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The energy transition requires rethinking how we produce and consume energy. Energy communities (EC) provide a recent legal framework for sharing energy, aiming to reduce energy bills and the environmental footprint of their participants. One of the challenges is adapting economic models to this technological upheaval. In this context, cooperative games, based on game theory, are valuable tools for modeling energy management through cooperation. However, despite their promising characteristics, cooperative games are limited by their computational complexity. The required computation time to solve cooperative games increases exponentially with the number of participants, restricting their application in energy management. This paper aims to propose a solution to apply cooperative game theory tools to larger communities using a multidisciplinary approach. For this purpose, a game subdivision approach based on the specific properties of energy communities is proposed. This methodology will be shown to be efficient in terms of computation time. While the game theory concepts are depreciated by limiting computing time, the sub-games method can become an interesting tool in energy management. Advantages and drawbacks in terms of energy management and game theory are discussed in this paper.

Climate change is requiring changes in energy use. The integration of renewable energy sources into the energy mix is a viable solution for electricity generation, but their intermittence forces us to imagine new ways to consume and distribute electricity. Thus, new economic models and new organizations have to be established. Energy communities are a recent legal solution to share renewable energy among local actors. These structures facilitate the set-up of collective self-consumption operations. Collective self-consumption is an interesting tool to increase local renewable energy consumption and limit energy losses on the distribution grid. Consequently, energy communities are pursuing a dual objective: reducing energy bills and the environmental footprint of the participants. However, the distribution of gains generated through collective self-consumption is one of the main obstacles to the implementation of energy communities. An interesting possibility comes from game theory, especially from cooperative games, as solutions concepts already exist to solve this kind of problem. In this paper, a payoff distribution is proposed through a collaborative game. The aim of the study is to explore ways to distribute gains generated by collective self consumptions on individual self consumptions. These gains are 8% on the total energy bill and 25% on the self-consumption rate, assuming a collective objective based on the self-consumption rate and individual objectives based on the price of energy. In order to distribute the financial gains, two major concepts in cooperative game theory are studied in this paper: the Shapley Value and the Nucleolus. The advantages and drawbacks of these concepts in an energy community context are identified, as these concepts are based on two different philosophies: The properties of individual fairness of the Shapley Value and collective fairness of the Nucleolus for energy management are therefore discussed. Furthermore, a methodology is proposed to enable a fairer distribution of payoffs according to specific energy management parameters, such as efficiency and flexibility.

The opening up of the railway to competition in Europe has been accompanied by many technical challenges never before seen in the railway field. One of these challenges concerns precise energy metering. As European railways have been a monopoly until now, the current systems can only measure the energy consumption of a single operator. In accordance with European law, the installation of an energy meter has been mandatory in new or refurbished rolling stocks since 2014. Nevertheless, these energy meters are still not fully reliable, with misreadings and missing readings being common occurrences. To address the problem of energy metering data reliability, this paper presents a method for validating the reading measurement based on a physical model and validates it in two different case studies. For the issue of energy metering data availability, different estimators are developed, and their performance are shown with the aim of calculating the missing consumptions for both case studies. Finally, the paper suggests how these methods may be implemented in other types of trains.

To face environmental issues, SNCF, the French railway, has chosen to improve the energy efficiency of its electrical power system by investigating solutions for regenerative braking. With the contribution of Railenium, a research and test center in railway activities, they aim to recover the braking energy by setting up a reversible inverter in a DC substation “Masséna”. The issue is to test, implement and compare various control solutions to increase the energy efficiency with minimum impacts on the railway operation. In this paper, a simulation model for studying a reversible power substation is addressed by considering AC and DC equivalent electrical sources. The proposed model provides a reliable tool for analyzing the behavior of the railway electrical network during specially braking mode. In order to validate this model, its simulation results are compared with the ones obtained from Esmeralda, the SNCF professional software. A first configuration is led without the inverter and gives certified Esmeralda results and validates the proposed model despite some gaps in powers and voltages due to differences in input data and models. A second comparison with inverter is presented to highlight the main difference between the proposed model and Esmeralda. In addition, laboratory experimental activities are put forward to investigate the proposed model by using power-hardware-in-the-loop simulations. Finally, a simulation test under MATLAB software with fifty train’s traffic is presented to estimate the energy saving thanks to the installed inverter. For this latter case study, the system sent back to the national AC grid around 6.9% of the total energy consumed by all trains.

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.

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.

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.

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.

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 direct modulation strategy of a three-level inverter with self stabilization of the DC link voltage is extended to a five-level inverter. Therefore, a new modeling and control strategy of a five-level three-phase Diode Clamped Inverter (DCI) is presented. The obtained modeling shows that modulated multilevel voltages are obtained by combination of eight different three-level functions, which are called modulation functions. Therefore, a space vector scheme without using a Park transform is explained. Based on this algorithm, the location of the reference voltage vector can be easily determined. Then, the voltage vectors are selected to generate corresponding levels and simultaneously their durations are calculated. More over, the redundancies of different switch configurations for the generation of intermediate voltages are used to limit the deviation of capacitor voltages. Simulation results for a five-level three-phase Diode Clamped Inverter are presented to show the good performance of the proposed balancing modulation.

In this paper, a simple direct modulation strategy that enables to copy directly modulated waveforms onto output voltages of a five-level three-phase inverter is presented. The obtained modelling shows that the modulated multilevel voltage is obtained by combination of eight different three-level functions, which are called modulation functions. Therefore, a space vector modulation without using a Park transform is explained. Based on this algorithm, the location of the reference voltage vector can be easily determined. Then, the voltage vectors are selected to generate corresponding levels and simultaneously their durations are calculated. Simulation results for a three-level and five-level three-phase inverters are presented to verify the performance of the proposed space vector modulation.

This paper presents a simple and general direct modulation strategy that enables to copy directly modulated waveforms onto output voltages of a multilevel three-phase Diode Clamped Inverter (DCI). A general modelling of this converter is presented. A space vector scheme is developed without using Park transforms. Based on this algorithm, the location of the reference voltage vector is determined and the voltage vectors for the modulation are deduced. Simultaneously, their durations are calculated. The proposed algorithm is general and can be directly applied to a (n+1) levels inverter independently on its topology (Diode Clamped Inverter, Neutral Point Clamped, Flying Capacitor Inverter...). To verify this algorithm, both control algorithms of a 5-level DCI and a 11-level DCI are considered and simulation results are given.

A novel concept of application of Artificial Neural Networks (ANN) for generating the optimum switching functions for the voltage and harmonic control of DC-to-AC bridge inverters is presented. In many research, the neural network is trained off line using the desired switching angles given by the classic harmonic elimination strategy to any value of the modulation index. This limits the utilisability and the precision in other modulation index values. In order to avoid this problem, a new training algorithm is developed without using the desired switching angles but it uses the desired solution of the elimination harmonic equation, i.e. first harmonics are equal to zero. Theoretical analysis of the proposed solving algorithm with neural networks is provided, and simulation results are given to show the high performance and technical advantages of the developed modulator.

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.

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 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.

To resolve the global problem of Climate change is one of the most important occupations goals for most countries in the world. Many solutions are proposed such as Sustainable Development including energy transition. Among the new and developing practices, we find individual and collective self-consumption. The individual as a participant in this type of operation must have an awareness of this policy through several actions such as education and training on the one hand and the implementation of information measures to the public from children to young people to adults, in the other hand. However, the question that arises is: “do the actors or the energy consumers know these different actions of energy management and environmental protection?” Therefore, this paper aims to investigate the level of awareness among individuals regarding collective self-consumption policies. Based on a new method of energy sharing using a collaborative game, this paper studies the acceptability of this system of sharing by actors using data analysis. Through this survey, we propose a synthesis of the answers of different topics treated throughout the questionnaire such as: background information, awareness and acceptability of the proposed energy sharing method. Therefore, we closely determine the different profiles of prosumers to better guide energy control strategies considering consumer behavior. Our study targets students and staff in the university community to integrate sustainable development especially climate change action into their daily behavior by studying their awareness. Through a survey the behavior of individuals is studied, and their opinions about the system of energy sharing considered. Keywords: Collective self-consumption, survey, data analysis, awareness, university community

While integrating renewable energy sources into the energy mix is effective in mitigating climate change, their intermittent nature requires new ideas on how to use and distribute electricity. It is therefore necessary to imagine new organizations and economic models. With an engineering approach, demand-side management becomes crucial to address the constraints on the distribution grid. Optimal energy behaviors are in, this context, often regulated by the price. Moreover, new economic models based on market logic are directed by the deregulation of the energy markets. A more recent legal way for local actors to exchange renewable energy is through energy communities often combined with collective self-consumption. They open a new approach to energy management based on ressource pooling and cooperation among consumers. This work proposes to explore a new methodology of demand-side management based on a cooperative game. It will be proved that a collective objective based on prioritizing local energy production in community consumptions can lead to individual costs and environmental impact reduction. The work integrates several motivations of stakeholders in their participation in a collective self-consumption operation. A new methodology based on the LCA method is deployed to assess environmental impacts. Ethical distributions of gains based on game theory will also be discussed. Several game-theoretic concepts are explored, opening up philosophical questions such as: Should we reward those who participate the most, but who are also often the wealthiest? Should we encourage the most vulnerable? From a technical point of view, other questions are discussed, such as: Which behaviors should be rewarded in the context of energy management? Should energysaving behavior be rewarded? Should flexibility be rewarded? The aim of this paper is to propose a novel energy management system able to meet the environmental and social challenges of the energy transition.

This paper presents a DC-bus signaling (DBS) control method for a smart grid with a PV plant and multiple electric vehicle charging stations (EVCS). The proposed DBS method aims to maximize self-consumption and reduce greenhouse gases (GHG) intensity of the EVCS.The proposed DBS system uses the DC bus voltage as a signal to modulate the EVs charging power, to adapt to PV production in real-time. Therefore, the need for a communication infrastructure is minimized, thus increasing the system’s robustness. Moreover, a minimal charging power is set to still be able to provide a charging service in the case of a low PV production.Real-world data from the smart grid demonstrator at the Catholic University of Lille in northern France are used for PV production and EV consumption. The system is modelled using MATLAB/Simulink and simulated to be compared with actual data from a chosen day. The simulations results show that the DBS control system allows an increase in the self-consumption and lower GHG emissions, while keeping a satisfactory charging service.

To meet the high transport demand in the urban areas, railway companies are required to increase train traffic and particularly the feeder power that supplies the trains. Increasing DC power leads to rising fault currents in the substations that can exceed 110 kA. The main purpose of this study is to limit fault current and optimise rectifier diode (I 2 t) in the DC substation for railway networks. This limitation will enable to reduce the oversize of the network components, to minimise their investment and maintenance costs. A resistive superconducting fault current limiter is used. First, the DC substation with and without faults current is modelled using EMPTP-RV software. A detailed model of the superconducting limiter based on REBCO tapes is then modelled using Matlab software. Results from REBCO models are integrated into the substation under faults conditions and then optimised to achieve the required limitation. A case study is carried out using the SNCF network in Paris. Results show 50% faults limitation and 23.75% I 2 t optimisation of rectifier diode in transient regime.

Climate change is requiring changes in energy use. The integration of renewable energy sources into the energy mix is a viable solution for electricity generation, but their intermittence forces us to imagine new ways to consum and to distribute electricity. Thus, new economic models and new organizations have to be established. Energy communities are a recent legal solution to share renewable energy among local actors. Joining a community can allow participants to reduce their energy bill and environmental footprint. However the distribution of gains generated through collective self consumption is one of the main obstacles. An interesting possibility comes from the game theory, especially from cooperative game, as solutions concepts already exist to solve this kind of problem. In this paper, a payoff distribution is proposed through a collaborative game. Two parrallel optimizations are established in order to compare the benefits of collective self consumption to individual self consumption. It is shown that the coordination of flexible devices to maximize the collective self-consumption rate generates gains on the electricity bill and environmental footprint. The aim of the study is then to explore ways to distribute these gains. Two major concepts in cooperative game theory are studied in this paper, the Shapley Value and the Nucleolus. The advantages and drawbacks of these concepts in an energy community context will be established. A methodology is proposed to permit a fairer distribution of payoffs according to specific energy management parameters such as efficiency and flexibility.

Environmental issues are leading to rethink the way energy issues are approached. The integration of renewables energies into the energy mix is one of the long-term solutions for electricity production. Their intermittency forces utility companies to reconsider the way energy is consumed. Indeed, consumers will not remain regarding the electricity networks but will be asked to participate in the daily management of electricity. Several solutions are emerging around smart grids and demand side management, but they are mainly focused on technological solutions. Human behaviors are rarely considered in energy management algorithms. Similarly, the environmental impacts of the whole system are rarely quantified. Recently, legal incentives such as energy communities have appeared. These aim to include different actors to participate in economic operations regarding energy while reducing their environmental impacts. In this context, energy sharing, and self-consumption become at the heart of energy issues. In this paper, we propose to integrate hypotheses from the social and human sciences into an energy management of a community. Its environmental impact will also be integrated into this management through calculations of carbon emissions based on LCA methods. The gain/loss of stakeholders if they participate in a collective self-consumption operation regarding their sensibilities on energy consumptions will be discussed.

This work is focalized on the topical issue of improving the energy efficiency of train in braking mode. The improvement is explored by integration and control of a reversible inverter in a DC power substation to inject the braking power from the DC side to the AC power grid. This solution makes the substation reversible. The objective of this study is to investigate a control strategy by adjustment of the DC voltage for the inverter in order to recover the maximum of electric braking energy by keeping the DC voltage of the substation stable with a reference value. A comparative study of simulation results of the suggested control scheme with a droop control technique for the railway substation “Massena” in Paris is presented.

The opening of the railway use all around Europe carried plenty of technical challenges never seen before in the railway field. An important challenge in energy billing filed, is to precisely do the billing of the consumed energy for each railway company in a reliable way. For that, in ground applications, RTE (the French national transmission system operator, who is in charge of the energy metering in railways by law in France) normally installs two energy-meters to ensure the reliability of the measurements. Nevertheless, in agreement with the European law, the installation of only one energy-meter is mandatory in the new/refurbished rolling stock since 2014. To ensure the correct billing of the railway companies, the data collected by the energy-meters must be validated. In other cases no measure is available due to different technical problems, therefore a system that estimates the energy consumptions of those journeys is necessary. In this paper, a validated data-set is used to reconstruct the amount of energy consumed by trains whose energy-meters data is missing or not valid. The validated data will be the start point for different estimators of the consumed energy by the trains. This dataset is composed by the information collected from the energy-meters (date information and GPS position of the train) and train run data (transit times on fixed points of the line). Different types of estimators for the energy reconstruction are compared with real measurement data from a regional train circulation for a couple of years. Finally, a discussion of the performance of the different estimators will be shown.

The efficiency of a regenerative braking energy operation is discussed in this paper. Sending recovered energy back to the grid is possible using a reversible converter installed in a DC railway power substation. The strategy of such converter impacts the efficiency of the recovered energy because of coupling between the converter strategy and the regenerative braking strategy of the train. This coupling is highlighted in this paper and results on real time simulation test bench of a specific railway section in Paris are discussed.

The subject addressed in this paper concern the involvement of stakeholders in the management of the energy in a smart-grid. Demand side management (DSM) is indeed of particular interest to adjust the load, relying on the participation of stakeholders on a daily basis, or at least during peak hours. We discuss therefore a new methodology aiming to extract the flexibility of the stakeholders in a smart grid, by including their profiles and therefore there sensitivities and objectives in the optimisation process of the energy balance. The contribution of this paper is therefore twofold: Firstly, by the development of a methodology to understand and segment real consumer profiles for energy management, and secondly by studying and testing how each considered stakeholder can increase his satisfaction in a day ahead Demand Response program.

This paper proposes to optimize the real time operation of a microgrid controlled with a two-layer Model Predictive Controller supervisor. Based on the classical decomposition of control level, the proposed supervisor tracks long-term economic references from a classical economic optimization routine. The optimization problem is formulated as a Mixed Integer Quadratic Problem and uses the different power references as levers to reach this optimum and maintain the state of the microgrid within limitations. In addition, it is able to minimize the grid losses.

To address the new challenges arising from the higher penetration of renewable energy in electrical grid, Demand Side Management (DSM) and Demand Response (DR) aim to involve the residential as well as industrial consumers in the grid equilibrium. Ensuring benefits for both utility and users requires the consumers sensitivities to be understood and then included in the Energy Management System (EMS). For this purpose, the cost is the predominant and most often only factor taken into account in the literature, although in the residential sector other concerns influencing electricity consumption behaviour have been observed. This paper presents an EMS based on a neighbourhood of consumers modelled at the level of their appliance and incorporating 6 consumption profiles along three sensitivities: cost, environment and appliances shifting comfort. A multi-agent optimization is lead by a central aggregator but performed locally by the household using multi-pass Dynamic Programming (DP), thus ensuring privacy protection for the stakeholders.

Integrated Drives are a target in terms of simplicity in complex systems such as transportation. Anyway the integration of the power component inside the electrical machine induces challenges if the compactness is required. The CE2I project, for “Smart Integrated Drives”, searches to deal simultaneously with the constraints such as better thermal control and modelling, more efficient numerical virtual modelling for co-simulation, exploration of new materials and use of low losses, high frequency wide-band-gap (WBG) components.

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.

Integrated Drives are a target in terms of simplicity in complex systems such as transportation. Anyway the integration of the power component inside the electrical machine induces challenges if the compactness is required. The CE2I project, for “Smart Integrated Drives”, searches to deal simultaneously with the constraints such as better thermal control and modelling, more efficient numerical virtual modelling for co-simulation, exploration of new materials and use of low losses, high frequency wide-band-gap (WBG) components.

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.

Integrated Drives are a target in terms of simplicity in complex systems such as transportation. Anyway the integration of the power component inside the electrical machine induces challenges if the compactness is required. The CE2I project, for “Smart Integrated Drives”, searches to deal simultaneously with the constraints such as better thermal control and modelling, more efficient numerical virtual modelling for co-simulation, exploration of new materials and use of low losses, high frequency wide-band-gap (WBG) components.

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.

to ensure the operation of each wind turbine under a safe voltage level while no power production is lost in the wind farm. This paper first introduces the whole wind generation system. Then the steady state analysis of the dc series offshore wind farm and the overvoltage phenomenon are described, which lead to the proposal of the global control strategy. The detailed realization of the global control strategy by use of the MMC is given after a short recall of the MMC arm average model.

This study presents control strategies of offshore wind farms with dc series collector systems and modular multilevel converter based high voltage direct current (MMC-HVDC) transmissions. Series connection of dc wind turbines enables the collector system to establish the HVDC transmission voltage level with neither transformer nor centralized converter platform, indicating huge savings on offshore wind farm investment. However, severe wind variation imposes overvoltage on the wind turbines and may induce a cascade of failures of other series connected units. This paper first explains the wind farm design constrains bound by overvoltage limitation of wind turbine units. Then two kinds of control strategies, classical control and proposed HVDC global control, are presented to ensure every unit operating within safety limit. Wind farms with both control strategies are simulated. Finally, the two kinds of strategies are compared in terms of technical feasibilities, economical benefits and annual energy production rates. The results demonstrate that DC series offshore wind farms with proposed HVDC global control strategy imply competitive economic advantages of future integration of remote energy generation.

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 in 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 the 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 based on fuzzy logic approach and graphical methodology to build it. Simulation results are discussed for different scenarios cases and the reaction of the hybrid railway power substation is detailed.

Railway traffic increases and electricity market liberalization constrain the railway actors to consider new solutions to handle energy consumption. Hence, a technology change in the railway electrical systems is considered through the integration of renewable energy sources and storage units. In this context, a relevant methodology is proposed here for optimal design and operation analysis of railway hybrid power substations. This method is useful for the analysis and improvement of future railway power network efficiency.

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.

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 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.

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 output voltage waveform of a multilevel inverter is composed of several intermediary voltage levels, which are obtained from capacitor voltage sources. If the number of levels reaches infinity, the total harmonic distortion of the modulated voltage becomes practically zero. However, the numbers of the achievable voltage levels are limited by voltage unbalance problems, voltage clamping requirement, circuit layout, and packaging constraints. This paper presents a modulation strategy that enables to copy directly a modulated multilevel waveform on to output voltages of a (n+1) level inverter. The redundancies of different switch configurations are used to perform the voltage balancing of the DC link. The obtained modelling shows that high voltage multi levels are obtained by combination of n different three-level functions, which are called modulation functions. Therefore, a novel PWM strategy is designed to generate n fictive modulated voltage systems via the direct width modulation and the position setting of modulation functions. Simulation results are presented for a five-level inverter. Experimental results are given for a three-level inverter.

In this paper, a new control system for single phase five-level diode clamped inverters (DCI) is presented. The obtained modeling shows that high voltage multilevels are obtained by combination of four different three-level functions, which are called conversion functions. Therefore a novel PWM strategy is designed by a particular modulation for creating four fictive modulated voltage systems via the direct width modulation and the position setting of both conversion functions. Redundancies of different switch configurations for the generation of intermediate voltages are used to limit the deviations of capacitor voltages. A correct filtered AC output is obtained with a classical closed loop control. Experimental and simulation results for a three-level and five-level diode clamped inverter are presented to demonstrate the validity of the proposed balancing modulation.

El auge de las energías renovables y la necesidad de medios de transporte descarbonizados están dando un nuevo interés al almacenamiento de energía, que se ha convertido en un elemento clave del desarrollo sostenible. La gestión y valorización del almacenamiento de energía en las redes eléctricas presenta y compara las diferentes tecnologías de almacenamiento actualmente implementadas. Desde una perspectiva de desarrollo sostenible, estudia en particular la importancia de la gestión energética de los sistemas que combinan fuentes de energía renovables y unidades de almacenamiento para su integración sin problemas en redes inteligentes. Pedagógico, este libro también ofrece herramientas metodológicas y ejemplos concretos para establecer un sistema de gestión de la energía para el almacenamiento. Tabla de contenido 1. Problemas de almacenamiento de energía eléctrica 2. Situación actual del almacenamiento de energía 3. Valoración del almacenamiento de energía en las redes eléctricas 4. Introducción a la lógica difusa y aplicación a la gestión del almacenamiento inercial en un sistema híbrido eólico-diésel 5. Metodología para la construcción del supervisor de una fuente eólica asociada al almacenamiento 6. Construcción del supervisor de una fuente híbrida con múltiples fuentes y almacenamiento múltiple 7. Gestión y valorización de un sistema de almacenamiento adiabático de aire comprimido integrado en una red eléctrica

Les développements actuels dans le domaine des énergies renouvelables, ainsi que la tendance à l'autoproduction et à l'autoconsommation d'énergie, ont suscité un intérêt accru pour les moyens de stockage de l'énergie électrique; un élément clé du développement durable. Ce livre présente le potentiel offert par le stockage de l’électricité dans le cadre des bâtiments, îlots de bâtiments, quartiers intégrés dans un large réseau électrique intelligent ou « Smart Grid » ou formant un micro réseau électrique intelligent ou « Micro Grid », et tout particulièrement concernant leur gestion et leur valorisation. Il montre les nombreux services que le stockage peut apporter, et examine les facteurs socio-économiques importants liés à l’émergence de bâtiments intelligents et de réseaux intelligents. Enfin, il présente les outils méthodologiques nécessaires à la mise en place d'un système de gestion de l'énergie de ces technologies de stockage, illustrés par des exemples concrets et pédagogiques. Table des matières: 1. Problématique du stockage de l’énergie électrique dans l’habitat: vers des bâtiments et des villes plus intelligents. 2. Stockage énergétique dans un bâtiment commercial. 3. Stockage énergétique dans un bâtiment tertiaire, couplé à de la production photovoltaïque et de l’éclairage LED. 4. Stockage hybride associé à du photovoltaïque dans le contexte de l’habitat en zone non interconnectée. 5. Changements économiques et sociologiques induits par les smart grids. 6. Mutualisation énergétique entre bâtiments tertiaires, résidentiels et producteurs d’énergie. 7. Gestion centralisée d’une communauté locale énergétique permettant une autoconsommation maximale de l’énergie photovoltaïque. 8. Charge réversible des véhicules électriques vers les réseaux et les bâtiments.

Current developments in the renewable energy field, and the trend toward self-production and self-consumption of energy, has led to increased interest in the means of storing electrical energy; a key element of sustainable development. This book provides an in-depth view of the environmentally responsible energy solutions currently available for use in the building sector. It highlights the importance of storing electrical energy, demonstrates the many services that the storage of electrical energy can bring, and discusses the important socio-economic factors related to the emergence of smart buildings and smart grids. Finally, it presents the methodological tools needed to build a system of storage-based energy management, illustrated by concrete, pedagogic examples. Content: 1. Storing Electrical Energy in Habitat: Toward “Smart Buildings” and “Smart Cities”. 2. Energy Storage in a Commercial Building. 3. Energy Storage in a Tertiary Building, Combining Photovoltaic Panels and LED Lighting. 4. Hybrid Storage Associated with Photovoltaic Technology for Buildings in Non-interconnected Zones. 5. Economic and Sociological Implications of SmartGrids. 6. Energy Mutualization for Tertiary Buildings, Residential Buildings and Producers. 7. Centralized Management of a Local Energy Community to Maximize Self-consumption of PV Production. 8. Reversible Charging from Electric Vehicles to Grids and Buildings.

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.