Fiche individuelle

This paper intends to present a methodology to maximise reuse of regenerative braking energy in automatic metro lines for both offline and real time energy management. It first describes optimisation techniques for scheduling energy efficient timetables, while considering a no-fluctuation operating mode, as it corresponds to the most dominant operating case. Impact of headway and dwell time management on regenerative braking recovery are especially examined with a multi-criteria fitness function. Then, iterative solving techniques are introduced to precisely quantify energy transfers between trains. A neural estimator of trains power consumption is also proposed to meet real time requirements. Simulation results based on experiments conducted on Torino metro line are exposed to evaluate the performance of this estimator.

This paper proposes a methodology to design a supervision system (SS) based on Fuzzy and Boolean logics. In the first stage, a graphical modeling tool is used to facilitate the analysis and the determination of Fuzzy–Boolean algorithm linked to the test system. To improve the performance of the proposed SS a genetic algorithm (GA) is implemented in the second stage. The SS objective is used to control electric vehicles (EVs) load in order to minimize the energy transmission costs (ETC) of the distribution system operator (DSO). To achieve this goal, it is necessary to promote local consumption of wind and photovoltaic (PV) power by coordinating them with EVs load, maximize EVs charging during cheaper energy periods and reduce subscribed power exceeding. The performance of the SS is shown by numerical simulation results using Matlab/Simulink. Finally, a Matlab–PowerFactory co-simulation framework is proposed in order to assess supervision system influence on the technical aspects of a real test grid.

Renewable energy sources and storage units’ integration in the railway power substations is an alternative solution to handle the energy consumption, due to railway traffic increase and electricity market liberalization. To integrate this technology change in the railway network, an adapted energy management system has to be established. However, when considering only energy efficiency aspects on the energy management strategy, an economical viable solution cannot be ensured. This paper proposes a supervision strategy based on multi-criteria approach including energetic, environmental and economic constraints. The energy management objectives such as reducing the network power demand, favoring local renewable consumption and ensuring storage availability are treated in different time levels. Economic aspects are first integrated in predictive mode based on forecast data. Then a supervision strategy is developed based on fuzzy logic approach and graphical tool to build it. An optimization study of the supervision strategy is proposed in order to conclude on system performance. Simulation results are discussed for different scenarios cases and the reaction of the hybrid railway power substation is detailed. Results show that this methodology can be successfully applied for hybrid systems energy management in order to improve their energy efficiency.

he aim of the paper is to propose an approach for statistical assessment of the potential of plug-in electric vehicles (PEV) for vehicle-to-grid (V2G) ancillary services, where it focuses on PEVs doing daily home-work commuting. In this approach, the possible ancillary services (A/S) for each PEV fleet in terms of its available V2G power (AVP) and flexible intervals are identified. The flexible interval is calculated using a powerful stochastic global optimization technique so-called ‘‘Free Pattern Search” (FPS). A probabilistic method is also proposed to quantify the impacts of PEV’s availability uncertainty using the Gaussian mixture model (GMM), and interdependency of stochastic variables on AVP of each fleet thanks to a multivariate modeling with Copula function. Each fleet is analyzed based on its aggregated PEV numbers at different level of distribution grid, in order to satisfy the ancillary services localization limitation. A case study using the proposed approach evaluates the real potential in Niort, a city in west of France. In fact, by using the proposed approach an aggregator can analyze the V2G potential of PEVs under its contract.

This study focus on the minimum duration of training data required for PV generation forecast. In order to investigate this issue, the study is implemented on 2 PV installations: the first one in Guadeloupe represented for tropical climate, the second in Lille represented for temperate climate; using 3 different forecast models: the Scaled Persistence Model, the Artificial Neural Network and the Multivariate Polynomial Model. The usual statistical forecasting error indicators: NMBE, NMAE and NRMSE are computed in order to compare the accuracy of forecasts. The results show that with the temperate climate such as Lille, a longer training duration is needed. However, once the model is trained, the performance is better.

This paper is focused on the design and the implementation of a hybrid PV-wind power system with batteries. It aims to emulate the behavior of a hybrid power system in order to face load consumption variations. Final system includes relevant contributions such as quality of emulator (a large number of parameters are considered); capacity to study various impacts simultaneously, a fast dynamic and a set of experimental tests that have been achieved and validated with a test bench. Moreover, a relevant supervision strategy based on currents control and batteries State Of Charge (SOC) estimation has been successfully performed despite simplicity of converter controls.

In recent years, automobile industries focus on the electrification and hybridization of the vehicle’s production. The number of Plug in Electric Vehicles (PEV) and Plug in Hybrid Electric Vehicles (PHEV) are significantly increasing through the next years. These raises impose negative impacts on the electrical power grids. In this study, a supervision system is proposed with the aim of reducing the power losses and voltage profile improvement, thanks to a dynamic programming optimization algorithm. V2G (Vehicle to Grid) technology is introduced as benefits of vehicle electrification for electrical distribution grids.

The embedded power systems are nowadays developing at high pace. Hybrid-electric vehicles, full- electric vehicles, airplanes, ships, high-speed trains, all share a common point – the embedded electrical power system. This paper aims to present an optimization methodology of a fuzzy-logic supervision strategy. The optimization objectives are to minimize the DC-link voltage variations, and to increase the system efficiency by reducing the dissipated power. For that, a methodology involving the experimental design and genetic algorithm will be presented. The simulation and experimental results are validating the proposed procedure.

Hybrid Energy Sources based on Storage Systems (HES) are increasingly used to improve the grid integration of renewable energy generators, or to improve the energy efficiency and the reliability of transport systems. This paper proposes a survey on the methodologies to design fuzzy logic based supervision strategies of this new kind of energy generating systems. Different ways to manage energy storage system are particularly discussed. A graphical modeling tool is used to facilitate the analysis and the determination of fuzzy control algorithms adapted to complex hybrid systems. The methodology is divided in different steps covering the design of a supervisor from the system work specifications to an optimized implementation of the control. An Experimental Design Methodology (EDM) combined with optimization algorithms is used to tune a set of parameters suitable for a fuzzy supervisor in order to optimize power, energy, efficiency, voltage quality, economic or environmental indicators. The application of this methodology to the supervision of different topologies of HES, based on renewable energy in a grid or in building applications or dedicated to transport systems, illustrates the performance and the systematic dimension of the approach.

This paper presents an energy management strategy for a commercial building in supermarket application. Some objectives are established as load shedding, to reduce the electricity bill and the CO2 emissions of commercial building, using photovoltaic (PV) and storage systems. An energy management supervision strategy based on the rules of the electricity bill will be presented. This paper focuses on the supervision strategy with the help of fuzzy logic and a graphical methodology to build it. It is shown, with the help of simulations and some economic and ecological indicators that the energy bill cost and the CO2 emissions can be reduced by using the proposed solution

With the growth of wind energy for power generation, several Transmission System Operators (TSO) have increasing difficulties to forecast congestions due to the unpredictable nature of the energy source. This paper proposes to enhance congestion management using a real time supervisor. This supervisor performs automatic and dynamic re-dispatchings using both variable speed wind generators and conventional generators. In order to minimize production constraints, the real time congestion management system is based on an indicator of the efficiency of a re-dispatching on the power flowing in an overloaded line. This approach leads to reduced re-dispatching costs and increased network reliability. The simulation of the IEEE 14-bus test power system enhanced by the supervision system is done using the software “EUROSTAG”. Grid integration of renewable generation is therefore increased through renewable production maximization while ensuring network security.

The local DC Power Distribution System of More Electric Aircraft is one of the cores of the electric power transmission. Because the mechanical source (Turbine Engine) is unidirectional, the system is not totally reversible. Some storage and dissipation systems are necessary to store or/and dissipate the returned energy to maintain the DC bus voltage. Different power management strategies are proposed and compared. The development of experimental test benches is necessary to validate these strategies. In this paper, we present a 3kW test bench, emulating a unidirectional source that supplies a bidirectional load with the help of a hybrid system using supercapacitors and a dissipation system. The experimental validation of the power management strategies is presented in this paper too.

Hybrid Renewable Energy Systems (HRES) are increasingly used to improve the grid integration of wind power generators. The goal of this work is to propose a methodology to design a fuzzy logic based supervision of this new kind of production unit. A graphical modeling tool is proposed to facilitate the analysis and the determination of fuzzy control algorithms adapted to complex hybrid systems. To explain this methodology, the association of wind generators, decentralized generators and storage systems are considered for the production of electrical power. The methodology is divided in six steps covering the design of a supervisor from the system work specifications to an optimized implementation of the control. The performance of this supervisor is shown with the help of simulations. Finally, the application of this methodology to the supervision of different topologies of HRES is also proposed to bring forward the systematic dimension of the approach.

The local DC Power Distribution System of More Electric Aircraft is one of the cores of the electric power transmission. Because of some unidirectional devices (diode bridge and anti-run-back diodes), the system is not totally reversible. Some storage and dissipation systems are necessary to store or/and dissipate the returned energy to maintain the DC bus voltage and to increase the energy efficiency. This paper introduces four supervision strategies in two levels to maintain the DC bus voltage and compares these strategies with the help of two criteria: the voltage performance and efficiency.

Flywheel energy storage systems (FESSs) improve the quality of the electric power delivered by wind generators, and help these generators contributing to the ancillary services. Presently, FESSs containing a flux-oriented controlled induction machine (IM) are mainly considered for this kind of application. The paper proposes the direct torque control (DTC) for an IM-based FESS associated to a variable-speed wind generator, and proves through simulation and experimental results that it could be a better alternative. This DTC application entails two specific aspects: 1) the IM must operate in the flux-weakening region, and 2) it must shift quickly and repeatedly between motoring and generating operation modes. DTC improvement for increasing the FESS efficiency, when it operates at small power values, is discussed. Some aspects concerning the flywheel design and the choice of the filter used in the FESS supervisor are also addressed.

The work presented in this paper analyses, with the help of experiments on a 2,2 kW test bench, the possibility to participate in the primary frequency control with a variable speed wind generator. A power reserve is obtained with the help of the generator torque control by following a power reference value lower than the maximum power which must be extracted from the wind. This approach allows also using a part of the kinetic energy in the blades inertia to contribute to this reserve. The dynamic tests carried out on the test bench, by using medium and high variable wind speeds, confirm the capacity of the Wind Turbine Generator (WTG) to participate in the primary frequency control.

In this paper, a primary frequency control strategy based on fuzzy logic, designed for variable speed wind generators, is proposed and tested on a 2.2 kW test bench. The fuzzy logic supervisor ensures a regular primary reserve for a large range of wind speeds without any wind speed measurement. This supervisor controls simultaneously the generator torque and the pitch angle to keep the primary reserve; it determines in real time the generator power reference value. The fuzzy logic supervisor is compared to a simpler strategy, based only on the control of the generator torque. This classical strategy ensures a regular power reserve only when the wind generator operates at full load, and the generator power reference needs to be determined previously or by the network manager. A procedure for implementing a fuzzy logic supervisor in real time is proposed. The experiments indicate the regularity of the power reserve and the ability to contribute to frequency control.

Pour maintenir une réserve de puissance afin de contribuer au réglage primaire de la fréquence avec un générateur éolien à vitesse variable, deux stratégies de commande sont proposées : une stratégie basée sur le contrôle du couple et une stratégie de commande multivariable basée sur la logique floue. La première stratégie, et la plus simple, permet de maintenir une réserve de puissance régulière uniquement lorsque le générateur éolien fonctionne à pleine charge et nécessite une détermination a priori de la puissance de référence par le gestionnaire du réseau. La seconde stratégie permet de dépasser ces limites sans mesure ou prédiction du vent. Le principal résultat de cet article est de montrer qu’il est possible de maintenir une réserve de puissance quelque soit la vitesse du vent.

This paper presents a hardware implementation of the participation of a wind turbine to network primary frequency control. The increase of renewable production of electricity requires the participation of these generators to ancillary services. The proposed method, by actions on the pitch angle and the generator torque through fuzzy logic controllers, creates a power reserve. This reserve is regular on a large range of wind speeds and is constituted without any wind speed measurement. Furthermore, the proposed strategy uses this reserve in case of frequency deviation to provide additional active power to stabilise the electrical grid. The implementation of such strategy on a 2.2kW test bench representing a wind turbine and its generator validates the practical feasibility of the method. Finally, the regularity of the reserve is shown to be weakly dependant on the dynamics of the wind turbine controls.

The flywheel energy storage systems (FESSs) are suitable for improving the quality of the electric power delivered by the wind generators and to help these generators to contribute to the ancillary services. This paper investigates the energetic performances of a low-speed FESS with a classical squirrel-cage Induction Machine (IM) in the aim of its association to a wind generator.

The flywheel energy storage systems (FESSs) are suitable for improving the quality of the electric power delivered by the wind generators and for helping these generators to contribute to the ancillary services. Supervisors must be used for controlling the power flow from a variable-speed wind generator (VSWG) to the power grid or to an isolated load. This paper investigates the control method and the energetic performances of a low-speed FESS with a classical squirrel-cage induction machine in the view of its association to a VSWG. A test bench is developed and experimental results are presented and discussed.

In this paper, the modelling of an autonomous variable speed micro hydropower station is presented. It is composed of a doubly fed induction generator linked mechanically and electrically to a permanent magnet synchronous machine which may recover or supply the slip power and which feeds the DFIG with its magnetizing reactive power leading to classical capacitor removing. The model lies on a classical approach, based on a Park representation, and on an Energetic Macroscopic Representation (EMR). In its first part, this paper develops the modelling principles and underlines the complementarity of both approaches. The control strategy is then depicted in the case of passive loads supplying. Finally, some simulation results are showed and commented.

After a brief review of hydroelectricity allowing to describe the context of our study and the advantages of such a renewable primary energy, this article presents current and classical technical features, implying fixed speed operation, of small hydraulic plants. Subsequently, a variable speed micro hydropower station is presented. It is composed of a doubly fed induction generator linked mechanically and electrically, by way of back-to-back power electronics converters connected to its rotor, to a permanent magnet synchronous machine which may recover or supply the slip power. The DFIG is fed by the rotor with its magnetizing reactive power leading to classical capacitor bank removing and to better voltage regulation. These features allow the station to be autonomous which is interesting in the case of isolated loads supplying. The model and controls of this plant are depicted and a simulation is carried out under variable inductive loads conditions.

This paper discusses about the management of storage systems and loads which can offer some storage capacities. A methodology based on fuzzy logic is presented in this paper and is applied at different practical cases: variable speed wind generator associated with a flywheel energy storage system, energy management strategy for commercial building and finally, coordinated integration of electric vehicle and wind power in electrical network.

Les systèmes multisources intégrant du stockage d’énergie contribueront à faciliter l’intégration croissante des énergies renouvelables dans les réseaux électriques. L’objectif de cet article est de proposer une méthodologie de développement du superviseur d’une unité multisource à l’aide de la logique floue. Un outil graphique est proposé pour faciliter l’analyse et la détermination des algorithmes flous bien adaptés aux systèmes hybrides complexes. Pour expliquer la méthodologie, l’association d’une éolienne, d’une unité de production décentralisée prévisible et de systèmes de stockage est considérée pour la production d’électricité dans un réseau de faible puissance de type isolé. Les performances de ce superviseur sont illustrées à l’aide de simulations et d’indicateurs quantitatifs. Finalement, la méthodologie est appliquée à différentes topologies de systèmes multisources afin d’illustrer le caractère systématique et modulaire de l’approche.

Parmi les éléments essentiels qui constitueront l’axe de transmission de puissance de l’avion plus électrique, seront présents des réseaux électriques locaux de type continu (DC). Ces systèmes, qui seront conçus de façon à permettre la récupération de l’énergie, devront comporter des systèmes de stockage et de dissipation de l’énergie électrique, afin de satisfaire, entre autres, aux contraintes de maintien de la tension du bus continu, mais aussi d’efficacité énergétique. Afin de réaliser la gestion énergétique du système interconnecté composé de la source d’énergie, des charges, du système de stockage et du système de dissipation, quatre stratégies sont proposées dans cet article, dont les objectifs sont de maintenir la tension aux bornes du bus continu et d’améliorer l’efficacité énergétique du réseau local. Elles sont comparées au travers d’indicateurs en termes de performance de maintien de tension, et d’efficacité énergétique. L’étude est réalisée sans considération de technologie de stockage particulière. La comparaison de différentes stratégies de supervision est réalisée avec deux dynamiques et deux puissances différentes des dispositifs de stockage.

With the more and more stringent energy crises and greenhouse effect, “more electric” transports are considered to be one of the solutions. The More Electric Aircraft and Hybrid Electric Vehicle are the representation of “more electric” transports. Some aspect of these two means of transport as installed capacity, role of electricity, electric sources, energy storage techniques and main electrical loads are compared in this paper. The future trend of “electric” transport is also presented.

Le problème majeur induit par l’intégration en grand nombre d’éoliennes dans les réseaux est dû à leur source primaire difficilement prévisible et très fluctuante qui rend difficile leur participation aux services système (réglage de la tension et de la fréquence, black start, fonctionnement en îloté,…). L’augmentation du taux de pénétration des éoliennes sera donc conditionnée par leur participation à ces différents services, ce qui nécessitera de leur associer des systèmes de stockage de l’énergie électrique. Dans cet article, après une brève synthèse des techniques de stockage de l’énergie adaptées aux réseaux électriques, trois exemples d’étude montrant l’intérêt d’associer du stockage inertiel à des éoliennes sont présentés. Il s’agit d’un couplage éolien-diesel, d’un émulateur temps réel d’une éolienne à vitesse variable associé à du stockage inertiel et de la participation aux services système d’une petite ferme d’éoliennes à vitesse variable intégrant du stockage. Différents apports du stockage sont illustrés par des simulations numériques ou des essais expérimentaux : le lissage de puissance, le réglage de la fréquence et de la tension et l’îlotage.

La conversion d’énergie éolienne en énergie électrique peut être réalisée par divers types de machines. A l’origine, c’était la génératrice asynchrone classique, sans convertisseur électronique de puissance associé, qui était la plus largement répandue. Cependant, l’évolution technologique des convertisseurs a progressivement permis de se tourner vers des dispositifs plus complexes, réalisant, par exemple, une maximisation de la puissance convertie en fonction de la vitesse du vent, ce que n’autorise pas la machine asynchrone à vitesse fixe. Dans cet article, différentes structures d’éoliennes à vitesse variable sont brièvement présentées et l’une d’entre elles, utilisant une Machine Asynchrone à Double Alimentation (MADA), est étudiée plus en détails. Son principe de fonctionnement et ses caractéristiques essentielles sont décrits et illustrés à l’aide d’enregistrements et relevés expérimentaux de longue durée (plusieurs heures) réalisés sur une machine de 1,5 MW. Les différentes zones de fonctionnement – combinaisons de vitesse du vent, vitesse de rotation de la machine et puissance électrique produite - sont clairement mises en évidence ainsi que les principales caractéristiques de réglage. Un modèle mathématique est ensuite proposé, intégrant les divers dispositifs de commande de la génératrice dans ses quatre zones de fonctionnement. Il s’agit d’un modèle continu équivalent, reposant sur la modélisation de la machine dans un référentiel de Park. Les paramètres du modèle sont dérivés des caractéristiques générales du système et des résultats des mesures sur l’éolienne réelle. On montre enfin l’intérêt d’un tel modèle, dans le contexte particulier de l’évaluation des interactions entre l’éolienne et le réseau de distribution MT auquel elle est raccordée (par exemple, les variations du plan de tension ou l’influence sur les mécanismes de protection).

La pénétration des sources de production décentralisée dans les réseaux électriques est une problématique majeure : accroître leur capacité à participer aux services système, déterminer leur zone d’influence selon leur point de connexion au réseau, autant de travaux à mener afin d’accroître le taux de pénétration de ces sources dans les réseaux électriques futurs. Le développement de plates-formes expérimentales est indispensable à la validation de nombre de ces travaux. Nous présentons dans cet article un banc d’essai en phase de développement, dont le rôle est d’émuler un système de génération éolienne à vitesse variable, associé à un stockage d’énergie sous forme inertielle. Nous y développons les différentes parties, et validons chacune d’entre elles par des relevés expérimentaux.

The challenges raised by new energy technologies, clean energy sources and energy efficiency led us to reconsider the way we manage energy in electricity grids and the way the stakeholders are involved. To tackle these issues, the focus should emphasize not solely the technical side, but also the sociological and economic issues related to the development of these new energy solutions. This paper presents an Energy Management System (EMS) addressing the following question: how to take into account, from the grid point of view, a stakeholder willing to be involved in the grid ? Involvement-profiles amongst stakeholders, particularly the households, in terms of electricity consumption/production can be defined by a socio-economic approach, and we chose to use a potential game approach from the game theory to integrate those profiles and imagine the possible interactions among them, incorporating their sensitivities and objectives.

The regenerative braking is an efficient way to save energy in DC railway power networks. SNCF led some investigations on the regenerative braking covered by a DC substation called Massena. These investigations point out that up to 36% of the power generated during braking was burnt in mechanical brakes. To stop this waste, SNCF decided to set up a reversible power electronic converter on Massena DC substation in order to flow the regenerative electricity for other possible use. To estimate roughly the possible energetic savings with this new inverter, simulations of the electrical railway network with the inverter modeled as a storage system were made. They show that the power sent to the reversible converter can reach up to 2.2 MW and 1.5 GWh of annual energetic saving. Also, the introduction of the controllable converter has initiated a new possibility in the future development of the railway network: its conversion into a railway smart grid. The architectures for this new option were established by considering the adding of new stakeholders especially renewable energy generation and storage systems.

Energy storages are emerging as a predominant sector for renewable energy applications. This work concerns a photovoltaic system that combines two storage technologies (one for energy needs NCA batteries and another for power SuperCaps Maxwell). A smart supervision algorithm based on fuzzy logic has been successfully developed. Simulations show that it achieves the desired objectives in terms of compliance with production program while respecting the various constraints of electric grid manager (power smoothing, frequency regulation, etc.). In addition, a comparative study of different storage configurations especially in terms of storage components lifspan and system Levelized Cost of Energy (LCOE) has been carried out. A life cycle cost analysis has been made to help designers in their choice. Results shows that: to have a good frequency adjustment with respect of the production program and with a reasonable storage total cost, a power storage ≥ 50% installed PV power must be used. A ratio of one is recommended. In addition, the studied system have a LCOE below 250 €/MWh.

In this study, the load profile estimation is done using the profiling technic, and its performance is enhanced using the real consumption values of the consumers. The results of estimation are evaluated using the measured data at the level of HV/MV (High Voltage/Low Voltage) substation and also MV feeders containing industrial and residential consumers and wind power productions. Based on the gap between actual measured data and estimated profiles, a correction factor is introduced that is applicable at the level of single MV/LV substations. These factors will be used for grid simulation and planning studies where the results will be more reliable compared to the previous estimation technics.

This paper proposes a V2G charging scheduling scheme for energy invoice minimization of railway station parking lots hosting plug-in electric vehicles. Using a two layer optimization technique the daily load profile of the railway station is reduced in order to increase the load factor and minimizing the annual energy invoice (AEI) of the station. Binary linear programming is used as second layer for charging/discharging scheduling problem. The final results shows interests of using the proposed approach conducting its impact on minimizing annual optimum subscribed power, maximum demand power and annual energy invoice.

In this paper, a photovoltaic system with hybrid storage connected to the grid has been studied. A smart supervision algorithm based on fuzzy logic has been successfully developed. In addition, a comparative study of different hybrid storage possibilities in terms of batteries longevity has been done using rain-flow cumulative damage method.

In this paper, a photovoltaic system with super capacitors and batteries hybrid storage connected to the grid has been studied. A smart supervision algorithm based on fuzzy logic has been successfully developed. In addition, contribution of storage hybridization on batteries longevity has been proved using rain-flow cumulative damage method.

This paper presents the contribution of electric vehicles to the distribution grid and railway station parking lots and their uncontrolled charging impacts on these grids. The economic indicators have been chosen as performance criteria. The benefits and advantages of using the charging/discharging coordination in term of economic indicators have been evaluated by using mixed integer linear programming and interior point for nonlinear optimization. The impacts of different charging scenarios have been evaluated and the results show high interests of using coordination charging techniques and V2G technology for grid service providing.

In this paper, a traffic-based modeling for electric vehicle charging profile is proposed. An optimization process will find the best-fitted probability distribution function to the real traffic data. The impacts of electric vehicles charging profile on the regional distribution network, and a typical railway station, proposing EVs parking lots facilities, are discussed. The results show a significant increment of annual energy purchase price for the downstream consumers that would be possibly reduced by proposing supervision system aimed to charging coordination.

This paper explores the feasibility of electric vehicle contribution to the grid ancillary services. Thanks to a probabilistic approach, the technical possibilities of Vehicle-to-grid ancillary services are assessed. Different scenarios with respect to the number of EVs fleet and commuting behavior have been generated to assess the possibility of grid service support in sense of power, energy and appropriate time interval. Each scenario is dedicated to proper ancillary service, where the economic interest for each service has been discussed.

This paper focuses on modeling and simulation of a buck converter based on a PV standalone system. This advanced synthetic study includes PV generator modeling with parameters identification, an improved P&O (Perturb and Observe) algorithm with adaptive increment step and a detailed approach of DC-DC converter modeling. A thorough method is used to determine parameters for PI current controller. The set was used to simulate a whole photovoltaic conversion chain under Matlab/Simulink environment. A special focus has been dedicated to the influence of solar irradiation variations on converter dynamic and behavior as a range of PV current 0-8 A was considered. Simulation results confirm stability, accuracy and speed response of synthesized regulator and MPPT algorithm employed. Dynamic analyses show that the more restricting control concerns low values of current Ipv (low irradiation). This work will be useful for PhD students and researchers who need an effective and straightforward way to model and simulate photovoltaic systems.

With the increased use of wind energy the power generation several Transmission System Operators (TSO) have increasing difficulties for congestion forecasting due to the unpredictable nature of the energy source. This paper proposes to enhance the congestion management using a real time supervisor. This supervisor is developed to perform automatic and dynamic re-dispatching using both wind and conventional generators. In order to reduce the production constraints to the minimum, the real time congestion management is based on an indicator of the efficiency of a re-dispatching on the power flowing in the overloaded line. This approach leads to reduced re-dispatching costs and increased network reliability. The simulation of the supervisor and the test grid is realized using by the EUROSTAG. It is shown that the real-time supervisor allows maximization of renewable production during congestions while ensuring network reliability.

With the increased use of wind energy for the power generation several TSO have increasing difficulties for congestion forecasting due to the unpredictable nature of the energy source. An actual method used to deal with days-ahead congestion planning is based on an order of disconnection of the generation of the type “last generation installed, first generation limited”. This paper proposes to enhance the congestion management using a real time supervisor. This supervisor is developed to perform automatic and dynamic re-dispatching using both wind and conventional generators. In order to reduce the production constraints to the minimum, the real time congestion management is based on an indicator of the efficiency of a re-dispatching on the power flowing in the overloaded line. This approach leads to reduced re-dispatching costs and increased network reliability. Actual and proposed methods are compared in the paper using Matlab/Simulink simulations of a realistic test grid. It is shown that the real-time supervisor allows maximization of renewable production during congestions while ensuring network reliability.

To maintain a power reserve to contribute to the primary frequency control with a variable speed wind generator, two control strategies are proposed in this paper: a torque control strategy and a fuzzy logic based multivariable control strategy. The first and most simple strategy allows to maintain a regular reserve only when the WTG works at full load and needs the determination of a power reference value a priori or by the network manager. The second control strategy allows to overcome these limits without any wind speed measurement. The main result of this paper is to shown that it is possible to maintain a regular reserve whatever the wind speed. This reserve is still more regular when considering a wind farm owing to the wind speed dispersion. The performance of the proposed primary frequency control strategies is shown with the help of simulations by considering a wind farm including three wind generators.

The electricity market liberalization and the development of the decentralized production induce many new scientific and technical problems. The major problem experienced with decentralized energy sources, and particularly renewable energy ones, is that they do not usually contribute to the power network management. Their rate of penetration is then limited (to 30 % of the consumption for instance according to some experience feedback) in order to be able to guarantee the network stability under acceptable conditions. Among these sources, wind energy is expected to grow quickly in Europe during the coming years. Increasing its rate of penetration will be thus possible if this type of source takes part in the ancillary services, and can work in islanding mode. To reach these objectives with wind generators, we consider a Variable Speed Wind Turbine (VSWT) coupled to a Permanent Magnet Synchronous Generator (PMSG) combined to an energy storage system. Due to important fluctuations of the wind generator power, conventional electrochemical batteries are not adapted. We consider then a Flywheel Energy Storage System (FESS. Owing to the use of power electronics, the generator and the storage system are electrically coupled via a DC link. To evaluate the possibility of the proposed generating system (GS) to participate to the ancillary services, we consider in this paper the connection of a wind farm including three generating systems with a network including passive loads and a power grid. Generating systems are working as voltage sources with the help of a frequency droop. It is shown in this paper, with the help of simulations, that the power generated by each generating system can be controlled by fixing the power set point when they are connected to the grid. It is also shown in case of islanding, that they can share the global load of the isolated network like Uninterruptible Power Supply (UPS) parallel connection. This paper focus particularly on the system behaviour working in islanding mode when load varies.

The aim of this paper is to propose a control strategy of the power exchanged between a wind generator and an AC Grid. This control is based on current resonant controllers which ensure a high dynamic and robust power control through an inverter-transformer association. Experimental results point out the efficiency of the proposed control strategy.

The flywheel energy storage systems (FESSs) are suitable for improving the quality of the electric power delivered by the wind generators and for helping these generators to contribute to the ancillary services. At the present, the FESSs containing a flux-oriented controlled induction machine (IM) are mainly considered in the technical literature for this type of application. This paper proposes the direct torque control (DTC) for an IM-based FESS intended to be associated with a variable-speed wind generator. The proposed application of the DTC involves two aspects: (i) the IM must operate in the flux-weakening region, and (ii) it must change rapidly and many times between the motoring and generating modes. The experimental results presented in this paper show that the DTC can fulfill these requirements. Another aspect treated in this paper concerns the DTC optimization in order to increase the FESS efficiency when operating at small power values.

The supply of ancillary services is now a new challenge to boost the development of Distributed Generators (DG). This paper investigates the suitability of various strategies for the AC voltage control of a grid-connected DG via a three-phase voltage-source inverter with a second-order filter.

The level of penetration increase of dispersed generation in the electrical networks is a major scientific aim: to increase the possibility to participate in the ancillary services, to determine the influence zone according to the network connection point, ...etc. The development of experimental test benches is necessary to validate theoretical studies. In this paper, we present a 3kW test bench, emulating a grid connected or stand-alone real-time variable speed wind generator emulator associated to a flywheel energy storage system.

In order to investigate the dynamic behaviour of a wind turbine with Doubly Fed Induction Generator (DFIG) connected to the network during grid disturbance, this paper presents an equivalent continuous model. This model includes mechanical, electrical parts and the connection system to a distribution network. A comparison of two different DFIG control strategies during network faults is shown with the help of numerical simulation.

The flywheel energy storage systems (FESSs) are suitable for improving the quality of the electric power delivered by the wind generators and for helping these generators to contribute to the ancillary services. At the present, the FESSs containing a flux-oriented controlled (FOC) IM or a SRM are mainly considered in the technical literature for this type of application. This paper proposes the DTC for an IM-based FESS destined to be associated with a variable-speed wind generator, and wants to show that the DTC could be more advantageous than the FOC.

In this paper, the modelling of an autonomous variable speed micro hydropower station is presented. It is composed of a doubly fed induction generator linked mechanically and electrically to a permanent magnet synchronous machine which may recover or supply the slip power and which feeds the DFIG with its magnetizing reactive power leading to classical capacitor removing. The model lies on both a classical approach, based on a Park representation, and an Energetic Macroscopic Representation (EMR). In its first part, this paper develops the modelling principles and underlines the complementarity of both approaches. The control strategy is then depicted in the case of passive loads supplying. Finally, some simulation results are showed and commented.

The flywheel energy storage systems (FESSs) are suitable for improving the quality of the electric power delivered by the wind generators and to help these generators to contribute to the ancillary services. This paper makes a comparative study of two low-speed FESSs with a classical squirrel-cage Induction Machine (IM) and a Permanent-Magnet Synchronous Machine (PMSM), respectively, in the aim of its association to a wind generator.

The dispersed generation increases into the distribution system. Until now, this generation has generally been considered as “negative loads” because it does not participate directly to the ancillary services (voltage and frequency control, islanding…). But this approach will not be acceptable in the future when the level of penetration of dispersed generation will be over 20% which will be the case in numerous countries by 2010-2020. Indeed, the network stability would be endangered which would increase the risk of black-out. It is then necessary to evaluate the ability of the dispersed generation to participate directly to the ancillary services, which are now priced on the open market. Moreover, the dispersed generation would have to be able to continue to generate in case of network failures like a voltage sag or an islanding. The dispersed generation would then have to be able to work without auxiliary source, ensures the generation-consumption balance, set the adequate frequency, the amplitude of the voltage wave, enhance the network safety and reliability. To reach these objectives with wind generation, we consider a Variable Speed Wind Turbine (VSWT) coupled to a Permanent Magnet Synchronous Generator (PMSG) combined to an energy storage system. Due to important fluctuations of the wind generator power, conventional electrochemical batteries are not adapted. We consider then a Flywheel Energy Storage System (FESS). Owing to the use of power electronics, the generator and the storage system are electrically coupled via a DC link. To evaluate the possibility of the proposed generating system (GS) to participate to the ancillary services, we consider in this paper the interconnection of two of them with a network including passive loads and a power grid. Generating systems are working as voltage sources with the help of a frequency droop. It is shown in this paper, with the help of simulations, that the power generated by each generating system can be controlled by fixing the power set point when they are connected to the grid. It is also shown in case of islanding, that they can share the global load of the isolated network like Uninterruptible Power Supply (UPS) parallel connection. Finally, it is shown that the proposed generating system is able to continue to generate power during an unbalanced 600ms voltage sag of 20%. It may be noticed that electrical quantities in the network connection of the generating system are controlled with the help of resonant controllers.

In this paper, a brief review of small hydropower situation and classical technologies, implying fixed speed operation, is achieved in a first part. Subsequently, a variable speed micro hydropower station is presented. It is composed of a doubly fed induction generator linked mechanically and electrically to a permanent magnet synchronous machine which may recover or supply the slip power and which feeds the DFIG with its magnetizing reactive power leading to classical capacitor removing. These features allow the station to be autonomous which is interesting in the case of isolated loads supplying. Simulations are carried out at different operating points.

A high power Wind Energy Conversion System (WECS) connected to isolated loads is considered in this paper. As the WECS must work without auxiliary source, ensure the balance generation – consumption, set the adequate frequency and voltage, it is combined to a Flywheel Energy Storage System (FESS). For the WECS, we have considered a Variable Speed Wind Turbine (VSWT) coupled to a Permanent Magnet Synchronous Generator (PMSG). A control strategy of this system is proposed. As loads are not necessary balanced, it is proposed to control directly the alternating line-toline voltage of the network with the help of resonant controllers. The performance of the proposed global system is analyzed with the help of simulations.

Parmi les sources à énergies renouvelables, l’hydroélectricité est actuellement la plus développée dans le Monde de par notamment l’existence des centrales de forte puissance regroupées sous le vocable de "grand hydraulique". Les sites de construction de nouveaux grands aménagements se font désormais rares. En revanche, l’intérêt pour les énergies renouvelables et la production décentralisée croissant, la "petite hydraulique" possède un fort potentiel de développement. Cet article se propose de réaliser un état de l’art concernant les petites centrales hydroélectriques, de modéliser et de simuler une structure de micro centrale autonome à vitesse variable basée sur la mise en cascade d’une machine asynchrone à double alimentation et d’une machine synchrone à aimants permanents ; ce groupe possédant la particularité de présenter un couplage à la fois électrique et mécanique.

Le développement de la production éolienne permet de satisfaire les objectifs de lutte contre le réchauffement climatique. Mais, dans certaines zones du réseau électrique, l’intégration d’un volume important de production peut créer des congestions. Tout d’abord, cet article évalue la méthode actuellement mise en œuvre pour se prémunir des congestions dans le réseau électrique. Ensuite, une méthode de gestion des congestions permettant de minimiser les contraintes d’exploitation est proposée. Cette méthode, basée sur un indicateur de l’efficacité d’un re-dispatching sur la décongestion d’une ligne, peut être appliquée de façon prévisionnelle ou en temps réel. Enfin, un scénario réaliste simulé numériquement permet d’évaluer l’efficacité de la méthode proposée pour la gestion des congestions.

Le génie électrique est une discipline difficile à apprendre et à enseigner. Elle exige en effet, de la part des étudiants, un niveau d’abstraction beaucoup plus poussé que dans d’autres branches. Les technologies de l’information et de la communication peuvent dans ce contexte s’avérer des outils précieux. Dans ce but, un site internet d’e-learning en génie électrique est développé par quatre Universités et Grandes Ecoles avec le soutien de l’Union Européenne. Cet article présente ce projet, brièvement quelques réalisations, les premiers résultats de l’évaluation de l’impact de ce nouvel outil auprès des étudiants et la création d’une association sans but lucratif ayant pour objectifs de poursuivre l’expérience et élargir le partenariat.

Parmi les sources à énergies renouvelables, l’hydroélectricité est actuellement la plus développée dans le Monde de par notamment l’existence des centrales de forte puissance regroupées sous le vocable de "grand hydraulique". Les sites de construction de nouveaux grands aménagements se font désormais rares. En revanche, l’intérêt pour les énergies renouvelables et la production décentralisée croissant, la "petite hydraulique" possède un fort potentiel de développement. Cet article se propose de réaliser un état de l’art concernant les petites centrales hydroélectriques, de modéliser et de simuler une structure de micro centrale autonome à vitesse variable basée sur la mise en cascade d’une machine asynchrone à double alimentation et d’une machine synchrone à aimants permanents, ce groupe possédant la particularité de présenter un couplage à la fois électrique et mécanique.

Le développement récent de la production décentralisée d’électricité est un phénomène qui touche tous les pays industrialisés, même si l’ampleur et la dynamique de ce mouvement peuvent différer d’un pays à l’autre. Ce papier vise à jeter les bases du contexte technique, environnemental et normatif de cette évolution.

As renewable electricity generation is increasing, several concerns are addressed by the Transmission System Operators (TSO) towards the management and the security of the electrical grid. This paper reviews solutions to ease the integration of renewable energy in the electrical systems through enhanced supervision of renewable generation as well as utilisation of short term or medium term storage system. Amount these solutions, supervision and storage allow to smooth output power, avoid congestion and participate in primary frequency control. Dynamic power system simulations are shown to illustrate the efficiency of the supervision methods.

Abstract— A dynamic model of a micro gas turbine generator is proposed in this paper. A particular graphical representation of is used to highlight the causal order of all mathematical equations. It is shown that the obtained model is interesting for developing a Matlab Simulink model and for designing the control strategy. In order to control the power flow a second model is designed to describe energy variations in the inertia and losses. Then we demonstrate that this model is sufficient to design the control system of the turbine. The control system is then simulated with the help of Matlab-Simulink™, by considering a 30 kW turbine.

Small size hydro plants are commonly constituted of fixed speed drives. To allow extended control features for these sources in order to integrate them into the energy grid, an autonomous variable speed doubly fed induction generator (DFIG) based source is proposed. Modelling process of the DFIG is described ; it leads to an unified control strategy for operation on a power grid or isolated loads. Transition from grid connected mode to isolated one is discussed.

Abstract - In this paper an equivalent continuous model of power electronic converters is used to design a dynamic model of an entire gas micro turbine generation system. It is shown that the obtained model is interesting for analyzing the dynamic behavior of the entire system and for designing the control strategy of ac and dc electrical quantities. In order to control the power flows a dedicated model is designed to describe energy variations in storage elements (inertia, DC capacitor bus) and various losses. Then we demonstrate that this model is sufficient to design the control system of the entire power generation system, meanwhile the turbine, the permanent synchronous generator and the grid connected converter. The proposed global model is simulated with the help of Matlab-Simulink™, by considering a 30 kW Micro Turbine Generator.

Les enjeux énergétiques et environnementaux sont à l’origine d’une forte croissance de la production d’électricité à partir d’énergies renouvelables depuis le début du XXIème siècle. Le concept de développement durable et le souci des générations futures nous interpellent au quotidien permettant l’émergence de nouvelles technologies de production d’énergie, et de nouveaux comportements d’utilisation de ces énergies. L’émergence rapide de nouvelles technologies peut rendre la compréhension et donc la perception de celle-ci difficile. Ce livre a pour but de contribuer à une meilleure connaissance de ces nouvelles technologies de production d’électricité en s’adressant à un public varié. En effet, il présente les enjeux, les sources et leurs moyens de conversion en électricité suivant une approche générale et développe les notions scientifiques de base permettant d’en appréhender les principales caractéristiques techniques avec une vision d’ensemble. Les objectifs de cet ouvrage sont : - de présenter les systèmes de production d’électricité à partir de ressources énergétiques renouvelables des petites aux moyennes puissances (jusque 100 à 200 MW), - d’introduire les notions électrotechniques de base nécessaire à la compréhension des caractéristiques de fonctionnement de ces convertisseurs, - d’évoquer les contraintes et problèmes d’intégration dans les réseaux électriques de ces moyens de production, - de proposer quelques exercices pour s’autoévaluer. Contenu 1. La production d’électricité à partir d’énergie renouvelable, Benoît Robyns. 2. Le solaire photovoltaïque, Arnaud Davigny. 3. L’éolien, Bruno Francois et Benoît Robyns. 4. L’hydroélectricité terrestre et marine : houle et marées, Benoît Robyns et Antoine Henneton. 5. La production d’origine thermique, Jonathan Sprooten. 6. Problématique de l’intégration de la production décentralisée dans le réseau électrique, Benoît Robyns.

Energy and environmental issues have caused a marked increase in electricity production from renewable energy sources since the beginning of the 21st Century. The concept of sustainable development and concern for future generations challenge us every day to produce new technologies for energy production, and new patterns of use for these energies. Their rapid emergence can make the understanding and therefore the perception of these new technologies difficult. This book aims to contribute to a better understanding of the new electricity generation technologies by addressing a diverse audience. It presents the issues, sources and means of conversion into electricity using a general approach and develops scientific concepts to understand their main technical characteristics. Systems of electricity generation from renewable energy resources of small to medium powers are presented. The basic electrical concepts necessary for understanding the operating characteristics of these energy converters are introduced, and the constraints and problems of integration in the electrical networks of those means of production are discussed. Several exercises are provided to the reader for evaluation purposes. Contents 1. Decentralized Electricity Production from Renewable Energy, Benoît Robyns. 2. Solar Photovoltaic Power, Arnaud Davigny. 3. Wind Power, Bruno Francois and Benoît Robyns. 4. Terrestrial and Marine Hydroelectricity: Waves and Tides, Benoît Robyns and Antoine Henneton. 5. Thermal Power Generation, Jonathan Sprooten. 6. Integration of the Decentralized Production into the Electrical Network, Benoît Robyns.

Les technologies modernes de stockage de l’énergie électrique sont un élément clé du développement durable ; elles permettent désormais d’envisager le déploiement de véhicules électriques aux performances acceptables et une électrification croissante de certains systèmes de transport tels que les aéronefs. Cet ouvrage met en évidence l’importance du stockage de l’énergie électrique dans un contexte de déploiement de réseaux électriques intelligents appelé « smart-grids ». Ces réseaux interagissent de façon croissante avec certains systèmes de transports tels que les véhicules électriques et hybrides rechargeables, les trains, métros, trams et bus électriques. Dans une démarche pédagogique, cet ouvrage présente les outils méthodologiques permettant de construire un système de gestion énergétique du stockage. Ces outils basés sur de l’intelligence artificielle et des techniques d’optimisation explicite sont analysés à travers des études de cas concrets : les réseaux embarqués en aéronautique, l’intégration des véhicules électriques dans le réseau électrique, les véhicules hybrides ou encore la traction ferroviaire hybride et ses installations. Table des matières 1. Problématique du stockage de l’énergie électrique dans les systèmes de transport. 2. Réseaux local continu à échanges d’énergie embarqués en aéronautique. 3. Véhicules électriques et hybrides. 4. Système ferroviaire : chaîne de traction diesel électrique hybride. 5. Système ferroviaire : installation fixe de traction électrique hybride.

To enable the sustainable development of complex modern transportation systems, the storage of electrical energy is crucial. This is particularly true given the rapid developments made for electric transportation services in smart cities, and the demand for interaction between different transport systems. This book presents tools to design such an energy management system, following a generic approach; this includes the deployment of smart electric power grids, services for the storage of electrical energy, and the use of artificial intelligence and explicit optimization methods. The use of these methods is explored through various case studies: more efficient electrification of aircraft, the development of hybrid autonomous vehicles and locomotives, and more efficient integration of road and railway transports in the electrical grid. In combining industrial theory and practice, this book will appeal as a reference to engineers and researchers working in the field of electrical energy management.

The storage of electrical energy is a long-standing issue that has been only very partially resolved to date, particularly from an economic perspective. The development of renewable energies and the need for means of transport with reduced CO2 emissions have generated new interest in storage, which has become a key component of sustainable development. The aim of this book is to contribute to the better understanding of both existing storage technologies and those that are under development, particularly with regard to their management and economic enhancement. Across seven chapters, the authors highlight the importance of storing electrical energy in the context of sustainable development in "Smart Grids". They discuss the variety of services that storing electrical energy can provide and support. Methodological tools are provided following a generic approach based on artificial intelligence, among other. They are presented throughout the book and discussed alongside concrete case studies to provide practical examples of their possible applications.

Le stockage de l'énergie électrique est un problème déjà ancien qui n'a été résolu que très partiellement jusqu'à présent, en particulier du point de vue économique. L’électricité est principalement produite en flux tendu à partir de moyens flexibles (hydraulique et thermique sur la base de combustibles non renouvelables). Le développement des énergies renouvelables et le besoin de moyens de transport décarbonnés donne un nouvel intérêt pour le stockage qui devient un élément clé du développement durable. Ce livre a pour but de contribuer à une meilleure connaissance des technologies de stockage anciennes ou en développement, et tout particulièrement sur leur gestion et leur valorisation. Les objectifs de cet ouvrage sont : – Mettre en évidence l’importance du stockage de l’énergie électrique dans le contexte du développement durable dans les réseaux électriques intelligents ou «smart grids». – Montrer les multiples services que le stockage de l’énergie électrique peut apporter. – Présenter des outils méthodologiques permettant de construire un système de gestion énergétique du stockage suivant une approche générique et pédagogique. Ces outils, basés en partie sur de l’intelligence artificielle, sont présentés au fil de l’ouvrage en lien avec des cas d’étude concrets. – Illustrer ces approches méthodologiques par de nombreux exemples concrets et pédagogiques concernant l’intégration des énergies renou-velables dans les réseaux électriques.

After a brief introduction to the main law of physics and fundamental concepts inherent in electromechanical conversion, Vector Control of Induction Machines introduces the standard mathematical models for induction machines – whichever rotor technology is used – as well as several squirrel-cage induction machine vector-control strategies. The use of causal ordering graphs allows systematization of the design stage, as well as standardization of the structure of control devices. Vector Control of Induction Machines suggests a unique approach aimed at reducing parameter sensitivity for vector controls based on a theoretical analysis of this sensitivity. This analysis naturally leads to the introduction of control strategies that are based on the combination of different controls with different robustness properties, through the use of fuzzy logic supervisors. Numerous applications and experiments confirm the validity of this simple solution, which is both reproducible and applicable to other complex systems. Vector Control of Induction Machines is written for researchers and postgraduate students in electrical engineering and motor drive design. Keywords : Efficient Power Operation - Fuzzy Logic Control - Induction Machine - Parameter Sensitivity - Vector Control Table of contents Concepts for Electromechanical Conversion.- Dynamic Modeling of Induction Machines.- Vector Control of the Induction Machine.- Theoretical Study of the Parametric Sensitivity.- Fuzzy Supervisor.- Applications. Comments : Readers will not only enjoy a new study on vector control but they will also be introduced to useful concepts and tools that are often disregarded: the control through model inversion; the necessary variable estimation; the entanglement of the control and the estimation of nonlinear systems; the sensitivity theory; robustness and desensitization and finally, the good use of fuzzy logic as an optimization method for nonlinear systems. Jean-Paul Louis, Professor at the E.N.S (French higher education school) of Cachan Francis Labrique, Professor at the Université Catholique of Louvain

Dans beaucoup d’applications à vitesse variable la machine asynchrone tend à se substi-tuer à la machine à courant continu. Cette évolution, motivée par d’indénia-bles qualités de robustesse et de fiabilité, est permise grâce aux convertis-seurs de puissance et d’électronique de commande. Toutefois, un problème majeur demeure : le modèle de Park classique de la machine, indispensable à la conception de son dispositif de commande, dépend de paramètres variants fortement suivant les conditions de fonctionnement de la machine. Après des rappels sur les principales lois physiques et concepts fonda-mentaux propres à la conversion électromécanique, les modèles mathémati-ques classiques de la machine asynchrone quelle que soit la technologie du rotor et différentes stratégies de commande vectorielles de la machine asyn-chrone à cage sont présentés. L’utilisation du formalisme des Graphes In-formationnels Causaux (G.I.C) permet de systématiser la démarche de conception et d’uniformiser la structure d’un dispositif de commande. L’ouvrage propose ensuite une approche originale permettant de réduire la sensibilité paramétrique des commandes vectorielles basées sur une ana-lyse théorique de cette sensibilité. Cette étude amène naturellement à propo-ser des stratégies de contrôle basées sur la combinaison de différentes com-mandes ayant des propriétés de robustesse différentes, à l’aide de superviseurs à logique floue. Des applications et de nombreux résultats expé-rimentaux viennent confirmer le bien-fondé de cette solution simple, repro-ductible et applicable à d’autres systèmes complexes.