Fiche individuelle

The energy sources in a Hybrid Energy Storage System are coupled by a DC–DC converter. Nevertheless, this device’s mass is irrelevant when evaluating the performance of such a system in terms of density, so it must be reduced to achieve maximum performance. This can be achieved with the solution presented in this paper: a coupling architecture based on a controlled current source, in which the DC–DC converter’s processed power depends on the voltage difference between the two sources. If this difference is zero, so is the power processed by the converter. Minimizing this power leads to a reduction of the converter’s mass and volume, increasing system performance. In this paper, the controlled current source cascade architecture combines two lithium-ion batteries to supply a limited-range electric vehicle. Its operation is addressed and validated by simulation and experimental results. For the experimental validation, the batteries and the load were emulated by power supplies, with a 2 kg, 3.3 kW evaluation board serving as DC–DC converter. The findings reveal that the examined architecture enables a substantial reduction in the converter’s sizing power, up to a factor of 14 compared to a conventional solution commonly seen in the literature.

With the integration of power electronic converters and components, an accurate thermal design becomes essential. Hence, precise thermal models for components are needed for their optimal design. This paper focuses on the development of an analytical model for the design of thermal resistance of planar magnetic cores (PMC). Based on computational fluid dynamic (CFD) simulations, the PMC design thermal resistance variation is studied, according to ambient temperature and level of losses. Then, a polynomial equation is developed to model those variations, and coefficients are deduced for all the sizes of PMC. This analytical model, useful for designers, is finally validated with thermal measurements on a planar transformer prototype.

A Hybrid Energy Storage System (HESS) uses DC-DC converters to couple its energy sources. However, this device represents a "dead weight" in the system and must be reduced to a minimum in order to maximize the HESS' performance. This work proposes a new coupling architecture to reduce the converter's volume and mass. Not yet addressed in the literature, this architecture is based on a series coupling of the sources. In this case, a DC-DC converter is used to control the current difference between the two sources. If this difference is zero, so is the power processed by the converter. By reducing the power processed by the converter, its mass and volume can be reduced. Simulation and experimental tests were carried out to validate the architecture concept. For the latter, power supplies were used to emulate the batteries and the load, and a 2 kg, 3.3 kW evaluation board served as the DC-DC converter. The results show that, compared to a conventional solution that is usually adopted in the literature, with the series architecture, it is possible to reduce the converter sizing power by almost 3.7.

Conceiving planar magnetic components for power electronic converters is very constraining, especially in the case of prototype development. Indeed, such making requires skills, specific appliances as well as human time for setting up the machine tools and the fabrication process. With the emergence of Fabrication Laboratory (FabLab), conceiving of planar copper foil prototypes becomes more feasible in a shortened time process for engineers and researchers. This paper presents a methodology and process for conceiving power planar transformers with the help of machines and tools that can be found in the usual FabLab.

One of the main technological stumbling blocks in the field of environmentally friendly vehicles is related to the energy storage system. It is in this regard that car manufacturers are mobilizing to improve battery technologies and to accurately predict their behavior. The work proposed in this paper deals with the advanced electro-thermal modeling of a hybrid energy storage system integrating Lithium-ion batteries and supercapacitors. The objective is to allow the aging aspects of the components of this system to be taken into account. The development of a model including the electro-thermal behaviors makes it possible to evaluate the progressive degradation of the performance of the hybrid energy storage system. The characterization of both components constituting the hybrid system is carried out via a hybrid Particle Swarm–Nelder–Mead (PSO–NM) optimization algorithm using the experimental data of an urban electric vehicle. The obtained results show the good performance of the developed model and confirm the feasibility of our approach. The use of the PSO–NM optimization algorithm facilitated the identification of the parameters of the developed model with high efficiency, as the error observed is less than 3%. The advanced model associated with an adapted sizing method can be used in many cases to compare energy management strategies in electric vehicle applications.

This paper presents the modelling of the DC-DC Multilevel Modular Converter (DC-DC MMC) with half-bridge Sub-Modules (SM) and the control based on the inversion of its model. The DC-DC MMC structure presents many advantages such as its modularity, the absence of capacitors on the high DC bus voltage and a very low switching frequency due to the large number of SMs. This topology also preserves the intrinsic disadvantages of the MMC as the complexity of modelling and controlling due to the large number of semiconductors and state variables to control. The control of this converter cannot be symmetrical due to the interconnection of the two parts by an internal AC grid. The control strategy of one part of the DC-DC MMC uses the conventional control scheme with currents controls and stored energy control. The second one uses the energy control and produces the waveform of the three-phase internal AC bus voltage linking the two parts of the converter. The explicit control for the generation of internal AC voltages guarantees the correct operation of the converter even in a critical DC voltage dip on one or the other DC buses. Thus, it avoids the need of a DC circuit breaker or the use of full bridge MMC sub-modules. The validity of the proposed control is verified by simulation using Matlab-Simulink.

The M2DC exploits the interleaving between the three legs of an MMC to realize a promising uninsulated DC/DC converter to interconnect HVDC grids. This paper details a current and energies decoupled model of the M2DC. The major idea proposed in this paper is focused on the full energy control generating optimal current references to minimize the internal currents magnitude. The energy sum and difference models are fully detailled. Both current and energy control loops are based on the model inversion principle in order to control all the state variables. The proposed control is based a dynamic control developed with the model inversion principle associated on an optimization of the current magnitude deduced from a quasi static analysis. All dynamics of the system are then explicitly controlled, which guarantee a good dynamic behavior during the transient. Therefore, current and energy controls are presented in details. Simulation results show the dynamic behavior of the converter for various operating points.

Thermal performance of power converters is a key issue for the power integration. Temperatures inside active and passive devices can be determined using thermal models. Modelling the temperature distribution of high frequency magnetic components is quite complex due to diversity of their geometries and used materials. This paper presents a thermal modelling method based on lumped elements thermal network model, applied to planar magnetic components made of EE and E/PLT cores. The 3D model is automatically generated from the component’s geometry. The computation enables to obtain 3D temperature distribution inside windings and core of planar transformers or inductors, in steady state or in transient case. The paper details the proposed modelling method as well as the automated tool including the problem definition and the solving process. The obtained temperature distributions are compared with Finite Element simulation results and measurements on different planar transformers.

In this paper, a dynamic model of Li-ion batteries incorporating electrothermal and ageing aspects is proposed for electric vehicle applications. The main goal of the proposed model is to be both simple and sufficiently representative of the physical phenomena occurring in a battery cell. These two features allow for using this model as an evaluation tool of electric vehicle performances under different operational and environmental conditions. The developed model is based on an equivalent circuit diagram coupled with a thermal circuit and a semi-empirical ageing equation. Identification of parameters in the dynamic model is conducted by measurement tests in time-domain, which uses a hybrid Particle Swarm–Nelder–Mead optimization algorithm to achieve excellent prediction over the whole applicable current and state of charge ranges. The validation results show that the proposed model is able to simulate the dynamic interaction between the battery ageing and the thermal as well as electric behavior with sufficient accuracy in the range tested.

The More Electric Aircraft (MEA) has motivated aircraft manufacturers since few decades. Indeed, their investigations lead to the increase of electric power in airplanes. The challenge is to decrease the weight of embedded systems and therefore the fuel consumption. This is possible thanks to new efficient power electronic converters made of new components. As magnetic components represent a great proportion of their weight, planar components are an interesting solution to increase the power density of some switching mode power supplies. This paper presents the benefits and drawbacks of high frequency planar transformers in DC/DC converter, different models developed for their design and different issues in MEA context related to planar’s specific geometry and technology.

Loss values are key parameters for designing high performance high frequency (HF) magnetic components for power electronics (PE) converters. With the increase of PE switching frequencies, copper losses have to be precisely quantified, ideally until some megahertz. In the literature, many 2-D numerical simulations based on finite element analysis (FEA) are performed for such computations. 3-D FEA studies of planar components are still limited because of modeling problems, computational resources and computing time. In this paper, quantitative comparisons between 2-D and 3-D simulation results for planar inductors are achieved focusing on copper loss computation. Results are compared in terms of simulation performances and accuracy. The aim of the paper is to highlight benefits of 2-D and 3-D FEA simulations in order to choose the appropriate model according to the studied problem.

Modeling dynamic behaviors of the Li-ion battery and supercapacitor in electric vehicle applications is a key aspect for the emulation of the hybrid power supply. In this paper, a dynamical model based on two nonlinear equivalent circuits is developed to describe the characteristics of the battery and supercapacitor during both steady-state and transient conditions. The necessary parameters for proposed model are extracted from measurement data in time and frequency-domain using an optimization algorithm. The developed model is coupled to power electronics devices fed by DC power supply to carry out a laboratory emulator of the hybrid power supply. This tool is mainly used for testing and verification of the electric vehicle performances with convenient and reproducible way. The proposed emulator avoids time-consuming preconditioning and safety problems generally caused by the misuse of electrochemical components such as the Li-ion battery. The modeling and experimental results show a good performance of the hybrid power supply emulator and confirm their feasibility over a wide range of operating points.

Combining a high power source like a supercapacitor with a Li-ion battery for electric vehicle applications results in good performance improvements, highly efficient, long lifetime, lightweight design and relatively modest cost of the overall source. A hybrid energy storage system controlled by a smart energy management strategy can play a key role in the design and development of multi-source electric vehicles. In this work, an optimal energy management strategy based on particle swarm optimization incorporating Nelder-Mead simplex method is proposed. The goal of the proposed strategy is to minimize the battery power stress and improves its lifetime. This is achieved by coupling a rule-based method based on the knowledge of the battery and supercapacitor efficiency operating with a hybrid Particle Swarm–Nelder–Mead (PSO–NM) optimization algorithm. This latter approach is proposed to optimize the control parameters of the rule-based energy management strategy, once the off-line optimization algorithm is over, the control method can be implemented on-line. The obtained results demonstrate significant lifetime enhancements for Li-Ion battery, an increase of up to 20% as compared to the mono-source based on regular single battery.

Currently, the vehicle manufacturers use the high power Li-ion technology to supply the electric and hybrid vehicles. This technology is able to ensure the power needed to propel the vehicle. Until now several studies have been made by the laboratories and manufacturers to characterize this technology. The aim of these test (electric, thermal, aging,…) is to make comparison between Li-ion technologies and choice the best one for each application. For that, they use accelerated cycling with different condition to characterize cells, what can reduce the tests duration. Unfortunately, this type of cycle can’t give us information about the aging of HP Li-ion technology under real use of the vehicle. Firstly, the requirements specification (vehicle specification, battery technologies, mission) has been presented. After that, we will present the test bench developed in our laboratory to characterize batteries and study the aging of the HP technology. In this paper we present the study of the Li-ion HP behavior during almost 3 years and the modelling (electric, thermal and aging modelling) using a real driving cycle. The experimental results are compared to the results obtained with the developed ageing model. The obtained results prove the good performances of this technology in electric vehicle applications.

This paper examines and optimizes parameters that affect the sizing and control of a hybrid embedded power supply composed of Li-ion batteries and supercapacitors in electric vehicle applications. High demands including power and energy density, low charge/discharge power stress on the battery (long lifetime), lightweight design and relatively modest cost at the same time cannot be provided solely by batteries or supercapacitors. For this reason, we propose the use of a Li-ion battery/supercapacitor hybrid embedded power supply for an urban electric vehicle. The sizing process of this system including the optimization of the power sharing is done thanks to a developed hybrid Particle Swarm–Nelder–Mead (PSO–NM) algorithm involving multi-objective optimization. This approach also allows us to optimize the proposed energy management strategies based on frequency rule-based control and different ways of supercapacitors energy regulation. Obtained results show that the hybrid embedded power supply with the proposed control strategies is able to offer the best performances for the chosen electric vehicle in terms of weight, initial cost and battery lifetime.

Predetermination of losses and inductance values in the design phase, is necessary for the development of high-performance magnetic components for power electronics. Numerical modeling, based on the Finite Element Method (FEM) can be used to determine the characteristics of a particular component with a complex geometry in high frequency (HF). These models are very accurate but the computation time required is high compared to analytical models. The Model Order Reduction (MOR) methods can be applied to reduce the computation time while maintaining high accuracy. Nowadays, the Proper Orthogonal Decomposition (POD) is the most popular of MOR approaches. This technique has been applied to study problems in many elds of engineering. In this paper, the POD method is developed to solve magneto-harmonic problems in order to study a planar magnetic inductor.

In recent years, Li-ion batteries are widely used in various applications, such as electric and hybrid vehicles application. Their higher specific power and energy density, high cycle lifetime and decreasing costs have made them an attractive and alternative energy storage technology to lead-acid or nickel- metal hydride batteries in embedded power supplies. In the present work, the electric modeling of a Li-ion battery cell in real operating conditions imposed by an electric vehicle application is carried out. A dynamic equivalent circuit model has been used to simulate several electrochemical processes occurring in a commercially available 40 Ah Li-ion battery cell with NMC cathode material and graphitic anode. The model is parameterized with measurement data in time-domain using a hybrid Particle Swarm–Nelder–Mead (PSO–NM) optimization algorithm. This last one is used to solve the parameters identification problem of Li-ion battery model. The developed model of Li-ion battery cell has been validated on real driving cycle provided by an urban electric vehicle. Obtained results show that there is a good match between experiment and simulation results with a maximum modeling error less than 0.5%, which proves the well performance of our model and confirm the interest of a hybrid (PSO–NM) optimization algorithm for battery identification parameters.

Today, industry has not fully embraced the matrix converter solution. One important reason is its high control complexity. It is therefore relevant to propose a simpler but efficient modulation scheme, similar as three phase VSI modulators with the well-known symmetrical carrier-based ones. The modulation presented in this paper is equivalent to a particular Space Vector Modulation (SVM) and takes into account harmonics and unbalanced input voltages, with the same maximum voltage transfer ratio (86%). The aim of this work is to propose a simple and general pulse-width-modulation method using carrier-based modulator for an easier matrix converter control. Furthermore, a simple duty cycle calculation method is used, based on a virtual matrix converter. Finally, simulations and experimentations are presented to validate this simple, original and efficient modulation concept equivalent to matrix converter SVM.

Modern controlled electric drive applications, such as lifts, port rubber tyred gantry cranes, and tooling machines, are characterized by high ratio of the peak to average power. Moreover, such applications have a need for braking at rated power. In ordinary drives, the braking energy, which represents 30%–40% of the consumed energy, is dissipated on a brake resistor. Apart from this “energetic” issue, the mains interruption, the input current quality, and the mains peak power are additional issues to be addressed. A novel ultracapacitor-based controlled regenerative electric drive with peak power-smoothing function is presented in this paper. The ultracapacitor with an interconnection dc–dc converter is used to store and recover the braking energy. In addition, the dc–dc converter controls and smooths the rectifier input power. In comparison to state-of-the-art solutions, the new solution has better performance regarding size, cost, and efficiency. The presented solution is theoretically analyzed and experimentally verified. The results are presented and discussed.

In this paper, a study of the supercapacitors’ ageing process is presented. The originality of this work is that the tests are made under conditions similar to those of an industrial application. A continuous cycling is applied in order to obtain these test conditions. The measurement is done thanks to a test bench developed in our laboratory. More than 560,000 cycles have already been done, which corresponds to 325 cumulated days of continuous cycling. These tests allow to understand the ageing process of supercapacitors and to follow the evolution of theirs characteristics during their lifetime. The aim of this work is to study the behavior of the cells which compose the supercapacitors module (48V/ 112F).

Most of modern controlled electric drive applications, such as lifts, cranes, and tooling machines, are characterized by a high ratio of the peak to average power. In addition, such applications have high demand for braking at the full rated power. In ordinary drives, the braking energy, which represents 30%–50% of the consumed energy, is dissipated on a brake resistor. Apart from this “energetic” issue, power supply interruption and the input current quality are two additional issues to be solved. A novel regenerative controlled electric drive based on an ultracapacitor as energy storage is presented in this paper. The ultracapacitor with an interface dc–dc converter is used to store and recover the braking energy. In addition, the dc–dc converter controls the rectifier current and reduces the drive input current total-harmonic- distortion factor down to 30%. Moreover, the dc bus voltage is boosted and controlled to be constant and ripple free regardless of the load and the mains voltage variation. In comparison to state-of-the-art solutions, the new solution has better performance regarding size, cost, and efficiency. The presented solution is theoretically analyzed and experimentally verified. The results are presented and discussed.

Two issues are still a great challenge in design and application of advanced controlled electric drives, namely recovery of the braking energy and ride-through capability of the drive system. Apart from the ordinary solutions, such as back to back and matrix converters, an approach based on the ordinary diode front-end drive converter equipped with an energy storage element is used in some applications, such as traction and lift drives. This approach becomes in the focus recently with rapid development of electrochemical double layer capacitors (EDLC), so-called ultra-capacitors. To achieve the system flexibility and better efficiency, the ultra-capacitor is connected to the drive via a dc-dc converter. The converter is controlled in such a way to fulfil the control objective; control of the dc bus voltage, the ultra-capacitor state of the charge and peak power filtering. In this paper, we have presented modelling and control aspects of the regenerative controlled electric drive using the ultracapacitor as energy storage and emergency power supply device. The presented model and control scheme have been verified by Matlab/Simulink simulation. The presented concept was experimentally verified on a 5.5kW prototype. The results are presented and discussed in this paper.

A novel three-phase diode boost rectifier is proposed in this paper. The core of the proposed topology is a power conversion device (the loss-free transformer (LFT)) with two terminals; an input and one output. The input is parallel-connected with the dc bus capacitor, while the output is connected between the rectifier plus rail and the dc bus plus rail. The LFT is controlled in such a way to control the rectifier current and boost the dc bus voltage. In contrast to the ordinary boost rectifiers, the switches of new boost rectifier are rated on a fraction of the dc bus voltage and a fraction of the input current. It makes this topology very compact and efficient. Power rating, size and losses depend strongly on ratio between the dc bus voltage and rectifier voltage (boosting factor). For example, if the boosting factor is low, below 1.5, the power converter efficiency could be 98 to 99%. The proposed boost rectifier has been analyzed and experimentally verified on 5.5kW prototype. The results are presented and discussed.

Two issues are still a great challenge in design and application of advanced controlled electric drives: 1) recovery of the braking energy, and 2) ride-through capability of the drive system. Apart from ordinary solutions, such as back to back and matrix converters, the ordinary drive converter equipped with an energy storage element is used in specific applications such as traction and lift drives. This approach became in the focus recently with rapid development of electrochemical double layer capacitors (EDLC), so-called ultra-capacitors. The ultracapacitor is an electro-chemical capacitor having energy density much greater than that of standard electrolytic capacitors. Additionally, the ultra-capacitor power density is much higher than that of the existing electro-chemical batteries. In this paper, a regenerative controlled electric drive having extended ridethrough capability is discussed. Basic principle has been extensively analysed, including detailed analysis of all operational modes. A bi-directional three-level dc-dc converter has been considered as the interface power converter. The ultracapacitor design guide line is given. A control algorithm that allows control of the dc bus voltage and the ultra-capacitor voltage and current has been presented and briefly analysed. Regenerative controlled drive system has been tested and the results presented and discussed.

Electrochemical double-layer capacitors, which are well known as ultracapacitors, have intensively been used in power conversion applications such as controlled electric drives, active filters, power conditioners, and uninterruptible power supplies. The ultracapacitor is employed as the energy storage device that can be fully charged/discharged within a few seconds. To achieve better flexibility and efficiency, the ultracapacitor is connected to the power conversion system via an interfacing dc–dc power converter. Various topologies are used as the dc–dc power converter: nonisolated two-level single-phase or multiphase interleaved converters and many varieties of isolated soft-switched dc–dc converters. A three-level nonisolated dc–dc converter as a candidate for ultracapacitor applications is proposed and analyzed in this paper. The topology is theoretically analyzed, and design guidelines are given. The modeling and control aspects are discussed. A 5.5-kW prototype was designed, and the proposed topology was experimentally verified on a general-purpose controlled electric drive. Experimental results are presented and discussed.

Efficiency of high-power uninterruptible power supplies (UPSs) is a fundamental criterion regarding the permanent use of such a device. A state of the art on soft switching over constraint of UPS application has been made. The principle of auxiliary resonant commutated pole using autotransformer has been identified as the most interesting way to increase efficiency or switching frequency. Its application for multilevel converters has been studied. A simplified resonant pole has been proposed for a three-level rectifier used as power factor corrector. The design criteria have been discussed. A single phase of a 200-kVA three-level rectifier has been realized and qualified in switching mode. To assess the gain of this principle, the switching losses have been measured on the prototype in both hard and soft switching. The switching losses have been divided by two.

Turn-on performance of a reverse blocking insulated gate bipolar transistor (RB-IGBT) is discussed in this paper. The RB-IGBT is a specially designed insulated gate bipolar transistor (IGBT) having ability to sustain blocking voltage of the both polarities. Such a switch shows superior conduction but much worst switching (turn on) performances compared to a combination of an ordinary IGBT and blocking diode. Because of that, optimization of the switching performance is a key issue that makes the RB-IGB not well accepted in the real applications. In this paper the RB-IGBT turn-on losses and reverse recovery current are analysed for different gate driver techniques and a new gate driver is proposed. Commonly used conventional gate drivers do not have capability for the switching dynamics optimization. In contrast to this, the new proposed gate driver provides robust and simple way to control and optimize the reverse recovery current and turn-on losses. The collector current slope and reverse recovery current are controlled by the means of the gate emitter voltage control in feed-forward manner. In addition, the collector emitter voltage slope is controlled during the voltage falling phase by the means of inherent increase of the gate current. Therefore, the collector emitter voltage tail and the total turn on losses are reduced, independently on the reverse recovery current. The proposed gate driver was experimentally verified and the results presented and discussed.

In adjustable speed drive applications, the switching of the inverter semiconductors generates common mode currents as well as harmful overvoltages on the motor terminals when long cables are used. Consequently, bulky and expensive input and output filters must be used. This work aims at reducing these disturbances from their origin by using a three-level neutral-point-clamped (NPC) inverter controlled with a new pulse-width-modulation (PWM) strategy. Whereas previous common mode noise-reducing strategies usually generate higher overvoltages than conventional ones, the proposed PWM is able to manage both problems thanks to its internal degrees of freedom.

Pulse-width-modulated (PWM) voltage-source inverters are known to provoke high-frequency disturbances in motor-drive applications, especially when long cables are used. Indeed, the parasitic elements of the cable along with steep voltage transitions due to semiconductor switchings are responsible for conducted electromagnetic emissions as well as high overvoltages on the motor terminals. Therefore, several specific PWM schemes have been proposed in order to reduce these phenomena without requiring large passive filters. However, strategies which reduce common-mode currents (mainly conducted electromagnetic emission) tend to increase the overvoltages generated on the motor. This paper focuses on a new PWM strategy which reduces the common-mode currents generated by three-level inverters. It provides a control algorithm which makes sure that the motor overvoltages never exceed those of conventional strategies, while improving the electromagnetic-compatibility performance of the drive.

This paper deals with conducted ElectroMagnetic Interferences in adjustable speed drive (ASD) systems. For some years, the use of high speed switching power devices in ASDs induces high voltage (dv/dt) and high current (di/dt) variations that excite the parasitic elements of the power circuit, inducing conducted emissions. The advent of these devices has thus generated several unexpected problems, such as premature deterioration of motor ball bearings and high increases in the EMI levels, caused by the circulation of the high frequency currents. In order to evaluate the level of the common mode and the differential mode currents in the ASD system, it is necessary to use a precise model of the PWM inverter, power cable and AC motor that takes into account various phenomena, which appear when the frequency increases. First a PWM inverter and shielded 4-wire power cable model are presented. Then, a new high frequency modeling method of the AC motor is proposed. Finally, the ASD system is simulated and the obtained results are compared to the experimental measurements in the frequency and time domains.

A storage supercapacitor subsystem is studied for insertion in a series hybrid electric vehicle. This subsystem is composed of a supercapacitor bank and a braking resistor used when the supercapacitor voltage is at its maximum value. Generally, when the maximum voltage is reached by supercapacitor, a voltage drop occurs because of the current cancellation in the series resistance of the supercapacitor. Thus the stored energy is reduced compared to the maximum value that could be reached. To overcome this drawback, new control strategies are proposed by acting on the braking resistor. Energetic Macroscopic Representation (EMR) is used to organize the numerous blocks required for modelling and control. Experiment results are provided and highlight the increase of energy storage.

RÉSUMÉ. Cet article présente une nouvelle stratégie de modulation de largeur d’implusion destinée à réduire les courants de mode commun dans les applications de variation de vitesse utilisant un onduleur à trois niveaux de type neutral-point-clamped. Il détaille l’implantation de cette commande par un modulateur à porteuses en dents de scie permettant de contrôler les degrés de liberté apportés par la stratégie. ABSTRACT. This paper presents a new pulse-width-modulation strategy for the reduction of common-mode currents in adustable-speed-drive applications using a three-level neutral-pointclamped inverter. It is implemented through a saw-tooth carrier-based modulator which makes it possible to control the degrees of freedom provided by the strategy.

Depuis quelques années le marché des supercondensateurs de forte puissance est en pleine émergence. Ces composants permettent de stocker une énergie conséquente et surtout de l’emmagasiner et de la restituer très rapidement (les courants de charge et décharge peuvent atteindre 500 A). Mais le faible niveau de tension que supportent ces éléments (2 à 3 V) impose de les associer en série, entraînant divers problèmes de fiabilité et de durée de vie. Dans cet article, une étude de caractérisation d’un module supercondensateur 100 F/56 V constitué de 28 éléments 2700 F/2,3 V est proposée. Cette étude permet de mettre en évidence les phénomènes de dispersion de tension des supercondensateurs. Ce travail de caractérisation a pour objectif d’une part de procéder au cyclage de ces modules dans le but de connaître l’évolution de leurs performances tout au long de leur vie, et d’autre part d’acquérir un savoirfaire dans ce domaine afin de mieux connaître ces composants en termes de performances et également en termes de contraintes technologiques.

Adjustable-speed drives involve common-mode voltages, which generate common-mode currents flowing to the ground through stray capacitances of electric machines. These currents are known to provoke premature motor-bearing failures, as well as electromagnetic interferences disturbing neighbor electronic devices. Furthermore, high-voltage applications involve high levels of these conducted emissions, which must be lowered by using bulky and expensive filters. This paper aims at elaborating a new pulsewidth-modulation (PWM) strategy in order to reduce the common-mode currents generated by threelevel neutral-point-clamped inverters. The proposed strategy also provides the ability to balance the neutral point of the dc-bus capacitors. Experimental results both in time and frequency domains confirm that the new PWM improves the electromagneticcompatibility behavior of the drive compared with conventional strategies.

The Modular Multi-Level DC-DC Converter (M2DC) is an attractive non-isolated DC-DC converter topology for HVDC grid. In order to carry out MTDC grid stability studies, the development of reduce order models of converters is necessary. This article first presents the M2DC converter. Then, the reduce order model will be developed in the second part. The development of the control of this model will be carried out in the third part. Atlast, the comparison of the reduce order model and its control with the average arm model will be performed in the later section of the paper.

The Modular Multilevel DC Converter is an attractive non-isolated topology to interconnect High Voltage DC Links. This paper presents the interaction among control, component design and efficiency of this converter. The impact of the two degrees of freedom on the design and the efficiency is analyzed.

Recent studies have shown that the use of battery-battery coupling in Hybrid Energy Storage Systems (HESS) presents advantages in terms of mass, volume and cost when compared to the battery-supercapacitor coupling. However, the sizing of this type of system is not much studied in the literature. So, in this paper a graphical sizing method using Ragone plots is presented. With this method, a HESS perfectly suited to a given application can be obtained.

When analyzing the characteristics of a Hybrid Energy Storage System in a Ragone plot, it can be seen that the mass of the necessary power electronics has a great influence on the system’s performance. Although many coupling architectures have been studied so far, the size of the power converter is not usually a priority. So, in this paper, a low-volume and high-efficiency converter is proposed. Placed in series between the sources, the converter depends only on the voltage difference between them. In this way, the converter can be reduced, since it does not manage the total power supplied by the accumulators, as a classic converter.

The MMC is the solution today to connect HVDC grids to the current HVAC grid. This paper proposes to evaluate the impact of Zero Sequence Voltage Injection variants, which until now, have not been extensively studied. Such techniques can involve, for example, a reduction of the SM capacitor value, the number of SM requirement and converter losses. The paper presents MMC current model, control and highlights the implication of the zero-sequence voltage. Grid current control structure with the introduction of the zero-sequence voltage is presented in different techniques. These modulation schemes are compared through two main quantities in MMC, the energy requirement defining the SM capacitance value and the power losses.

This paper presents a methodology to evaluate and analyze the volumetric power density of planar magnetics used in power electronics converters. The power density is computed for various EE and E/PLT cores considering optimal configurations for the planar transformers’ design and for its cooling heatsink. The analysis is performed for three cooling configurations: natural convection without heatsink, single sided cooled component with one heatsink, and double sided cooled with two heatsinks. This study can be very useful for designers to evaluate their design specifications and to adapt their technological choices to achieve the desired planar magnetics’ characteristics.

The use of DC transmission is particularly advantageous for long-distance transmission and interconnection of asynchronous AC networks. Several converter topologies can be used for HVDC. Multilevel Modular Converters (MMCs) are the most favored given their technological advantages over other converters topologies. Due to their industrial maturity, they have become essential for all AC / DC conversion. So far, they have always been studied with a voltage source on DC side. However, when the converter is equipped with DC breaker, a series inductor is associated to limit current variations. This has consequences in terms of modeling and control determination. This article aims to propose a modification of the control law in order to take into account this inductor. To facilitate the control organization, the Energetic Macroscopic Representation (EMR) is used.

DC/DC converters are necessary in HVDC networks to adapt different voltage levels, different configurations or to participate in power flow control. This paper focuses on a recent DC/DC converter topology, called Modular Multilevel DC Converter (M2DC), which uses direct DC/DC connection without galvanic separations. A general analysis of the topology is firstly discussed. Afterwards a decoupled mathematical model, reducing the control complexity is proposed. To improve converter’s performances and limit AC constraints on each leg, parameters adjust and inductor sizing are explored. Finally, simulation results are presented to validate the proposed decoupled model and the control. The impact of optimized parameters are shown on AC components values.

In this paper, the thermal resistance of planar magnetic components in natural convection is studied in order to obtain analytical formula taking into account effects of ambient temperature as well as power dissipated inside the component. The analytical model is deduced from Computational Fluid Dynamic simulations and is validated with measurements on prototypes.

Planar technology is an interesting solution for high frequency (HF) magnetic components in power electronic converters. Over the past few decades, the trend is increasingly towards these integrated magnetic components with high power density, especially for embedded systems, automotive and avionics devices. In order to design optimized planar inductances or transformers any aspect of the component’s geometry is important. This paper is focused on one of these aspects: the track shape of copper conductors made of Printed Circuit Board (PCB). Three designs of conventional tracks are simulated by 3D Finite Element Analysis (FEA) to calculate the dynamic (AC) resistances and their resistive factor. Different combinations of these elementary tracks are tested and the influence of the turn shape is highlighted.

This paper presents an innovative Low Losses Modulation of the Matrix Converter. Its principle is to minimize the cumulated switched voltage in each cell by increasing and decreasing progressively the output potential of each matrix cell. This modulation can be applied to all conversion matrices previously proposed for the matrix converter modulation and can be easily implemented with a triangular carrier based modulator adapted for matrix converter cells. The proposed modulation involves the use of all vectors present in the matrix converter space vector approach, including the 6 rotating vectors. Simulations verify the losses decreasing, but also reveal a significant reduction of the output voltages THD, and a very slightly increasing of the input currents THD.

This article presents a new Linear Voltage Stabilization System (LVSS) specially meant for µ-hybrid vehicles using the Stop-Start function. The LVSS stabilizes the battery voltage mainly during the start-up of the ICE limiting the load current using parallels MOSFETs working in linear mode [1]. The Energetic Macroscopic Representation (EMR) is used to model the system and to design its control system. The main advantages of the LVSS are the low price, small volume and the fact of avoiding EMC perturbation. The concept is validated testing the prototype in a real car.

This article presents a new Linear Voltage Stabilization System (LVSS) specially meant for µ-hybrid vehicles using the “Stop & Start” function. The LVSS stabilize the battery voltage mainly during the start-up of the Internal Combustion Engine (ICE) limiting the load current using parallels MOSFETs working in linear mode [1]. The mains advantages are its small volume, avoid of EMC perturbations and specially its low price allowing Stop & Start vehicles to be more accessible to the market. The concept is validated testing the prototype in a real car.

This article presents a Linear Current Limiter (LCL) specially meant for ì hybrid vehicles using the Stop-Start function. The LCL limits the current mainly during the start-up of the Internal Combustion Engine (ICE) in order to maintain the battery voltage stable. Its main advantages is the low price and the fact of avoiding EMC perturbation since it is composed of MOSFETs working in linear mode [1]. The concept is validated limiting the charging current of a capacitor by simulation and comparing with experimental results.

Predetermination of inductances and losses are needed to effectively design magnetic components used in power electronic converters. Their behaviours change with frequency and have to be determined accurately over a wide frequency range, commonly up to 30MHz to account for EMI aspects. In many papers, 2D finite element simulations are widely performed for the calculations of inductances and losses of planar components. These 2D numerical models are generally taken as references to develop analytical models, including the specific case of High Frequency copper losses. 3D studies of such planar components are still limited because they leads to problems related to modeling, computing resources and computing time. In this paper comparisons in terms of performance and precision for 2D and 3D models of planar inductors is presented. The obtained results are compared with impedance measurements on prototypes.

The association of more than one storage system to ensure the supplying of the hybrid and electric vehicle became more and more useful by the cars manufacturers. The asked question in this case is the optimal amount of the deferent energy sources to ensure the mission with the best lifetime. The first parameter witch influence the architecture of the hybrid storage system is the required autonomy. This paper deals with the choice of the architecture and the sizing of the hybrid source composed with battery and supercapacitor packs according to the desired autonomy. In this case, two technologies of Li-ion battery (power and energetic technologies) are associated with the supercapacitor. The obtained result about the size and the ageing of the source will be compared to that obtained using only power technology of Li-ion battery to supply the vehicle.

For hybrid and electric vehicle, high powers are needed for the acceleration, startup and recovery phases. For that, the chosen storage system must insure these high powers. The supercapacitors are powerful storage systems, which can reach more than 4,3kW/kg of specific power, and very high lifetime compared to the other storage components. Until 1957 five generations of supercapacitors are developed by the researcher in the entire world. The deference between these generations depends to the materials used for the electrode and/or the type of electrolyte solution. The use of deferent materials influences directly the behavior of the technology in term of specific power, specific energy, maximum voltage, maximum current and the lifetime. Currently, the manufacturer uses in 90% of the cases the technology with carbon electrodes and acetonitrile like electrolyte. This technology has a high specific energy and good lifetime. On the other hand, this technology is toxic and cheaper compared to the other ones. The aqueous technology can give us the solution for this problem, because of the no-toxicity of the electrolyte and the very high power of this component. Unfortunately, this technology has low specific energy because of the voltage limitation (maximum 1V). This paper deals with the comparison between the two technologies of supercapacitors (carbon electrode + organic electrolyte and carbon electrode + aqueous electrolyte). The characterization and the variation of the ageing of the two technologies according to the number of cycles will be presented.

Three-phase variable speed drives supplied from single-phase mains are briefly analyzed and a novel diode boost rectifier is proposed in this paper. The core of the proposed topology is a multi-switch dc-dc converter with two terminals; an input and one output. The input is parallel-connected with the dc bus capacitor, while the output is connected between the rectifier plus rail and the dc bus plus rail. The converter controls the rectifier current and the dc bus voltage. The rectifier current is controlled constant or pseudo-constant in order to reduce the input current total harmonic distortion (THD). The dc bus voltage is boosted above the mains peak voltage. In contrast to the ordinary single-switch boost rectifiers, the switches of the new boost rectifier are rated on a fraction of the dc bus voltage and a fraction of the input current. It makes this topology compact and efficient. Power rating, size and losses depend on ratio the dc bus voltage to rectifier voltage (boosting factor). For example, if the boosting factor is low, the efficiency could be 98 to 99%. The proposed boost rectifier has been analyzed and experimentally verified on a 4 kW prototype. The results are presented and discussed.

Currently, the automakers use Lithium-ion battery like an energy storage system for vehicle propulsion. However the battery power is limited by two deferent rates of charge and discharge, what can limit the recovered energy during the brake phase. On the other hand, the supercapacitor is a powerful component which can deliver very high power pulse for the both charging and discharging phases. This paper describes a methodology for designing hybrid supply using Li-ion Batteries and supercapacitors for electric vehicle application taking in the account the energetic characteristics and powers limitations of battery and supercapacitor. The method developed in this paper allows us to estimate the optimal level of hybridization and gives us the best technologies to operate this hybridization. An example which illustrates these ideas is proposed and the sizing results of available energy using a hybrid supply are compared with those obtained using the battery like vehicle supply

This paper presents a new course on lighting systems in a French non-specialized engineer school. This course was conceived to increase student attractiveness for power electronics. After two years of unfolding, the conclusions are interesting. A survey has shown that students were not really more interested in power electronics. The only students' plebiscite is the lighting design using DIALux software. The module is described and placed into the context of a non-specialized engineer school. Students' opinion is then analyzed and capitalized to find why power electronics does not look as an interesting subject for these specific engineers.

Matrix (MC) and indirect matrix (IMC) converters are direct three-phase to three-phase power converters providing variable frequency and amplitude control of their output voltage. These converters are compact solutions which can be used on industrial adjustable speed drive applications for induction motors. This paper deals with the comparison of the matrix and indirect matrix converter silicon losses for classical industrial applications with constant RMS current load (similar to a constant motor torque). The indirect matrix converter control is extracted from the matrix converter modulation so as to ensure identical instantaneous modulation. Furthermore, the chosen modulation strategy reduces the IMC losses by allowing zero-current switching on the IMC rectifier stage. This paper presents a new reduced losses modulation adapted for indirect converter based on a modified matrix converter modulation which reduces switching voltage step level during a pulse width modulation period. The losses simulations shows that the power losses peak value is about 20% smaller for the matrix compared to the indirect converter. Hence, the matrix cooling system can be significantly reduced compared to the indirect one. The modified modulation increases the number of gate drivers required from six to twelve in the indirect converter rectifier side in comparison with the classical DPWM modulation, but allows to obtain a 14% decrease of its average losses compared to the classical modulation.

Matrix and two stage matrix converters are direct three-phase to three-phase power converters providing variable frequency and amplitude control of their output voltage. These converters are compact solutions that can be used on industrial adjustable speed drive applications for induction motors. The two stage matrix converter control is extracted from the matrix converter modulation in order to assure the same instantaneous modulation. This paper deals with the comparison of silicon losses for both converters used in classical industrial applications with constant RMS current load, similar to a constant motor torque. Results show that the direct solution is best for efficiency criteria.

This paper proposes a novel method to adapt classical matrix converter modulations to the indirect matrix converter one. This method allows splitting the 3x3 instantaneous matrix of the matrix converter into two instantaneous matrixes 3x2 controlling the rectifier and the inverter of the indirect converter. The proposed method is based on a complete analysis of the classical space vector modulations of the matrix converter. This method is validated by Matlab-Simulink® simulations.

The utilization of the simulation tools to predict Electromagnetic Interferences (EMI) of the power converters is a necessary step in the conception of the system. This paper describes the high frequency behavior modeling method of an Adjustable Speed Drive (ASD) that will be used to estimate the conducted emissions. In order to study the influence of various elements of the ASD on the EMI level, it is necessary to use a precise model of the PWM inverter, energy cable and AC motor, which take into account various phenomena that appear when the frequency increases. In this study only the common mode emissions are considered. To model the PWM inverter, three equivalent common mode noise sources corresponding to inverter switches are used and that will be modeled using a trapezoidal voltage generator using average values of the rise and fall times over a PWM inverter period. The high frequency current that appears in the system is essentially caused by common mode capacitances between the energy cable + motor and ground. A model of the cable has been proposed and validated in the frequency domain for two different lengths. The obtained high frequency ASD model is used to estimate the conducted emissions on all inverter functioning period. In this study SPICE is used to simulate the system in the time domain. The comparison of measured and simulation results of conducted emissions (with LISN) shows a good concordance. One can conclude that the proposed ASD behaviour model gives results with an acceptable precision and with reasonable simulation duration.

The utilization of the simulation tools to predict Electromagnetic Interferences (EMI) of the power converters is a necessary step in the conception of the system. This paper describes the high frequency behavior modeling method of an Adjustable Speed Drive (ASD) that will be used to estimate the conducted emissions. In this study only the common mode emissions are considered. To model the PWM inverter, three equivalent common mode noise sources corresponding to inverter switches are used and will be modeled using a trapezoidal voltage generator using average values of the rise and fall times over a PWM inverter period.

Understanding and characterizing complex EMI phenomena through accurate converters EMI noise emission models is a necessary first step for achieving an efficient filtering. Some of the existing EMI noise source models are only valid for specific applications. In order to study, by simulation the conducted emissions in PWM inverters with reasonable calculation duration, a behavioural model of EMI noise is necessary. In this paper, two EMI noise source models are proposed. It is used to represent the commutation transients of a power device via an equivalent current or voltage source.

Pulse-width-modulated (PWM) voltage-source inverters are known to provoke high-frequency disturbances in motor-drive applications, especially when long cables are used. Indeed, the parasitic elements of the cable along with steep voltage transitions due to semiconductor switchings are responsible for conducted electromagnetic emissions as well as high overvoltages on the motor terminals. Therefore, several specific PWM schemes have been proposed in order to reduce these phenomena without requiring large passive filters. However, strategies which reduce common-mode currents (main conducted electromagnetic emission) tend to increase the overvoltages generated on the motor. This paper focuses on a new PWM strategy which reduces the common-mode currents generated by three-level inverters. It provides a control algorithm which makes sure that the motor overvoltages never exceed those of conventional strategies, while improving the electromagnetic-compatibility performance of the drive

In adjustable speed drive applications, the switching of the inverter semiconductors generates common mode currents as well as harmful overvoltages on the motor terminals when long cables are used. Consequently, bulky and expensive input and output filters must be used. This work aims at reducing these disturbances from their origin by using a three-level neutral-point-clamped (NPC) inverter controlled with a new pulse-width-modulation (PWM) strategy. Whereas previous common mode noise-reducing strategies usually generate higher overvoltages than conventional ones, the proposed PWM is able to manage both problems thanks to its internal degrees of freedom.

A new carrier-based PWM for the reduction of common mode currents applied to Neutral Point Clamped inverters

Inverters used in adjustable speed drives create common mode voltages with high dv/dt transitions resulting in high frequency common mode currents which flow to the ground through stray capacitances. These common mode currents are known to damage the bearings of electric machines and cause malfunctions in other surrounding electronic devices, and therefore need to be confined by using bulky and expensive electromagnetic compatibility (EMC) filters . The presented work focuses on the three levels neutral-point-clamped (NPC) inverter and proposes a new pulse width modulation (PWM) strategy for the reduction of common mode currents by lowering the number of step variations of the common mode voltage. Unlike previous strategies, this carrier-based PWM pays attention to the real phenomena involved in the generation of common mode currents so as to efficiently reduce them by avoiding dead time effects . The new strategy has been implemented in a 20 kVA prototype and the experimental results presented in this paper confirm its best EMC behavior compared with classical PWM.

Abstract – The studied storage system is composed of a supercapacitor bank and a brake resistor which acts when supercapacitor is full. Moreover the supercapacitor has a series resistor which influences the energetic efficiency. In this paper, three control strategies are presented for a traction application. Two strategies maximize the charge of supercapacitor to increases efficiency. Energetic Macroscopic Representation (EMR) is used to organize the numerous blocks required for modeling and control. Experiment results are provided.

Les sources de stockage hybrides (HESS) utilisent des convertisseurs DC-DC pour assurer le couplage des sources d'énergie. Pour des applications où l’espace disponible pour embarquer la batterie est limité, le volume et la masse de l’électronique de puissance doivent être réduites au maximum. C’est le cas des véhicules électriques. Dans ce travail, une nouvelle architecture de couplage permettant de réduire le volume et la masse du convertisseur est proposée. Cette architecture, basée sur un couplage en série des sources, est comparée aux solutions classiques. Elle permet de réduire très fortement la puissance de dimensionnement de l’électronique de puissance du HESS.

Afin de réaliser des études de stabilité des réseaux MTDC, le développement de modèles d’ordre réduit des convertisseurs s’avère nécessaire. Cet article présente un modèle réduit du convertisseur DC/DC modulaire multiniveaux (M2DC) : une topologie de convertisseur DC-DC non isolée attrayante pour le réseau HVDC. Cet article présente d’abord le convertisseur M2DC. Dans un second temps, le modèle réduit sera développé. Le développement de la commande de ce modèle sera effectué dans la troisième partie. Enfin, la comparaison du modèle réduit et de son contrôle avec le modèle moyen des bras sera effectuée dans la dernière section de l’article.

La méthode du produit des aires est très répandue pour le dimensionnement des composants magnétiques en électronique de puissance, grâce notamment à sa simplicité de mise en œuvre. Néanmoins, l’utilisation de cette méthode nécessite des itérations pour affiner le choix du noyau et la définition des bobinages afin de respecter les contraintes thermiques des composants. Dans cet article, la méthode du produit des aires est étendue pour pouvoir y incorporer la prise en compte des effets haute fréquence et les contraintes thermiques liées aux composants magnétiques planar. L’expression finale obtenue permet un dimensionnement plus efficace et plus rapide des composants planar en évitant les itérations liées aux contraintes thermiques. La différence entre les deux approches est illustrée au travers d’un exemple de dimensionnement de transformateur planar (100 kHz / 2 kW).

Le convertisseur DC-DC Modulaire Multi-niveaux (M2DC) est une topologie attrayante de convertisseur DC-DC non isolée pour les réseaux haute tension à courant continu (HVDC). Cet article présente dans un premier temps, le modèle et la commande du M2DC. Une étude de l’utilisation des degrés de liberté phares est menée dans un second temps pour réaliser une analyse de leurs impacts sur le dimensionnement des éléments du convertisseur tels que les condensateurs de sous modules ainsi que sur les pertes liées aux semi-conducteurs

La conception rapide de prototypes de laboratoire est intéressante pour permettre la validation, à moindre frais, de dimensionnements spécifiques de transformateurs planar. Avec l’apparition des Fabrication Laboratory (FabLab), il devient possible, en utilisant les outils et machines disponibles dans ces derniers, de réaliser de manière assez simple, rapide et peu coûteuse, des prototypes de transformateur planar en technologie feuillard. Cet article présente donc une méthodologie permettant de concevoir ce type de composant, pour des puissances de quelques kilowatts, en utilisant le matériel usuel des FabLab.

Cet article présente une méthodologie permettant l’analyse des densités de puissance volumique qui peuvent être obtenues via l’utilisation de composants magnétiques planar au sein des convertisseurs d’électronique de puissance. En se basant sur une configuration optimale pour le transformateur, les densités de puissance volumique maximales atteignables pour différents noyaux magnétiques EE et E/PLT sont étudiées pour trois types de refroidissement : sans refroidisseur, refroidissement simple face et refroidissement double face. Ce type d’analyse peut être utile à un concepteur, lors d’une phase de dimensionnement, en le guidant vers des choix technologiques adaptés.

L'utilisation de la transmission DC est particulièrement avantageuse pour la transmission à longue distance et l'interconnexion des réseaux AC asynchrones. Plusieurs topologies de convertisseur peuvent être utilisées pour le HVDC. Les convertisseurs modulaires multiniveaux (MMC) sont les plus favorisés étant donné leurs avantages technologiques par rapport aux autres topologies de convertisseurs. Du fait de leur maturité industrielle, ils se sont imposés maintenant pour tous les convertisseurs AC/DC à transistors de forte puissance. Jusqu'ici, ils ont toujours été étudiés avec une source de tension côté DC. Or, lorsqu'ils sont équipés de DC breaker, on associe une inductance en série pour limiter les variations de courant. Ceci a des conséquences en terme de modélisation puis de détermination de la commande. Cet article a pour objectif de proposer une modification de commande afin de prendre en compte cette inductance.

Cet article présente la modélisation et la commande basée sur l’inversion de ce modèle, du Convertisseur Modulaire Multiniveaux DC-DC (MMC DC-DC) en demi-ponts. La structure DC-DC MMC présente beaucoup d’avantages tels que sa modularité, l’absence de condensateur sur le bus DC haute tension et une fréquence de commutation très faible étant donnée le grand nombre de SM. Elle conserve aussi les inconvénients intrinsèques du MMC comme la complexité de modélisation [2] et de contrôle [3] dû au grand nombre de semi-conducteurs et de variables d’état à contrôler. La stratégie de contrôle utilise le schéma de contrôle classique avec contrôle d'énergie et contrôle de puissance pour une partie du MMC DC-DC. La seconde partie utilise le contrôle d'énergie et génère la forme d’onde de la tension du bus triphasé AC liant les deux parties du convertisseur. Le contrôle explicite de la génération de l’onde de tension AC permet de garantir le bon fonctionnement du convertisseur même en cas de creux de tension DC critique sur l’un ou l’autre des bus DC et ainsi évite la nécessité de disjoncteur DC ou d’utiliser un MMC Full bridge. La validité du contrôle proposé est vérifiée par simulation à l’aide de Matlab-Simulink.

L’objectif de cet article est d’analyser le fonctionnement d’une nouvelle topologie de convertisseur DC/DC haute tension (DC/DC Modular Multilevel Converter) dédié au transport de l’énergie électrique HVDC (High Voltage Direct Current). Le contrôle du convertisseur est premièrement discuté au travers d’un modèle mathématique découplé. Le modèle proposé permet de réduire la complexité du contrôle du convertisseur. Afin d’améliorer les performances du convertisseur, le dimensionnement du convertisseur est exploré dans un second temps. Enfin, des résultats de simulation illustrent le fonctionnement et les performances du nouveau convertisseur DC/DC basé sur le modèle découplé proposé.

Les composants magnétiques planar sont de plus en plus présents dans les convertisseurs de puissance en remplacement des composants bobinés classiques. L’aspect thermique de ces composants est essentiel pour un fonctionnement correct des structures de puissances. Dans cet article, un modèle thermique de transformateurs planar, basé sur un réseau nodal de résistances thermiques (RRT), est développé. Ce réseau est appelé structurel car toutes les résistances thermiques sont directement en lien avec la géométrie du composant. Les résultats de ce modèle seront comparés à des résultats issus de simulations par éléments finis ainsi qu’à des mesures expérimentales sur un prototype.

La technologie planar est une solution intéressante pour les composants magnétiques haute fréquence (HF) dans les alimentations à découpage. La miniaturisation des composants de puissance liée à leur montée en fréquence a permis le développement, depuis quelques décennies, des composants magnétiques planar, notamment dans les systèmes embarqués à forte densité de puissance. Dans l’optique d’optimiser les inductances et transformateurs planar, chaque aspect de leur géométrie est à prendre en considération. Cet article mettra l’accent sur l’un de ces aspects : la forme des angles des pistes de circuit imprimé (PCB). Trois formes standards de pistes avec différents angles seront simulées par éléments finis 3D pour évaluer leurs résistances dynamiques (AC) et leurs facteurs résistifs. Différentes combinaisons de ces formes élémentaires seront ainsi testées et comparées, et l’influence des angles des pistes sera soulignée.

La prédétermination, dans la phase de dimensionnement, des pertes et des valeurs d’inductances est nécessaire à l’élaboration de composants magnétiques performants pour l’électronique de puissance. La modélisation numérique peut être utilisée pour déterminer les caractéristiques propres d’un composant notamment lorsque sa géométrie est "complexe" ou que la fréquence d’utilisation est élevée. Ces modèles sont très précis mais le temps de simulation nécessaire est important par rapport à des modèles analytiques plus simplistes. Les méthodes de réduction de modèles, type POD ou autres, permettent de diminuer le nombre de ces simulations numériques tout en conservant une grande précision.

As part of the More Electric Aircraft (MEA), aeronautics manufacturers are moving towards switching-mode power supplies (SMPS) solutions with high power density (until 15kW/kg for electrical car [3]) to replace pneumatic and hydraulic actuators. These power electronic devices have two main advantages: Firstly, they reduce the mass of conventional equipments and secondly, they also reduce the fuel consumption by a few percent. These improvements were made possible thanks to the evolution of electronic component manufacturing techniques that lead to the miniaturization of electrical equipment in recent decades. In power electronics, whether in automotive or aerospace, the trend is increasingly towards these integrated solutions, compact with high power density. Inside power converter, planar components, made of PCB (Printed Circuit Board) or with copper foil, fit into this context and offer an interesting alternative to conventional High Frequency transformers. They offer excellent electromagnetic and thermal characteristics [2]. They can also be integrated easily inside electrical circuits and have good rigidity, good repeatability and good modularity that make easier their industrialization (automated mass production) [1]. The optimized design of such component (losses, volume and mass) is essential for a better power density of all of the power converters. Based on analytical expressions and finite element models (FEM), this PhD work deals with the development of optimized planar components for aeronautics. Different configurations of planar transformer windings are studied in order to reach some objectives such as the fewest losses (including skin and proximity effects), a controlled and optimized leakage inductance value, a reduction of the parasitic capacitances (linked to transformer’s resonance) and a weak EMC (Electromagnetic Compatibility) impact in a given environment.

La pré-détermination des valeurs de pertes et d’inductances est nécessaire à l’élaboration de composants magnétiques performants pour l’électronique de puissance. Leurs caractéristiques propres, variant en fonction de la fréquence, doivent être déterminées de manière précise sur une large gamme de fréquences, idéalement jusqu’à 30MHz pour tenir compte des aspects CEM. Dans la littérature, des simulations éléments finis 2D sont largement utilisées pour ce type de calcul. Ces modélisations servent généralement de référence pour le développement de modèles analytiques, notamment pour le cas spécifique des pertes cuivre. L’étude en 3D de ce type de composant est encore très peu développée car elle engendre des problèmes de modélisation, de ressources informatiques et de temps de calcul. Dans cet article la comparaison en termes de performances et de précisions pour des modèles d’inductances planar en 2D et en 3D est présentée. Les résultats obtenus sont comparés à des mesures d’impédances sur des prototypes.

L'un des principaux verrous technologiques dans le domaine des véhicules propres est lié à la source de stockage de l'énergie électrique. C’est dans ce contexte que les constructeurs se mobilisent pour améliorer les technologies de batteries et pour prédire précisément leurs comportements. Le travail proposé ici traite de la modélisation de sources de stockage hybrides composées d'une association batterie lithium-ion et supercondensateurs. L'objectif est de permettre la prise en compte du vieillissement des composants de ce système. Le développement d'un modèle incluant les aspect électrique et thermique permet d'évaluer la dégradation progressive des performances des sources du système. Les résultats de simulation montrent les performances du modèle actif pour une source hybride et confirment la faisabilité de notre démarche. L'outil ainsi développé est destiné à comparer les méthodes de gestion des sources dans un système de stockage hybride mais également à en développer de nouvelles en intégrant le paramètre de durée de vie pour la conception de ces systèmes.

Cet article présente la mise en place d’une commande par hystérésis simple et originale permettant de contrôler un convertisseur en maitrisant indirectement sa fréquence moyenne de commutation. Cette commande est basée sur la connaissance de l’état du convertisseur et la mise en place de règles de choix de commutations simples à mettre en œuvre. Ceci est appliqué à un onduleur triphasé relié au réseau à facteur de puissance unitaire. Les « pertes silicium » obtenues sont similaires à celles produites par les modulations naturelles à fréquence fixe pour une même qualité de courants sur le réseau, avec des familles d’harmoniques moins concentrées. A l’heure où les convertisseurs voient leur fréquence augmenter, cela peut être une voie d’exploration de commandes plus rapides et plus facilement intégrables par utilisation de composants logiques programmables, dont les capacités ne cessent de croitre.

Cet article présente une amélioration des performances d’un convertisseur matriciel par utilisation de degrés de liberté naturellement accessible au niveau de la matrice de conversion. Ces améliorations sont réalisées à partir d’un modulateur simple et synthétique, basé sur l’introduction d’un convertisseur virtuel. On présente tout d’abord une méthode de généralisation de la matrice de conversion obtenue avec une modulation classique. Cette matrice est modifiée afin d’induire la modification de la phase de roue libre. Un choix approprié est effectué et on réalise alors l’étude des pertes silicium du convertisseur. Les performances du convertisseur utilisant la modulation proposée et celle utilisée classiquement dans la littérature sont comparées. La méthodologie de calcul des pertes silicium est présentée ainsi que la validation fonctionnelle de cette nouvelle modulation par des relevés expérimentaux réalisés sur un prototype laboratoire.

L’objectif de cet article est de présenter une nouvelle méthode de contrôle par hystérésis d’un onduleur à Modulation de Largeur d’Impulsion (MLI) triphasé. Avec cette méthode, les inconvénients des stratégies par hystérésis issues de la bibliographie sont dissipés. Pour la stratégie par hystérésis basique dite bang-bang, deux problèmes majeurs sont observables. Le premier concerne des sorties de bande des erreurs pouvant atteindre deux fois la largeur de la bande d’hystérésis. Le second est un déséquilibre du nombre de commutation entre les trois bras du convertisseur. Quant aux stratégies utilisant une transformation des trois courants de phase en (α, β), le problème réside dans des valeurs de Taux de Distorsion Harmonique en courant (THDi) différentes entre les trois courants de ligne. Avec cette nouvelle méthode, tous ces désavantages ne sont plus occasionnés. De plus, la comparaison à même THDi des pertes entre cette nouvelle méthode, la stratégie par hystérésis basique, celle en (α, β) et deux commande MLI en tension par porteuse révèle que notre commande est parmi celle engendrant le moins de pertes

Cet article propose un modulateur simple et synthétique adapté au convertisseur matriciel, basé sur l’introduction d’un convertisseur virtuel. Le but de ce travail est de construire une Modulation de Largeur d’Impulsion (MLI) simple et générale pour le contrôle des convertisseurs matriciel industriel. La solution proposée est équivalente à une modulation vectorielle (SVM) particulière. Cette solution prend en compte les harmoniques et le déséquilibre des tensions d’entrée et permet de générer un ratio en tension maximale identique aux modulations classiques (86%). Cet article présente tout d’abord la méthode de calcul de la modulation moyenne d’un convertisseur virtuel puis la modulation naturelle associée au convertisseur matriciel, l’ensemble étant validé par des relevés expérimentaux.

Le rendement des alimentations sans interruption est un critère de conception essentiel. L’apparition de multiples topologies de conversion multi-niveaux pose la question de leur impact sur le rendement. Cette étude s’intéresse au dimensionnement des convertisseurs d’une alimentation sans interruption, quel que soit le nombre de niveaux de tension. Une méthode d’analyse est décrite, basée sur l’expression des courants circulants dans une topologie multi-niveaux générique. Les résultats permettent de choisir une structure appropriée à la cible de rendement et de prix. Ces résultats dépendent des contraintes de l’application et des composants existants.

Du fait de leur utilisation permanente, le rendement des alimentations sans interruption (ASI) est un critère primordial. D’après les contraintes de cette application, il ressort de la bibliographie que le principe du pôle résonant auxiliaire (ARCP) présente de nombreux avantages. L’utilisation dans ce cadre d’un autotransformateur diminue les pertes auxiliaires, améliore le dimensionnement et simplifie la commande. Un pôle résonant simplifié a été développé à la fois pour le redresseur et pour l’onduleur (à trois niveaux de tensions). Les compromis de dimensionnement sont explicités. Pour valider cette topologie, un prototype d’ASI de 125 kVA a été développé et testé

L’objet de cet article concerne l’étude des perturbations électromagnétiques conduites générées par les convertisseurs statiques. L’objectif est de proposer une démarche permettant d’analyser l’influence du pont redresseur à diodes sur la propagation des perturbations conduites de mode commun et de mode différentiel vers le réseau électrique. Pour réaliser cette étude, des modèles haute fréquence du réseau électrique et du système de conversion statique ont été proposés. Les résultats de ce travail permettront l’optimisation du dimensionnement du filtre CEM à mettre à l’entrée du convertisseur en fonction des impédances réseau et

Cet article présente une nouvelle stratégie de modulation de largeur d’implusion (MLI) destinée à réduire les courants de mode commun générés dans les applications de variation de vitesse utilisant un onduleur à trois niveaux de type neutral-point-clamped (NPC). Il détaille le principe de la commande et son implantation dans un processeur par un modulateur à porteuses en dents de scie. Celui-ci permet de contrôler les degrés de liberté apportés par la stratégie.

Cet article présente le fonctionnement des onduleurs Z-source. Ils utilisent un réseau d’impédance pour coupler l’onduleur à la source de tension continue. Ce réseau d’impédance est constitué d’une structure L C hybride croisée. Il permet à l’onduleur d’amplifier la tension de sortie grâce à une commande spécifique, ce qui le rend équivalent à la mise en cascade d’un hacheur survolteur avec un onduleur classique. L’étude du principe de fonctionnement ainsi qu’une comparaison avec une structure classique équivalente montreront les limites de cette structure récemment introduite.

Les composants magnétiques planar sont de plus en plus présents dans les convertisseurs de puissance en remplacement des composants bobinés classiques. L’aspect thermique de ces composants est essentiel pour un fonctionnement correct des structures de puissances. Dans cet article, un modèle thermique de transformateurs planar, basé sur un réseau nodal de résistances thermiques (RRT), est développé. Ce réseau est appelé structurel car toutes les résistances thermiques sont directement en lien avec la géométrie du composant. Les résultats de ce modèle sont comparés à des résultats issus de simulations par éléments finis ainsi qu’à des mesures expérimentales sur un prototype.

L'invention concerne un système de stabilisation d'une tension d'alimentation d'un réseau électrique de bord d'un véhicule automobile, du type de ceux limitant une variation de tension d'une source de tension alimentant ledit réseau lors de l'activation d'un équipement électrique dudit véhicule relié audit réseau, ledit système comprenant : - une première unité de limitation du courant circulant entre ladite source de tension et ledit équipement, ladite unité étant configurée de sorte à limiter le courant circulant entre la source de tension et l'équipement électrique en fonction d'une variation de tension de la dite source de tension; - une deuxième unité de limitation du courant circulant entre ladite source de tension et ledit équipement, ladite unité étant configurée de sorte à limiter le courant circulant entre la source de tension et l'équipement électrique à un seuil de courant.

La présente invention concerne un dispositif d'alimentation d’un réseau électrique d'un véhicule automobile comprenant une première et une deuxième batterie et un convertisseur de tension continue comprenant une première borne reliée à la première batterie et une deuxième borne reliée à la deuxième batterie, la deuxième borne étant également destinée à être connectée au réseau électrique, dans lequel le convertisseur de tension continue est configuré pour réaliser une source de courant disposée en série entre la première et la deuxième batterie de façon à contrôler le courant échangé avec la première batterie.

L’invention concerne un système de stabilisation d’une tension d’alimentation (Ubat) d’un réseau électrique de bord d’un véhicule automobile, du type de ceux limitant une variation de tension d’une batterie alimentant ledit réseau au moment de l’activation d’un équipement électrique dudit véhicule relié audit réseau, caractérisé en ce qu’il comprend : - une résistance variable en fonction de ladite variation de tension connectée en série avec ladite batterie et ledit équipement ; - une résistance constante en parallèle de ladite résistance variable.

Le procédé selon l’invention est du type de ceux consistant à limiter une variation de tension d’une batterie alimentant le réseau électrique de bord au moment d’un démarrage d’un moteur thermique du véhicule au moyen d’un démarreur 10 électrique relié au réseau. Conformément au procédé de l’invention, un élément résistif présentant une résistance choisie en fonction de la variation de tension parmi un ensemble discret de valeurs prédéterminées (RDSon1, RDSon2, RDSon3, RDSon4) est connecté en série avec la batterie et le démarreur. Selon une autre caractéristique de l’invention, les valeurs prédéterminées (RDSon1, RDSon2, RDSon3, RDSon4) de l’ensemble discret de valeurs prédéterminées sont proportionnelles à un nombre prédéterminé des premiers termes d’une série harmonique (1, 1/2, 1/3 et 1/4).

Le système selon l’invention est du type de ceux limitant une variation de tension d’une batterie alimentant le réseau électrique de bord au moment d’un démarrage d’un moteur thermique du véhicule au moyen d’un démarreur électrique relié au réseau. Conformément à l’invention, il est prévu une résistance variable en fonction de la variation de tension, cette résistance variable étant connectée en série avec la batterie et le démarreur. Selon une autre caractéristique, la résistance variable est contrôlée par une boucle de courant principale en fonction d’une intensité de référence (Iref) générée par une boucle de tension en fonction de la variation de tension par rapport à une tension de référence (Uref). La résistance variable est typiquement formée de plusieurs transistors de puissance en parallèle.

The method involves performing synchronization and phasing steps permitting to implement control voltage vector at frequency and a turning voltage vector defined by exact connection between three input phases (u, v, w) and three output phases (a, b, c) of a speed variator. The control voltage vector is amplified beyond 87 percent of amplitude of input voltages (Vun, Vvn, Vwn) and until reaching amplitude of the turning voltage vector, where the input phases are connected to an alternative voltage source applying the input voltages between the input phases and the output phases. An independent claim is also included for a direct matrix converter type speed variator comprising a control unit for amplifying a control voltage vector.

The invention relates to a control method implemented in a variable speed device of the matrix converter type, comprising: three input phases (u, v, w) connected to an AC voltage source and three output phases (a, b, c) connected to an electrical load, nine two-way current and voltage electronic switches (fau, fav, faw, fbu, fbv, fbw, feu, fev, fcw) intended to be individually controlled in order to connect an output phase to any one of the input phases, the operation of switching the switches of the converter obeying a duty cycle matrix for obtaining an output voltage at the load, said duty cycle matrix including a zero phase, the method including a step of suppressing the zero phase in the duty cycle matrix and a step of positioning a new zero phase in the duty cycle matrix so as to minimize the switching losses and the common-mode voltages

The invention relates to a control method implemented in a matrix converter variable speed drive, comprising: three input phases (u, v, w) connected to an alternating voltage source and three output phases (a, b, c) connected to an electric charge, nine bidirectional current and voltage electronic switches (fau, fav, faw, fbu, fbv, fbw, fcu, fcv, fcw) distributed among three switching cells (A, B, C) and to be individually controlled for connecting an output phase to any of the input phases, wherein the switching between the switches of the converter is contingent upon a real matrix of duty cycles used for obtaining an output voltage towards the charge, the real matrix of duty cycles being determined from a virtual matrix (Mv) of a virtual converter (20) comprising three switching cells (A’, B’, C’), one of the switching cells of the virtual converter being permanently blocked.

Correspond à la 3ème architecture d’utilisation d’un super-condensateur pour récupérer l’énergie du moteur en mode freinage. Avantages : économie d’énergie, réduction du taux distorsion THDI, augmentation (boost) et lissage de la tension du bus continu. Dans cette architecture, la tension du super-condensateur n’est pas liée à la tension du bus continu, d’où diminution de la taille des transistors.

Correspond à une des architectures permettant l’utilisation d’un super-condensateur dans un variateur pour récupérer l’énergie du moteur en mode freinage. Avantages : économie d’énergie, réduction du taux distorsion THDI, augmentation et lissage de la tension bus continu.

Variateur de vitesse comportant un super-condensateur pour stocker l’énergie lors du freinage de la charge. Selon les différents modes de fonctionnement du variateur, un convertisseur DC/DC permet de contrôler le courant circulant dans le super-condensateur, notamment pour obtenir un THDI faible pour le courant réseau.

méthode de modulation permettant de limiter les perturbations CEM engendrées par la modulation des convertisseurs MLI

methode de modulation permettant d’agir sur les montages NPC pour contrôler l’équilibrage du bus continu et limitater les pertes par commutation de l’onduleur MLI

méthode permettant par action sur la composante homopolaire de minimiser les pertes dans les onduleurs MLI à n bras

Common mode voltages generated by adjustable-speed drives create common mode currents which damage electric machines and require expensive filters. Usual ways to cope with this issue are based mainly on filtering and designing appropriate converters. However, recent development on power electronics shows that solutions can also be developed on PWM strategies. Thus, the presented work aims at elaborating a suitable PWM strategy for the reduction of common mode currents in three levels Neutral-Point-Clamped (NPC) inverters. The proposed new PWM appears to be a compromise solution between the quality of low frequency voltage supply (output Total Harmonic Distortion: THD) and high frequency conducted emissions (Electro-Magnetic Compatibility: EMC). The principle of the method is to lower the number of variations of the common mode voltage by introducing simultaneous commutations, so that the common mode voltage is not affected during the switching. As a consequence, the associated common mode current of the commutations is cancelled. The particularity of this PWM strategy, compared with previous ones, is that the double commutation is permanently controlled and adapted so as to ensure its perfect synchronism by avoiding dead time effects. The novel strategy has been implemented on an experimental bench using a carrier-based modulator and validated through common mode current measurements in both temporal and frequential domains. This research results from a co-operation between Schneider Electric, STIE (Schneider Toshiba Inverter Europe) and the L2EP (Laboratoire d’Electrotechnique et d’Electronique de Puissance de Lille), and focuses on the theme of adjustable-speed drives with reduced electromagnetic emissions. It is financed by Schneider Electric for one part and by the French State and the Région Nord-Pas-de-Calais for the other part. The new PWM strategy has been the subject of a patent deposit from Schneider Electric in 2006.

Pour régler la puissance débitée par une source triphasée dans un récepteur, il est habituel d'utiliser un gradateur triphasé à 6 thyristors. La structure présentée, appelée gradateur économique, permet la suppression de deux thyristors d'une même phase. Cette dissymétrie structurelle entraîne un déséquilibre sur la charge pour les deux types de commande usuels : 1) variation de l'angle de phase; 2) trains d'ondes. La variation symétrique de l'angle de phase, bien que permettant un réglage de la puissance globale dissipée dans le récepteur, introduit un déséquilibre. Il est cependant possible d'améliorer les performances du système en utilisant une commande dissymétrique. Commandé par trains d'ondes et dans les conditions usuelles d'utilisation, il est peu perturbé par la dissymétrie structurelle. De plus, cette structure permet la mise en oeuvre d'une commande simple, la troisième phase servant naturellement de retour à la source. L'utilisation du gradateur économique, dans une structure insérant un transformateur entre le gradateur et la charge, peut être envisagée à condition d'adopter une stratégie de commande prenant en compte les contraintes apportées par le transformateur. Enfin, une synthèse sur les perturbations induites sur le réseau par les gradateurs utilisés pour le chauffage électrique, montre l'avantage de la commande par trains d'ondes