged for the multi-circuit links. However, where cooling to temperatures of the order of 20 K is feasible, MgB2 conductor, available in the form of both tape and wire, can also be envisaged and in the latter case used to assemble round cables. There are, therefore, two distinct topologies—based on the use of wires or tapes—that can be envisaged for use in applications to multi-circuit link systems. In this paper the merits of the two approaches are compared, and case studies related to applications to the LHC are presented. [ABSTRACT FROM AUTHOR]

The Facility for Anti-proton and Ion Research (FAIR), under development at GSI, includes the synchrotron SIS300, so called because the magnetic rigidity is 300 Tm. In order to reach the required high intensities of proton and heavy ions beams, the bending dipole magnets have to be pulsed from the injection magnetic field of 1.5 T up to 4.5 T maximum field at the rate of 1 T/s. These 7.8 m long magnets have \cos\theta shaped coils with a 100 mm bore and the particular characteristic to be geometrically curved, with a sagitta of 112.9 mm. These challenging requirements triggered R&D activities, aimed at the development of suitable construction technologies for fast ramped curved coils. The heart of the R&D program is the construction of a 3.9 m long model. The paper discusses the main problems faced during the design and the construction of the cold mass, mainly covering the aspects related to the manufacture. [ABSTRACT FROM AUTHOR]

Future upgrades of the Large Hadron Collider (LHC) will require large aperture and high gradient quadrupoles. Nb3Sn is the most viable option for this application but is also known for its strain sensitivity. In high field magnets, with magnetic fields above 12 T, the Lorentz forces will generate mechanical stresses that may exceed 200 MPa in the windings. The existing measurements of critical current versus strain of Nb3Sn strands or cables are not easily applicable to magnets. In order to investigate the impact of high mechanical stress on the quench performance, a series of tests was carried out within a LBNL/CERN collaboration using the magnet TQS03 (a LHC Accelerator Research Program (LARP) 1-meter long, 90-mm aperture Nb3Sn quadrupole). The magnet was tested four times at CERN under various pre-stress conditions. The average mechanical compressive azimuthal pre-stress on the coil at 4.2 K ranged from 120 MPa to 200 MPa. This paper reports on the magnet performance during the four tests focusing on the relation between pre-stress conditions and the training plateau. [ABSTRACT FROM AUTHOR]

The accident in the LHC in September 2008 occurred in an interconnection between two magnets of the 13 kA dipole circuit. Successive measurements of the resistance of other interconnects revealed other defective joints, even though the SC cables were properly connected. These defective joints are characterized by a poor bonding between the SC cable and the copper stabilizer in combination with an electrical discontinuity in the copper stabilizer. A quench at the 7–13 kA level in such a joint can lead to a fast and unprotected thermal run-away and hence opening of the circuit. It has therefore been decided to operate the LHC at a reduced and safe current of 6 kA corresponding to 3.5 TeV beam energy until all defective joints are repaired. A task force is reviewing the status of all electrical joints in the magnet circuits and preparing for the necessary repairs. The principle solution is to resolder the worst defective joints and, in addition, to apply an electrical shunt made of copper across all joints with sufficient cross-section to guarantee safe 12-13 kA operation at 7–7.5 TeV. In this paper the various actions that have lead to this solution are presented. [ABSTRACT FROM AUTHOR]

The test of the first LARP(LHC Accelerator Research Program) Long Quadrupole is a significant milestone toward the development of Nb3Sn quadrupoles for LHC (Large Hadron Collider) Luminosity Upgrades. These 3.7-m long magnets, scaled from the 1-m long Technological Quadrupoles, are used to develop our capabilities to fabricate and assemble Nb3Sn coils and structures with lengths comparable to accelerator magnet dimensions. The long quadruples have a target gradient of 200 T/m in a 90-mm aperture. Pre-stress and support are provided by an Al-shell-based structure pre-loaded using bladders and keys. The coils were fabricated at BNL and FNAL, the shell-based structure was designed and assembled at LBNL, the test is performed at FNAL. In this paper we present the final steps of the development of the first model (LQS01), several upgrades to the test facility, the test results of witness cables, and the short sample limit. [ABSTRACT FROM AUTHOR]

In the framework of the US LHC Accelerator Program (LARP), three US laboratories BNL, FNAL and LBNL are developing Nb3Sn quadrupole magnets for the Large Hadron Collider (LHC) luminosity upgrade. At present CERN is supporting this activity by testing some of the LARP 1 m long 90 mm aperture magnets. Recently two magnets using a shell based key and bladder technology (TQS) have been tested at CERN. These magnets (TQS02c, TQS03a) share the same mechanical structure and use a 27 strand Rutherford cable based on the 0.7 mm RRP strand. The main difference between the two magnets is the strand sub-element layout (54/61 in TQS02c versus 108/127 in TQS03a) and the strand critical current. The TQS03a wire has a lower (18%) critical current, a larger amount of copper stabilizer, and a larger number of superconducting sub-elements with respect to the TQS02c strand. The tests show that TQS02c was stable between 4.3 K and 2.7 K while it was limited by the self-field instability at lower temperatures. TQS03a was not limited by magneto-thermal instabilities and reached 93% of the short sample limit both at 4.3 K and 1.9 K. In this paper the results are summarized and compared with the stability measurements performed at CERN on individual strands. [ABSTRACT FROM AUTHOR]

Study of a wind-energy-conversion system (WECS) is a very attractive topic for students. The analysis of an entire WECS requires knowledge of different scientific fields, which are of interest for future engineers. In this paper, energetic macroscopic representation is used to describe a complete WECS. This synthetic graphical tool yields a natural decomposition of the studied WECS with respect to physical laws. Moreover, a control scheme is easily deduced from this description using inversion-based rules. Thus, maximum-power point-tracking strategies and drive controls can be defined. The simulation of the studied WECS is directly transposed to MATLAB-Simulink. Moreover, a hardware-in-the-loop simulation of the WECS is studied using an actual induction generator. and an electrical drive to simulate the wind turbine. This graphical methodology is used in the electrical engineering Masters degree at the University of Lille (France). [ABSTRACT FROM AUTHOR]

Recent studies of passive L-band observations over forests have shown that the average canopy transmissivity in temperate coniferous and deciduous forests is on the order of 0.4-0.5. Although the canopy would therefore be expected to transmit a reasonable amount of ground emission, the total emission observed above the canopy shows very little variation with varying soil moisture content. Moist litter present on the forest floor is known to obscure the soil emission. Therefore, more knowledge on the L-band radiative properties of litter and understory layers is needed to better understand the emission of the whole forest system. In order to contribute toward this issue, a field experiment was conducted in a pine forest in southwest France. Radiometric observations were done on the canopy and on different configurations of the forest floor, following sequential stripping of each forest floor layer. In combination with a long-term data set of abovecanopy observations, this resulted in emissivity values of bare soil, soil-litter, soil-litter-grass, and soU-litter-grass-canopy configurations for a range of soil and litter moisture values. Calculations involved the use of the Wilheit and L-MEB models. The sensitivity to soil moisture was found to be substantially suppressed by the presence of a grass understory and litter. This corroborates the low correlation between sdil moisture and L-band brightness temperature measured above the canopy. Several results of recent modeling and laboratory studies are also confirmed by this paper, which is, to our knowledge, the first to use in situ experimental data in this context. [ABSTRACT FROM AUTHOR]

The low-β triplets of the Large Hadron Collider were designed and constructed by a world-wide collaboration officially formed in 1998. Over the course of the following years the collaboration worked to produce the triplet components, including four 215 T/m, 70 mm aperture quadrupoles, a DFBX distribution feedbox, and at the low luminosity interaction points a cold Dl beam separation dipole. In 2005 the first triplet was installed in the LHC tunnel, and at the end of 2007 hardware commissioning of the first triplets started. As of August 2008 five triplets have been successfully powered. This paper documents the processes and experience gained during the commissioning phase of the LHC. [ABSTRACT FROM AUTHOR]

IRFU/SACM at CEA/Saclay has undertaken an R&D program on Nb3Sn aimed at designing, building and testing a 1-m-long, 56-mm-single-aperture quadrupole magnet model. Model design is based on the design of LHC arc quadrupole magnets, without iron yoke. It is expected to reach a nominal field gradient of 211 T/m at 11,870 A. The main goal of the program is to learn about Nb3Sn technology and evaluate fabrication techniques relative to the use of this superconductor. Coils are manufactured by the so called "wind, react and impregnate" technique. Laminated, austenitic steel collars are locked around the coil assembly by means of keys in order to restrain Lorentz forces. Coil manufacturing and magnet assembly have been achieved in 2007. Cold mass assembly is under work. Warm field measurements are carried out at each step of magnet and cold mass assembly. After a brief recall of the conceptual design, the paper reviews the manufacturing of the coils and of the magnet assembly and presents the results of warm magnetic field measurements. [ABSTRACT FROM AUTHOR]

The 3.7 m long quadrupole magnet LQS01 represents a major step of the US LHC Accelerator Research Program (LARP) towards the development of long Nb3Sn accelerator quadrupole magnets for a LHC Luminosity upgrade. The magnet support structure is a scale up of the 1 m long Technology Quadrupole TQS design with some modifications suggested by TQS model test results. It includes an aluminum shell pre-tensioned over iron yokes using pressurized bladders and locking keys (bladder and key technology). The axial support is provided by two stainless steel end plates compressed against the coil ends by four stainless steel rods. The structure, instrumented with strain gauges, has been fabricated and assembled around four aluminum "dummy coils" to determine pre-load homogeneity and mechanical characteristics during cool-down. After presenting the main magnetic and mechanical parameters of LQS01, we report in this paper on the design, assembly, and test of the support structure, with a comparison between strain gauges data and 3D finite element model results. [ABSTRACT FROM AUTHOR]

Laser Mégajoule (LMJ) is a laser facility being built by the French nuclear science directorate, Commissariat a l'Energie Atomique. This facility is a large fiashlamp pumped laser (1.8-Mi optical output). The Pulsed Power Conditioning System of LMJ is based on a modular design of 480 modules (400-MJ energy capacitor bank). A new capacitor bank module (CBM) for the LMJ Power Conditioning System has been developed by the Institute of High Current Electronics (IHCE, Tomsk) in collaboration with International Technologies for High Pulsed Power (France). Two such modules were produced and tested in IHCE. The main parts of the CBM are the following: high-voltage power supplies, command control system, air conditioning system, capacitor block, and cables delivering the energy to a load. The parameters of the module are the following: total rated capacitance of 2900 (+4%) μF, charging voltage up to 24 kV, peak current amplitude of 240 kA, peak stored energy up to 864 kJ, pulsewidth at 10% of peak power of 360 μs, dimensions of 2.3 × 1.5 × 2.5 m3, and weight of ∼2500 kg. In nominal regime (24-kV charging voltage, 40-m length cables), the energy delivered to fiashlamps in each channel is 74 kJ (86% efficiency). No failures were observed in more than 1000 test shots, and all parameters of the CBM are well within the requirements. Detailed description of the module design, performance, and test results are stated in this paper. [ABSTRACT FROM AUTHOR]

A good representativeness of the test setup used for the qualification of solar arrays is fundamental. We know now that the fiashover current involved in the electrostatic discharge is related with the total dielectric surface neutralized during the electrostatic discharge. This paper presents experiments on samples of different sizes, performed in a large vacuum chamber, JONAS, installed in ONERA/DESP, Toulouse, France. The samples are tested in the inverted voltage gradient configuration obtained with electrons. We observed that secondary arcs obtained on a large sample (i.e., with a long fiashover) had much longer durations than those on a small sample, i.e., the flashover is a critical parameter for secondary arc initiation and sustainment. [ABSTRACT FROM AUTHOR]

European Remote Sensing satellite (ERS) ENVISAT coherence is a new repeat-pass interferometric synthetic aperture radar product characterized by a very short repeat-pass interval between acquisitions (28 mm). In this paper, we investigate the properties of two 28-mins coherence images acquired over the regions of Paris, France, and Prague, Czech Republic, as well as a 35-day coherence image from Prague. Bare soils showed higher coherence compared to forests and urban areas. The range of coherence was larger for 28-mm pairs, perpendicular baseline closer to 2 km, and stable weather conditions between acquisitions. Coherence modeling shows that because of the long baseline: 1) significant surface decorrelation occurs when slopes are not accounted for in the common-band filtering and for variation of topography in the resolution cell and 2) volume decorrelation is significant. Temporal decorrelation seems to be relevant for vegetation even at the 28-mm interval time scale. Observations and modeled coherence were found to be in good agreement. Land cover classification using coherence and backscatter has been tested for the Paris scene for mapping the four major classes. The classification accuracy was 86% when an edge-eroded version of the reference land cover map was used. It decreases to 68% when the full land cover map was used as reference because of local mismatches between the coherence image and the land cover map, and the reduced common band in range. The high coherence difference between forests and bare fields suggests the possibility to use the ERS-ENVISAT coherence for forest/nonforest mapping and estimation of biophysical properties of short vegetation. [ABSTRACT FROM AUTHOR]

A new watt balance project is now in progress at the Bureau National de Métrologle (BNM), Paris, France. In this paper, the general configuration and the main parts of the experimental setup currently in development are presented. The aim is to contribute to the international effort in monitoring the kilogram toward a new definition of the mass unit with a relative accuracy of 10-8 or better. [ABSTRACT FROM AUTHOR]

The article presents information on the 2003 IEEE Geoscience and Remote Sensing Society's (GRS-S) Awards that were presented at the IGARSS'03 banquet on July 24 at Hotel Dieu in Toulouse, France. Charles Luther, the president of the society, presented those awards with the assistance of the Awards Committee Chairman Werner Wiesbeck. The award ceremony was started with the recognition of the IEEE Fellows who have declared the GRS-Society as their home society. The GRS-S Transactions Editor, based on recommendations of associate editors and reviewers, compiled the list of nominees for the Transactions Prize Paper Award.

This paper presents an original algorithm that uses a new modeling approach of the interference constraints and uses a probabilistic taboo search algorithm to solve the frequency assignment problem in the field of broadcasting. The results obtained by our algorithm are compared to the operating solutions in the field of FM broadcasting in France and the best known results obtained by hybrid genetic algorithm [2] that uses a classical modeling of the interferences constraints. By analyzing the results obtained by our approach we can observe that we efficiently enhance the quality of the solutions. [ABSTRACT FROM AUTHOR]

The article focuses on the topics of the issue dedicated to the microwave theory and techniques from the papers presented at the 35th European Microwave Conference in Paris, France. The event received a submission of 711 papers from 49 countries, in which 452 papers were accepted for presentation at the conference. The authors state that the technical contents of the papers published in the issue may help those who are concerned about microwave theory and techniques.

Editorial. Focuses on the 20th International Symposium on Discharges and Electrical Insulation in Vacuum held in Tours, France in July 2003. Number of papers presented in the conference; Lessons learned from writing about vacuum insulation.

Presents information on the Symposium on Electromagnetic Launch Technology sponsored by the U.S. Army in Saint-Louis, Paris, France on May 14 to 17, 2002. Speakers of the symposium; Papers selected for the Best Poster Presentation; Efforts of the U.S. Navy to launch aircraft from carriers.

Provides information on the European Conference on Universal Multiservice Networks held on October 2-4, 2000 in Colmar, France. Topics discussed; Number of papers presented in the conference.