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A Versatile Prognostics Approach for Batteries and Hydrogen Storage Systems Health Management
No full textInternational audienceThe degradation of energy storage systems, including batteries, proton exchange membrane fuel cells, and electrolyzers, presents a critical challenge to their long-term reliability and efficiency. This study addresses the prediction of Remaining Useful Life by selecting a robust state-of-health indicator tailored to each system. A novel data-driven prognostic approach is proposed, leveraging Long Short-Term Memory neural networks to capture temporal dependencies and nonlinear degradation trends. The recurrent neural network model demonstrates versatility, adapting to both electrochemical storage and hydrogen-based systems by effectively learning from diverse datasets. Results highlight the method's capability to generalize across technologies, enabling accurate degradation predictions and offering significant insights into performance management
Ultrasound-based Condition Monitoring of Power Converters with Physics-Informed Compression
No full textInternational audienceCondition monitoring of power converters is vital but challenging due to sensor invasiveness and high computational demands. This paper introduces a non-invasive ultrasound-based approach using CNN autoencoders with a physics informed loss function for efficient data compression, outperforming traditional wavelet methods, enhancing data storage needs, and improving diagnostic feature extraction
Inclusion of Magnesium- and Strontium-Enriched Bioactive Glass into Electrospun PCL Scaffolds for Tissue Regeneration
No full textInternational audienceBioactive glass (BG) is a promising material known for its osteogenic, osteoinductive, antimicrobial, and angiogenic properties. For this reason, melt-quench-derived BG powders embedded into composite electrospun poly(ε-caprolactone) (PCL) mats represent an interesting option for the fabrication of bioactive scaffolds. However, incorporating BG into nano-/micro-fibers remains challenging. Our research focused on integrating two BG compositions into the mat structure: 45S5 and 45S5_MS (the former being a well-known, commercially available BG composition, and the latter a magnesium-and strontium-enriched composition based on 45S5). Both BG types were added at concentrations of 10 wt.% and 20 wt.%. A careful grinding process enabled effective dispersion of BG into a PCL solution, resulting in fibers ranging from 500 nm to 2 µm in diameter. The mats' mechanical properties were not hindered by the inclusion of BG powder within the fibrous structure. Furthermore, our results indicate that BG powders were successfully incorporated into the scaffolds, not only preserving their properties but potentially enhancing their biological performance compared to unloaded PCL electrospun scaffolds. Our findings indicate proper cell differentiation and proliferation, supporting the potential of these devices for tissue regeneration applications
A Novel Optimization Method for Accurate AC resistance prediction of High Frequency Transformer
No full textInternational audienceExisting methods for high frequency design have two main limitations which significantly affect the design accuracy: (1) the choice of the suitable filling factor and (2) the inaccurate prediction of the Ac resistance. This paper proposes a novel numerical method to determine an accurate estimation of the Ac resistance and avoid the need of using the filling factor in the design process. The performed experimental results are in good agreement with the developed theoretical results. The study shows that the variation of the optimal B is the inverse of the root-mean-square core volume variation
Comprehensive Analysis of High Bandwidth Converters Based on SiC Technology for Automotive and Aircraft Applications
No full textInternational audience>This paper explores the influence of semiconductor technology on the bandwidth of power converters, with a particular focus on the loss mechanisms of Silicon Carbide (SiC) MOSFETs and the non-idealities of switching cells. A model for the harmonic content as a function of switching frequency to evaluate the potential bandwidth limits based on the total harmonic distortion (THD) of the output current is introduced. Given that the relationship between bandwidth and switching frequency is directly proportional to the THD limit of the output current, it becomes crucial to investigate the temperature limitations and loss mechanisms of the components used within the switching cell to ensure a viable converter. Both simulation and experimental results are employed to verify the accuracy of loss models and evaluate the relationship between THD and switching frequency, considering ripple current, the effect of output inductance parasitic capacitance, the saturation of the magnetic core, as well as the impact of dead time
Enhanced SPICE Simulation of Inductive Component Behavior: Integrating Impedance Measurement and Core Loss Models for Transient Simulations
No full textInternational audienceThis paper presents an enhanced method to model impedance data of inductive components for accurate simulation in transient SPICE simulations by utilizing vector fitting algorithms. These models are extended by a core loss model based on the improved generalized Steinmetz equation (iGSE). Through practical measurements, we demonstrate that the resulting models closely replicate the behavior of real inductors. These results present a more precise approach to simulating inductive components, particularly in scenarios where losses play a crucial role
Innovative Flyback Transformer Design: Enhancing Efficiency and Reducing Harmonic Current
No full textInternational audienceA novel flyback transformer design reduces harmonics and improves efficiency. It use two auxiliary windings and a curved air gap. Simulations and experiments show significant improvements compared to traditional designs. Future research will focus on optimizing the design for various applications and power levels
Integration of Small Hydropower Plants into Microgrids: Overview, Control, and Modeling Challenges
No full textInternational audienceHydroelectric power is a dispatchable energy source and plays a crucial role in maintaining stability in islanded microgrids through grid-forming control. This paper presents a comprehensive overview of the modeling and control strategies for small hydropower plants (SHPs), their integration into microgrids, and their interactions with other distributed energy resources (DERs), such as solar power. The study focuses on examining key challenges related to stability, modeling, and control of SHPs to promote hybrid power integration within a microgrid. To address these challenges, recommendations for improving the performance of microgrid-based small hydropower plants are proposed, including advanced control techniques and the implementation of Hardware-in-the-Loop (HIL) simulations to enhance the accuracy of modeling, testing, and validation
Sensorless Position Control of Synchronous Reluctance Motor with Real Time Path Generation
No full textInternational audienceThis paper presents a sensorless position control for synchronous reluctance motors with real-time path generation. Sensorless control employs highfrequency flux injection with digital demodulation by sampling. The path generation is embedded in the drive microcontroller making available the use of fast feedforward actions both in the control loops and in the sensorless engine. The experimental results show the feasibility of the approach although the intrinsic position estimation error of the high-frequency injection limits the speed range
Reconfigurable single-layer air coil inductor with bistable compliant windings
No full textInternational audienceWe present an air coil with bistable compliant single layer windings. Due to stable elastic snapping deformation of wire segments, the self-inductance of the air coil can be precisely varied in multiple steps. A numerical and analytical design methodology is proposed and successfully validated by magneto-quasi-static field simulations and experiments on prototypes