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Assessment of lung parenchymal elasticity in smokers using magnetic resonance elastography and oscillometry
No full textInternational audienceContext: Smoking progressively damages the lungs through chronic inflammation, airway remodeling, and alveolar destruction. Early detection is key to slowing or preventing irreversible decline. Aim:To measure the lung parenchymal shear modulus using Magnetic Resonance Elastography (MRE) [1-2] and to compare it to the area AX of the reactance curve, measured by oscillometry in smokers.Methods: Thirty smokers (mean age 52.0±8.2 years, 21 women) referred for lung CT imaging (Fig. 1A) were prospectively recruited at the radiology department (ACRIM) (#A01496-33-MS) after informed consent. MRE is based on the analysis of the shear wave velocity, which varies with the shear modulus of the tissue. MRE was performed with a 1.5 T MRI machine (GE) using a fast gradient echo sequence. Oscillometry (TremoFlo C100, Thorasys) was performed on the same day as MRE following the ATS/ERS technical recommendations. Results:A personalized 2D map of shear modulus in right lung was obtained for each subject (Fig. 1B). A significant Spearman correlation (℘=0.36, P=0.050) was found between the shear modulus and AX parameter. Conclusion:Preliminary results show that MRE appears as a promising method to detect regional lung parenchymal properties in subjects at risk of tobacco-induced lung diseases.</div
Design Considerations and Validation of a GaN e-HEMT-Based Cryogenic Power Converter
No full textInternational audienceAs efforts to reduce CO 2 emissions grow, cryogenic power electronic converters are gaining attention for applications in electric propulsion, aerospace, and superconducting technologies. This paper presents the design and experimental validation of a power converter using GaN enhancement-mode high electron mobility transistors (e-HEMTs) optimized for cryogenic environments. Losses and efficiency are compared at room temperature (RT) and cryogenic temperature (CT), highlighting the influence of temperature on device characteristics and converter performance. Results show significant loss reductions at CT, with air cooling for RT testing and liquid nitrogen for CT experiments. These findings demonstrate the viability of GaN e-HEMT-based converters in cryogenic applications
2D FEM Modeling Comparison of Multi-Winding Magnetic Couplers for Power Electronics Applications
No full textInternational audienceMultiple-Active Bridge (MAB) converters, an extension of Dual-Active Bridge (DAB) converters, have emerged as a promising approach for multi-source, multi-load energy exchanges. A critical factor in their performance is the design of the multi-windings magnetic coupler, which determines the equivalent inductances and consequently the power flow between ports. This paper presents 2D FEM modeling techniques for multi-windings magnetic couplers, comparing various geometries models to balance precision and speed. The air gap-free FEM geometry reduces simulation time while maintaining accuracy, whereas the two stretched models involve a trade-off between precision on electrical model parameters
State-of-Health (SOH) and State-of-Charge (SOC) Estimation for Lithium-ion Battery under Fast-Charging Conditions
No full textInternational audienceThis paper presents two models for lithiumion battery SOC and SOH estimation using a Toyota Research Institute dataset. A Random Forest Regressor predicts SOH after 10 cycles, while an LSTM neural network estimates real-time SOC. Both models show high accuracy, contributing to advanced health-aware energy management in electric vehicles
High temperature characterizations of a monolithic 900 V GaN power device for current source inverter applications
No full textThis work has been realized with the participationfrom members of INES.2S.International audienceBased on the recent works [1-4] on the current source inverter for photovoltaic (PV) application with Silicon Carbide (SiC) devices, this work presents the design and the characterizations of a monolithic GaN (Gallium Nitride) device where the GaN transistor and the diode in series connection are built up on a single chip for a specific current source inverter topology. This work presents the details of this monolithic 900 V GaN device in the first section, and then the static characterizations by using of an automatic industrial equipment (B1506 from Keysight) with a high temperature thermostream will be shown in the second section. A specific double pulse test-bench is detailed for high temperature dynamic characterization with the high speed current and voltage probes, this monolithic GaN device can be heated-up locally up to 175°C by using an infrared beam station
An overview of grid code possible requirements for an interoperability MVAC/MVDC systems -Focus on fault detection for a future PV power plant
No full textInternational audienceAn AC/DC interoperability is expected to be part of the future grid but is not currently developed at medium voltage level. Standardization efforts are necessary to develop medium voltage DC (MVDC) systems. This article discusses the existing grid code for medium voltage (MV) applications, providing an overview of the existing requirements and the future requirements expected for the development of MVDC applications. Behaviour of a hybrid AC/DC system during fault situations through PLECS based simulation has been provided
Analysis, Modulation and Control of a Ground Power Unit for Aircraft Applications
No full textInternational audienceThis paper presents a PLECS-based simulation of innovative AC-AC converter configurations tailored for Ground Power Units (GPUs), addressing the critical demand for airport electrification, a cornerstone of sustainable aviation and ground operations. The proposed design incorporates a Current-Synthesized Power Factor Correction (CSPFC) rectifier, operating with a suitable harmonic injection technique, and proper modulation strategies. Simulation results demonstrate the system's effectiveness in mitigating issues such as harmonic distortion, voltage ripple, and other operational challenges, underscoring its potential to enhance performance and sustainability in GPU applications
A Cost-Effective Three Level Shared Leg Flying Capacitor Converter for Switched Reluctance Motors
No full textInternational audienceThis paper presents a novel, cost-effective multilevel inverter for switched reluctance motor (SRM) drives. The proposed inverter has a threelevel topology with shared-leg flying-capacitor (SLFC) structure. This topology utilizes two shared legs for adjacent phases during the magnetization, freewheeling, and demagnetization of the SRM. This innovative approach reduces the drive's size and cost by reducing the number of power switches, diodes, gate drivers, current and voltage sensors while achieving the same performance as the conventional three-level flying capacitor topology. In comparison to the conventional asymmetric half bridge converter, it improves the performance in terms of current ripple and reduces the voltage stress of some of semiconductors. The feasibility of the proposed three-level SLFC topology is verified through simulation studies based on a three-phase 12/16 SRM drive system
Compact Interoperable DC Charging Station Enabling Smart Charging Features for e-Bike Charging Park
No full textInternational audienceThis paper proposes a 1.5 kW rated compact, interoperable DC charger system with smart charging strategies for e-Bike charging parks. The necessary data monitoring unit, open charge point protocol (OCPP 1.6j) hardware unit, EnergyBus protocol compatible charging ports, and power protection devices are incorporated into the proposed system
Review of Multiport Energy Router Structures in the Specific Context of Wind Power Generation Systems
No full textInternational audienceThe recent trend of using a multiport machine as an energy router has appeared and become an attractive solution in drive-included applications like wind turbines. This paper provides a review of multiport converters and machines, their integration in a wind generation system is evaluated. Then, a novel energy router structure based on the highly coupled multiport machine is proposed. The energy router enables energy storage integration in the wind turbine generation system. A power control scheme is implemented, and simulation results show that the multiport machine energy router can achieve similar power regulations of a standard DC coupled energy router