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The battery lifetime of Electric vehicles (EVs) is affected by hot temperatures and high charging and discharging effective battery current. Hybrid energy storage systems (HESS) coupling the best a...

The Acknowledgments section was incorrect in the original article. It should read as follows.

The evolution in battery technology is the key to developing the most efficient Electric Vehicles and winning the challenge for the future E-mobility. As it is difficult to describe battery behavior, we seek in this study to determine an accurate circuit model of the battery that can be used in simulation software. Different tests were performed on Panasonic model NCR18650B lithium batteries in order to find an accurate model that characterizes their behavior in four essential criteria: state of charge, internal resistance, differential capacitance and efficiency. The novelty of this work is the implementation of a technical approach that considers DC and AC model characteristics with their respective experimental approaches, which leads to achieving reliable model performance in both stationary and transient load conditions. The validation of this model using the results from constant current experiments was performed by impedance spectroscopy. It enables the validation of equivalent circuit models for the battery that reproduce faithfully its dynamic response at one particular state of charge.

Combining hybrid Electrical Storage Systems (ESS) is solving many electrical devices problems while using them separately. Batteries present limited charge/ discharge cycles which affect their lifetime and increase their cost. In fact, the lithium ion (li-ion) batteries are more and more studied and evolving in term of cycles. They provide high energy density while the supercapacitors (SCs) ensure long lifetime cycles and operate at large range temperatures. This paper presents a control strategy of battery/ SCs in Uninterruptible Power Supply (UPS) application in order to improve the efficiency, lifetime and reduce the cost. A comparison of using the hybridization with and without control system was established to highlight the power split between the two storage systems. A comparison of lead acid and li-ion battery was established. Finally, different ESS’ financial study was set.

International audience; Energy management of Battery/Supercapacitors (SCs) hybrid energy storage system (HESS) aims to reduce RMS battery current values and enhance the battery lifetime. This paper presents a reinforcement learning (RL) based energy management strategy for Electric Vehicles (EV). This approach allows for learning in real time the optimal power flow distribution between battery and supercapacitors starting from historic of the observation of RMS current of battery. The power management problem is presented with RL formulation verifying the electrical HESS constraints. The presented framework uses the RL technique to control the power flow distribution leading to the minimization of the RMS battery current. Particularly, we propose a methodology that generates optimal frequency sharing policy between battery and SCs taking into account the load variations of the EV dynamically in real time. Numerical simulations carried out on Matlab/Simulink confirmed the convergence of the RMS battery current to the optimal value without any prior knowledge of the driving conditions. The proposed framework aims to adapt automatically the power management policy to the optimal solution.

International audience; Battery/Supercapacitors combination offers superior performances for a hybrid electric energy storage system in Electric Vehicles. This paper, presents a frequency power sharing strategy to get the best use of complementarity between battery and supercapacitors. Storage devices are sized based on reduced scale specifications for the studied EV. Power and current waveform simulation results are shown for each storage device due to the use of a frequency power sharing policy. Various power split configurations are analyzed to study their effect on battery current waveforms. Optimal frequency sharing policy for the battery/SCs hybrid reducing RMS battery current is obtained. The best use of battery/SCs association provides significant improvements of Electric Vehicle performances in terms of battery lifetime and amortized cost.

International audience; The success of hybrid electrical storage systems which combines batteries and supercapacitors is related to the manner how these devices are managed. In this paper, optimal use of the complementarity between batteries and supercapacitors in electric vehicles is studied. First, storage devices are sized based on reduced size specifications of the electric vehicle. Then, power waveforms for each storage device obtained by simulation using the frequency sharing strategy are presented. Different values of filter constant are therefore analyzed to show the variation effect of power sharing strategy on battery current waveforms. The optimal filter constant is finally determined. It offers reduced values of RMS battery current and enhancement of battery service life.

International audience; Hybrid electrical energy storage systems (HESS) show promise for solving the problems and exploiting the benefits of heterogeneous electrical storage systems (ESS). This paper compares the performance of a lead-acid battery/supercapacitors hybrid to that of a battery alone under pulsed loads. Two types of aging protocols, using pulsed and smoothed power, were carried out on VRLA batteries at 40 °C. These protocols typically illustrate a single or hybrid battery’s use for an Uninterruptible Power Supply. In HESS, the supercapacitors smooth the power demand applied to the battery, and, when idle, the battery charges the supercapacitors. The same amount of energy is extracted from the battery during both protocols. The experiment indicated that the battery alone performs 150 ten-minute-cycles before reaching the end of its life. In the hybridized battery, the power dissipated was reduced to 36% of that used by the battery alone, and the number of cycles increased by 70%. The use of a hybrid also reduced the battery’s capacity fade by 60% and its increase of internal resistance by 83%. Finally, the amortized cost of the hybrid system was 17.6% less than that of the battery alone.

Combining Fuel Cell (FC) system with high power density Supercapacitors (SCs) leads to a system with a high efficiency, high performance and long lifetime. This paper compares two configurations for FC/SCs combination in Uninterruptible Power Supply (UPS). The objective is to present the power split between Fuel Cell and Supercapacitors hybrid system by MATLAB/Simulink software. The main criteria studied are system performance, lifetime and UPS cost.

This work contributes to the optimization of a hybrid storage system that combines lithium-ion batteries with supercapacitors used for electric vehicles. This hybridization structure was chosen due to the complementarity between both used storage devices. Our study focuses on the implementation of advanced energy control and management techniques. Using better the storage system represents the goal of this thesis. Our approach is to develop a real time algorithm of energy management taking into account battery electrical and thermal behaviors. A comparative study evaluates the benefits and the drawbacks of each proposed strategy in order to offer various choices between low cost power sharing solutions and control strategy with high performances. An experimental bench was implemented to apply the theoretical concept; Ce travail contribue à l’optimisation d’un système de stockage hybride couplant une batterie lithium-ion et des supercondensateurs pour les véhicules électriques. La complémentarité entre ces deux sources d’énergie permet l’amélioration des performances globales du système. Notre étude porte sur la mise en oeuvre de techniques avancées de contrôle et de gestion de l’énergie. Notre objectif est d’avoir une meilleure utilisation du système de stockage. Dans ce cadre, notre démarche est de développer une gestion d’énergie en temps réel qui tient compte des contraintes électriques et thermiques des systèmes de stockage. Une étude comparative sur les avantages et les inconvénients de différentes techniques de gestion d’énergie nous a permis d’effectuer le choix entre un partage de puissance à moindre coût et un partage performant de l’énergie entre les systèmes de stockage. Un banc expérimental a été mis en oeuvre afin de concrétiser la démarche théorique

This work contributes to the optimization of a hybrid storage system that combines lithium-ion batteries with supercapacitors used for electric vehicles. This hybridization structure was chosen due to the complementarity between both used storage devices. Our study focuses on the implementation of advanced energy control and management techniques. Using better the storage system represents the goal of this thesis. Our approach is to develop a real time algorithm of energy management taking into account battery electrical and thermal behaviors. A comparative study evaluates the benefits and the drawbacks of each proposed strategy in order to offer various choices between low cost power sharing solutions and control strategy with high performances. An experimental bench was implemented to apply the theoretical concept; Ce travail contribue à l’optimisation d’un système de stockage hybride couplant une batterie lithium-ion et des supercondensateurs pour les véhicules électriques. La complémentarité entre ces deux sources d’énergie permet l’amélioration des performances globales du système. Notre étude porte sur la mise en oeuvre de techniques avancées de contrôle et de gestion de l’énergie. Notre objectif est d’avoir une meilleure utilisation du système de stockage. Dans ce cadre, notre démarche est de développer une gestion d’énergie en temps réel qui tient compte des contraintes électriques et thermiques des systèmes de stockage. Une étude comparative sur les avantages et les inconvénients de différentes techniques de gestion d’énergie nous a permis d’effectuer le choix entre un partage de puissance à moindre coût et un partage performant de l’énergie entre les systèmes de stockage. Un banc expérimental a été mis en oeuvre afin de concrétiser la démarche théorique