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Quantifying Incomplete Zero-Voltage Switching Losses Using Equivalent Hard-Switching Losses
No full textInternational audienceWith fast switching wide band-gap semiconductors conquering high-power application, zerovoltage switching (ZVS) topologies are crucial to increase converter efficiency by minimizing switching losses. However, ZVS criteria cannot always be fulfilled in the entire operating range of the converter. In this case, the converter enters incomplete ZVS (iZVS). The losses during iZVS cannot be quantified using conventional double-pulse tests, but require calorimetric measurement setups, and separation of turn-on, conduction, and turn-off losses. This can be obtained for discrete devices, but is not possible for power modules. In this paper, a method to estimate the switching losses during iZVS using equivalent hard-switching losses is presented and experimentally verified, allowing to quantify the losses in power modules
Analysis of Imbalance in Input-Series Output-Parallel Configuration of Series Resonant Converters
No full textInternational audienceThis paper analyses the power imbalance in input series output parallel (ISOP) configurations of series resonant converters (SRC), which are crucial for MVDC to LVDC conversion where electrical isolation and bidirectional operation are required. The dual active bridge (DAB)-based ISOP structure presents a promising solution, but it requires careful management of power distribution among modules to prevent imbalances. This study provides analysis on imbalance among SRC modules for a partial power control method, which contributes to reducing communication costs and complexity by minimizing the number of active control modules. Experimental results with two prototype SRC modules validate the theoretical analysis, demonstrating that power imbalances are negligible in the ISOP configuration
Atelier 2 - Encodage et annotation du texte: Atelier "Créer une édition scientifique numérique"
No full textPrésentation pour l'atelier ObTIC du 14 mars 2025 "Encodage et Annotation de texte" de la série d'ateliers "Créer une édition scientifique numérique"Ce second atelier est dédié à l’encodage de texte en XML-TEI, le standard utilisé de nos jours pour encoder des textes littéraires. Après une introduction au langage de balisage XML et aux composants du standard TEI, les participants procéderont aux travaux pratiques, avec l’encodage des métadonnées, du corps du texte, ainsi que de diverses annotations (sémantique, critiques, etc.) pertinentes pour le corpus travaillé
Values Change, So Does Philosophy of Technology and Engineering
No full textThe aim of this first chapter is to introduce the current Philosophy of Engineering and Technology volume Engineering and Changing Values, and explain its origin, originality, and purpose. While growing out of a meeting of the forum on Philosophy, Engineering, and Technology (fPET) held in Delft in 2023, its final form is the fruit of a singular editorial, selection and support effort. This introductory chapter aims to highlight its singularity, which is based as much on the theme addressed as on the geographical, cultural, and disciplinary diversities that characterize the group of contributors, and the editorial team, which is in the image of the forum from which it comes. This chapter also describes the general philosophy of the book and the four thematic sections that make it up: ethics, justice, epistemology, and theoretical approaches to value change in design. This introduction also provides an opportunity to thank the many people who helped make this project a reality
A comparison of lithium diffusion between Graphite/LFP 18650 power and energy cells with low and high current pulses
No full textInternational audienceThis study gives a new estimation model to evaluate the voltage-increase due to a step-up current in both lithium-ion power and energy cells. The step-up current analysis is similar to the GITT technic developed in the literature, but with tests at low or high C-rate and for a longer time. The power cell voltage-increase follows a square root of time dependency which is commonly observed in the literature. On the contrary, a superimposed transient overvoltage in the energy cell is observed. The transient overvoltage has the capacity to distort the characterization of diffusion as modelled by existing models. This paper proposes a phenomenological approach to model the transient overvoltage in the energy cell. This work gives a method to model thephenomenon and is a first step to clarify the originof the phenomenon. It can also help improving theestimation of the diffusion parameters
Improved Energy Management Strategy for Minimizing Capacitors Storage in Power Converters for Particle Accelerators
No full textInternational audienceThis study presents a new energy management strategy for electromagnetic loads supplied by power electronic converters with integrated energy recovery capability. It aims to minimize the energy storage requirements of the power converters, thereby reducing their cost and volume. The study covers a theoretical analysis, verified by simulation and experimental results
Pd/Pt bimetallic nanoparticles as catalysts in the green synthesis of piconjugated materials for perovskite solar cell applications
No full textInternational audienceThanks to their unique properties (improved volume-to-surface ratio compared to heterogeneous catalysts, highcatalytic performance and selectivity…), nanocatalysts[1] are increasingly used for environmental remediation[2] toremove organic pollutants as well as for oxidation-reduction processes and C-C couplings in organic synthesis.[3]Pi-conjugated molecules, which are employed for electronic organic applications, are heavily reliant on palladiumcatalyzed C-C or C-heteroatom couplings for their preparation. Traditional conditions for the catalytic steps usuallyinvolve high metal loadings, harmful solvents, and long reaction times at high temperatures.[4,5,6] To improve theenvironmental footprint of the preparation of these materials and the devices in which they are applied,nanocatalysis is a very valuable tool.We prepared novel Pd/Pt bimetallic nanoparticles stabilized by a bisphosphonic ligand. The nanoparticles wereevaluated in classical Suzuki and Sonogashira coupling reactions. They showed a high catalytic activity and couldbe used in green conditions: low catalyst loading, green solvent, and short reaction time under microwaveactivation. These new nanocatalysts were then applied to the preparation of pi-conjugated materials by the Suzukicoupling of a dibenzofuran or dibenzothiophene core with triarylamine moieties (Figure 1). These pi-conjugatedmaterials were studied as efficient hole transporting materials (HTM = materials that can extract the positive chargethat appears after a photon absorption) in perovskite solar cells (Figure 2).[7
Data-Driven RUL Estimation for DC-Link Capacitor in Ultra-Fast EV Charging Systems
No full textInternational audienc
Dual Coupled Inductor-Based Current-Fed Dual-Active-Bridge Converter
No full textInternational audienceThis paper presents a dual coupled inductor current-fed DAB converter. The introduction of the CIs enhances power transfer capability, reduces the input current ripple and filter size, increases the voltage gain, and expands ZVS the region through proper circuit design. Experimental results are provided to validate the theoretical analysis and performance of the proposed converter
Modelling and Post-Fault Current Control Strategy for Multi-Three-Phase Machines
No full textInternational audienceThe growing development of Multi-Three-Phase Machines (MTPM) as competitive to conventional three-phase machines has attracted more attention to the higher reliability and fault-tolerant capability of the electrical drives system especially for safety-critical applications. In this paper, modelling technique and post-fault current control strategy for dual three-phase Interior Permanent Magnet (IPM) synchronous machines are presented, utilizing the Vector Space Decomposition (VSD) algorithm. As the multi-stator (MS) or dq modelling is an ideal option for post-fault strategies, the comparative study between VSD and MS methods are demonstrated in order to analyse their dynamic performance in nominal and faulty conditions. This take into account the equivalent harmonic inductance variation, which is then used to introduce the postfault control strategy. A double three-phase IPM machine is modelled and operated in two different operating conditions: nominal and one three-phase set of windings in open-circuit (OC). In OC fault, the proportional and integral (PI) controllers are re-designed while adapting the inductance variation. The current dynamics responses are analysed in both healthy and faulty conditions by means of Matlab/Simulink ® simulations