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A K-nearest Neighbours Inspired Direct MPC for SOC Balancing in Smart Batteries
No full textInternational audienceLithium-ion batteries dominate energy storage systems. Working circumstances and parameter variations in single cells can result in state of charge imbalances that reduce the battery's lifetime. Modular batteries have been proven to be capable of actively reducing the imbalance among the cells by connecting or bypassing the individual batteries, sharing the work load in real-time. This paper presents a machine learning-inspired direct model predictive control for reconfigurable batteries to balance the cells that solves the underlying optimization problem in polynomial time
Improving thermal management of SiC MOSFET through cold plates and/or power modules optimization
No full textInternational audienceAn experimental and numerical investigation on the impact of internal heat spreader and optimized cold plate for cooling SiC power module is presented. Silver-diamond (AgD) composites are used as heat spreaders under the SiC chips, while the cold plates are fitted with specific geometries to enhance convective heat transfers. This study is conducted for a flow regime varying from 500 < Reynolds < 8000. Thermal results show that the use of heat spreaders induces a 20% reduction of Rth(j-a). Similarly, an optimized cold plate design would reduce the cold plate thermal resistance by more than 55%. The study demonstrates that the heat spreader efficiency is better in the case of the use of an optimized design cold plate
Construction and Application of a Five-Level Inverter for Maximum Power Point Tracking (MPPT) of the Photovoltaic Systems (PV)
No full textInternational audienceConsidering the high initial cost of a solar system, achieving maximum power output is crucial. In this paper, the Nemo conduction method is utilized to reach the maximum power point of an 80W solar module. This method is also used to supply power to an Ohmic inductor load from a five-level inverter with an active diode barrier at the output of a boost converter. With this setup, a two-level five-level inverter has been developed, and a predictive control method is employed to regulate the inverter, resulting in a five-level waveform at the output. The predictive control simulation successfully generates a five-level three-phase voltage while ensuring that the output current closely tracks the reference current and the voltage of the floating capacitors is controlled. The construction and simulation results demonstrate the accuracy and speed of locating the optimal point to maximize energy production
Analysis of optimization techniques applied to the DAB converter
No full textInternational audienceThis paper compares computational approaches for optimizing DAB converters, focusing on efficiency and loss minimization. Additionally, a comparison between Single Phase Shift (SPS) and Extended Phase Shift (EPS) modulations was performed. The applied optimization techniques applied include Particle Swarm Optimization (PSO), Genetic Algorithm (GA), and Fmincon Global Search, all converging to the same optimal solution, differing only in processing time. A 2 kW prototype, with parameters obtained from the optimization for both EPS and SPS modulations, underwent testing for different voltage gains
A Comparative Study of Genetic Algorithm and Particle Swarm Optimization for Hybrid Renewable Systems with Battery and Hydrogen System
No full textInternational audienceThis paper presents a comparative study of Genetic Algorithm (GA) and Particle Swarm Optimization (PSO) for optimal sizing of two hybrid renewable energy systems: Solar with Battery and Grid, and Solar with H2 System and Grid. Real-time energy consumption data from a university is used to model these systems, aiming to minimize costs while meeting energy demands and ensuring reliability. The performance of GA and PSO is compared based on solution quality, convergence speed, and computational efficiency. Results show that GA provides robust configurations, while PSO offers faster convergence. These findings support efficient and practical hybrid system design
A Real-time Condition Monitoring Technique for SiC MOSFET Gate Oxide Degradation Based on Turn-Off Delay Time Interval
No full textInternational audienceGate oxide degradation can be regarded as one of the major categories of chip-related reliability issues in Silicon Carbide MOSFETs. This paper proposes an online condition monitoring technique (CMT) based on turn-off delay time as a precursor for gate oxide degradation. The method is real-time and does not need any change into the device's normal operation. The experimental results showed the proposed technique can provide a high-resolution assessment of the gate oxide degradation level of the device
Single-phase single-stage bidirectional PFC converter utilizing monolithic GaN bidirectional switches
No full textInternational audienceThis article presents a comprehensive study on a bidirectional, single-phase, single-stage converter for Electric Vehicle (EV) charging applications. A converter topology providing galvanic insulation between the grid and the battery with Power Factor Correction (PFC) capabilities has been proposed. By utilizing new GaN transistors with bidirectional voltage blocking capabilities, the proposed converter topology allows for a reduction in the number of transistors, leading to a significant simplification of the converter in comparison to other state-ofthe-art solutions. The system is successfully validated in a simulation study
Reconstitution virtuelle de la base crânienne du Sinanthrope (Homo erectus pekinensis
No full textInternational audienceSinanthropus is the name of the genus of a hominin discovered in the 1920s in northern China, which lived for over 400,000 years in the Zhoukoudian cave, southwest of Beijing. The excavations unearthed 14 skulls constituting what would become the largest collection of fossil hominids ever discovered for this very early period of the human lineage and at a single site. The oldest specimen, Skull III, is dated to the Middle Pleistocene (770 ka). This genus has become obsolete since the attribution of the name Homo to numerous African and Eurasian fossils, but it remains synonymous with the Homo erectus of Northern China, from which a whole line of thought has been built up on the high position of the cerebellar fossa and the less pronounced inclination of the cerebellar face of the petrous pyramids that form the posterior base of the neurocranium. Indeed, the clivus and the foramen magnum are at the crossroads of encephalization and the straightening of the spinal column which characterizes the process of hominization, or the axial straightening. However, as is often the case, the cranial base was incomplete. The skulls disappeared in 1941 during the Second Sino-Japanese War (1937-1945). Interest in axial straightening fell into disuse and was supplanted by an interest in bipedal locomotion, even though its use was not the cause of the process. We therefore propose a method for virtually reconstructing the orientation of the clivus from the CTLe Sinanthrope est le nom d’un genre d’hominien découvert dans les années 1920 en Chine du Nord et ayant vécu pendant plus de 400 000 ans dans la grotte de Zhoukoudian, au sud-ouest de Pékin. Les fouilles ont extrait 14 crânes constituant ce qui allait devenir la plus importante collection d’hominidés fossiles jamais découverts pour cette période très ancienne de la lignée humaine et sur un seul site. Le plus vieux spécimen, le crâne III, est daté du Pléistocène moyen (770 ka). Ce genre est devenu obsolète depuis l’attribution du nom Homo à de nombreux fossiles africains et eurasiens, mais il reste synonyme de l’Homo erectus de la Chine du Nord à partir duquel une réflexion s’est édifiée sur la position haute de la loge cérébelleuse et sur l’inclinaison moins prononcée de la face cérébelleuse des pyramides pétreuses, l’ensemble formant la base postérieure du neurocrâne. En effet, le clivus et le trou occipital placés dans le plan sagittal médian, sont au carrefour de l’encéphalisation et du redressement de la colonne vertébrale qui caractérise le processus d’hominisation, ou le redressement axial. Toutefois la base crânienne était incomplète comme c’est très souvent le cas. Les crânes ont disparu en 1941 lors de la seconde guerre sino-japonaise (1937-1945) et l’intérêt pour le redressement axial est tombé en désuétude supplanté par un intérêt pour la locomotion bipède alors que son usage n’en est pas la cause. Nous proposons donc une méthode pour une reconstitution virtuelle de l’orientation du clivus à partir du CT scan du crâne III, l’unique spécimen dont chacun des os conservés avait été moulés sur ses deux faces. Cette nouvelle méthode peut être appliquée à d’autres CT scan de crânes incomplets permettant ainsi de placer le degré de redressement du squelette axial d’Homo erectus dans la phylogenèse des hominidés
Genetic Algorithm-based Control of a Modular On-Board Charger for Electric Vehicle Applications
No full textInternational audienceThis paper presents the operation and control of a modular on-board charger (OBC) for electric vehicle (EV) applications. The modular design enhances fault tolerance, scalability, and thermal management, making it suitable for high-power EV applications. Singlestage isolated Cuk-based converters are used as submodules, supporting bidirectional power flow for enhanced energy efficiency. Additionally, the modular OBC operates efficiently in various modes, including normal driving, regenerative braking, and grid-connected charging, thanks to its integrated structure. A key innovation is the implementation of genetic algorithm (GA)-based controllers, which optimise control parameters to address the right-half-plane (RHP) zero challenges inherent in Cuk converters, thereby improving system stability and dynamic performance. Simulation and experimental results in charging mode demonstrate robust performance, highlighting precise grid current control, effective power factor correction, and stable battery charging under both normal and partial fault conditions
Steady-State Analysis and Control of Active Current Injection Based Three-Phase PFC Rectifier
No full textInternational audienceThe paper investigates a boost-integrated current injection-based unity-power-factor three-phase ac-dc converter. It presents a steady-state stress analysis and identifies various circuit modes which are required to design the converter. A simple feedforward controller is proposed and simulated