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The voltage and current outputs of a power electronic converter contain high harmonic, especially when the required power operation point is less than the nominal one. The present paper proposes a new space vector modulation scheme to improve this harmonic content for the overall power range. This technique is based on an optimized distribution of the zero vectors during the sampling time. Firstly, a vector spatial approach of the voltage flux harmonic is analytically synthesized. Hence, the obtained flux harmonic trajectories are optimized somehow to minimize the distance between the gravity center of this trajectory and its origin, which gives the exact du- ration of the zero vectors. The obtained simulation and experimental results show an improved harmonic content of the output converter even for low modulation index and an enhanced converter current waveform. The results confirm the superiority of the proposed strategy compared to the previously developed.

This paper proposes a robust decoupling power algorithm based on a doubly fed induction generator (DFIG) for variable speed wind-turbine (WT). The DFIG rotor circuit is fed by the direct matrix converter (DMC), which presents several features such as no need to the dc-bus voltage, sinusoidal supply, rotor side waveforms, bidirectional power flow, and adjustable input power factor. The 18 bidirectional switches are controlled using the Venturini modulation technique. On the other hand, the DFIG stator circuit is connected directly to the grid. The nonlinear control strategy based on feedback linearization is applied to control the stator power (Ps and Qs) independently using the rotor quadrature and direct currents (irq and ird), which present the images of the previous stator powers. Some limitations appear in the power algorithm using the conventional pi controller, especially in power tracking, error, and quality. In this context, the model reference adaptive controller (MRAC) presents an alternative solution, a robust and efficient controller proposed instead of the pi controllers to control stator powers. Finally, the simulation results confirm that the proposed algorithm could work under hard conditions and demonstrate that the wind energy conversion system (WECS) provides enhanced dynamic responses in transient and steady states and good power quality delivered to the grid.

This paper presents a measurement-based under-frequency load shedding scheme that considers time delays, measurement uncertainties, and communication network faults. Using a moving first-degree polynomial function, an iterative approach to estimate the frequency nadir and the associated frequency nadir time is proposed. Then, a novel method to simultaneously estimate the power imbalance and the system inertia constant is developed. According to an analytical basis, a base system is selected from a set of pre-defined base systems to guarantee accurate power imbalance estimation. Finally, a mathematical index is investigated to calculate a threshold for the generation-load power imbalance beyond which loads should be shed. Further, a systematic approach for specifying the amount of load to be shed in each transmission bus of the system is proposed. The effectiveness of the proposed methodologies is examined on both simulated and actual measured data from 9 historical power system disturbances in a national power grid.

This paper presents a general operational planning framework for controllable generators, one day ahead, under uncertain re-newable energy generation. The effect of photovoltaic (PV) power generation uncertainty on operating decisions is examined by incorporating expected possible uncertainties into a two-stage unit commitment optimization. The planning objective consists in minimizing operating costs and/or equivalent carbon dioxide (CO 2 ) emissions. Based on distributions of forecasting errors of the net demand, a LOLP-based risk assessment method is proposed to determine an appropriate amount of operating reserve (OR) for each time step of the next day. Then, in a first stage, a deterministic optimization within a mixed-integer linear programming (MILP) method generates the unit commitment of controllable generators with the day-ahead PV and load demand prediction and the prescribed OR requirement. In a second stage, possible future forecasting uncertainties are considered. Hence, a stochastic operational planning is optimized in order to commit enough flexible generators to handle unexpected deviations from predic-tions. The proposed methodology is implemented for a local energy community. Results regarding the available operating reserve, operating costs and CO2 emissions are established and compared. About 15% of economic operating costs and environmental costs are saved, compared to a deterministic generation planning while ensuring the targeted security level.

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.

Abstract In electrical systems, the main objective is to satisfy the load demand at the least cost without having imbalance between generation and consumption. Thus, the uncertainty of photovoltaic (PV) power production must be considered in generation planning. In this paper, the optimal generation scheduling in an urban microgrid is made by taking in consideration operating reserve (OR) provision and under stochastic characteristics of PV power prediction. By considering a prescribed risk level of unbalancing, a dynamic programming (DP) algorithm sets the operational planning of conventional generators, so that the operational cost and available operating reserve can be calculated. Then, the effect of PV power uncertainty into the unit commitment is analysed by considering PV forecast intervals with a 95 % confidence level. The unit commitment is then recalculated with new generator set points and the same criteria. Finally, variations of the targeted minimized costs and obtained OR is analysed according to the considered uncertainty.

Low voltage distribution networks have not been traditionally designed to accommodate the large-scale integration of decentralized photovoltaic (PV) generations. The bidirectional power flows in existing networks resulting from the load demand and PV generation changes as well as the influence of ambient temperature led to voltage variations and increased the leakage current through the cable insulation. In this paper, a machine learning-based framework is implemented for the identification of cable degradation by using data from deployed smart meter (SM) measurements. Nodal voltage variations are supposed to be related to cable conditions (reduction of cable insulation thickness due to insulation wear) and to client net demand changes. Various machine learning techniques are applied for classification of nodal voltages according to the cable insulation conditions. Once trained according to the comprehensive generated datasets, the implemented techniques can classify new network operating points into a healthy or degraded cable condition with high accuracy in their predictions. The simulation results reveal that logistic regression and decision tree algorithms lead to a better prediction (with a 97.9% and 99.9% accuracy, respectively) result than the k-nearest neighbors (which reach only 76.7%). The proposed framework offers promising perspectives for the early identification of LV cable conditions by using SM measurements.

In this paper, the problem of optimal placement of virtual inertia is considered as a techno-economic problem from a frequency stability point of view. First, a data driven-based equivalent model of battery energy storage systems, as seen from the electrical system, is proposed. This experimentally validated model takes advantage of the energy storage system special attributes to contribute to inertial response enhancement, via the virtual inertia concept. Then, a new framework is proposed, which considers the battery storage system features, including annual costs, lifetime and state of charge, into the optimal placement formulation to enhance frequency response with a minimum storage capacity. Two well-known dynamical frequency criteria, the frequency nadir and the rate of change of frequency, are utilized in the optimization formulation to determine minimum energy storage systems. Moreover, a power angle-based stability index is also used to assess the effect of virtual inertia on transient stability. Sensitivity and uncertainty analyses are further conducted to assess the applicability of the method. The efficiency of the proposed framework is demonstrated on a linearized model of a three-area power system as well as two nonlinear systems. Simulation results suggest that the proposed method gives improved results in terms of stability measures and less ESS capacity, when compared with other methods proposed in the literature.

In Active Distribution Networks (ADNs), Distribution Company (Disco) follows two main strategies of dispatching of Distributed Energy Resources (DERs) and trading energy with wholesale energy markets, including Day-Ahead (DA) and Real-Time (RT) markets, to meet the demand. An attempt is made in this paper to model the strategic behavior of the Disco, in the wholesale DA and RT energy markets, through a bi-level optimization approach While the objective of the upper-level problem is to minimize the expected cost of the Disco, the lower-level problem (with two optimization problems) formulates to simultaneously maximize the social-welfare of the DA market and minimize the cost of the RT market. Furthermore, uncertain behavior of renewable energy sources as well as demand is tackled into the problem formulation. To this end, Disco decision-making represents as a risk-based two-stage stochastic problem where the Disco’s risk aversion is modeled using conditional value at risk (CVaR) method. Generally stated, the proposed model is a non-linear bi-level problem which may be transformed into a non-linear but single-level problem through Karush–Kuhn–Tucker (KKT) conditions and dual theory. Detailed numerical results on a 6-bus and RTS 24-bus power systems are used to demonstrate efficiency of the proposed model. Moreover, sensitivity analysis is carried out to investigate the effect of risk-aversion parameter on the decision making of the Disco and the offers/bids in both the DA and RT markets.

Accurate cable modeling is a recurrent issue for electric architecture evaluation and design, especially in specific contexts, like offshore wind farms. This paper proposes optimal analytical cable models for the technical and economic assessment of offshore wind generation systems. Proposed models evaluate the electrical and thermal behaviors of cables, as components of the complete offshore wind generation transmission system. The cost effectiveness of the latter is assessed by considering both CAPEX and OPEX contributions. A comparison with published models is also presented, and illustrated on various cable designs. Among others, we can see that the greater the section, the more interesting the simplification model is. Also, we checked that the model proposed by Brakelmann is correct in DC. For all other cases, the model, based on standards, is preferred. The proposed paper goes beyond cables modeling by describing an assessment method based on specific cables modeling, allowing the choice of cables within a holistic assessment tool bringing decision support regarding optimal design of offshore wind farm grid connection. A system assessment based on the proposed model is presented, for a typical HVAC architecture.

Small-sized variable renewable energy sources (RES) live a large-scale development in urban electrical systems. They increase local high dynamic unbalancing and then can create instabilities on the inertia response. Thus, setting an adequate operating reserve (OR) power to compensate the unpredicted imbalance between RES generation and consumption is essential for power system security. Indeed, effective calculation and dispatching of OR considering inaccurate forecast of both RES and load demand can provide substantial cost reductions. Thus, to facilitate the energy management and system optimization in an urban microgrid (MG), a user-friendly tool for Energy Management System and Operational Planning has been developed. The tool provides a complete set of user-friendly graphical interfaces to study the details of photovoltaic (PV) and batteries, load demand, as well as micro gas turbines (MGTs). Furthermore, this energy management system allows system operators to properly model RES uncertainty. In addition, it could assist operators for the day-ahead energy management with an efficient information system and an intelligent management.

Setting an adequate operating power reserve (PR) to compensate unpredictable imbalances between generation and consumption is essential for power system security. Operating power reserve should be carefully sized but also ideally minimized and dispatched to reduce operation costs with a satisfying security level. Although several energy generation and load forecasting tools have been developed, decision-making methods are required to estimate the operating power reserve amount within its dispatch over generators during small time windows and with adaptive capabilities to markets, as new ancillary service markets. This paper proposes an uncertainty analysis method for power reserve quantification in an urban microgrid with a high penetration ratio of PV (photovoltaic) power. First, forecasting errors of PV production and load demand are estimated one day ahead by using artificial neural networks. Then two methods are proposed to calculate one day ahead the net demand error. The first perform a direct forecast of the error, the second one calculates it from the available PV power and load demand forecast errors. This remaining net error is analyzed with dedicated statistical and stochastic procedures. Hence, according to an accepted risk level, a method is proposed to calculate the required PR for each hour.

Purpose Self-commuted voltage source converter (VSC) can significantly extend the flexibility and operability of an HVDC system and be used to implement the concept of multi-terminal HVDC (MTDC) grid. To take full advantage of MTDC systems, its overall behaviour must be characterized in quasi static and dynamic states. Based on the numerous literatures, a dedicated two-level VSC model and its local controllers and DC grid voltage regulators are developed for this purpose. Furthermore, the requirement of the system to guarantee all the physical constrains must be well assessed and concrete demonstrations must be provided by numerical simulations. Design/methodology/approach First, a two-level VSC model and its local controllers and DC grid voltage regulators are developed. Then, DC cable models are investigated and their characteristics are assessed in the frequency domain. Those developed models are combined to form a three-terminal HVDC grid system on Matlab/Simulink platform. To analyze the stability of this electrical system, the dynamics of the system against variations of power dispatch are observed. Findings To analyze the stability of this electrical system, the dynamics of the system against variations of power dispatch are observed. The differences in the DC grid voltage dynamics and the power flow of the converter stations coming from the embedded primary controls are analysed, and the technical requirements for both cases are assessed. Originality/value In this paper, the dynamic stability of an MTDC system has been analysed and assessed through an adequate simulation model, including its control scheme and the cable models. The interest of the improved PI model for cables is highlighted.

Grid operational challenges are significant to increase securely the wind penetration level. New embedded control functions are therefore required in order to make participate wind generators in power system management. In this paper the implementation of inertial response and primary frequency control in a wind turbine controller are investigated. Main factors affecting the performances of the frequency regulation are identified and characterized. The influence of control parameters and the turbine operating point on the inertial response are analyzed through obtained performances in an islanded power system. The combined control scheme using both controllers is also developed and the potential of the obtained grid service at partial load is discussed.

In electrical islands, frequency excursions are sizeable and automatic load shedding is often required in response to disturbances. Moreover, the displacement of conventional generation with wind and solar plants, which usually do not provide inertial response, further weakens these power systems. Fast-acting storage, by injecting power within instants after the loss of a generating unit, can back up conventional generation assets during the activation of their primary reserve. This paper relies on dynamic simulations to study the provision of such a dynamic frequency control support by energy storage systems in the French island of Guadeloupe with large shares of wind or solar generation. The results show that fast-acting storage, by acting as a synthetic inertia, can mitigate the impact of these sources on the dynamic performance of the studied island grid in the case of a major generation outage. The other concerns raised by renewables (e.g., variability, forecast accuracy, low voltage ride-through, etc.) have not been addressed within this project.

Matrix converters (MCs) are considered as a step forward in ac/ac conversion, providing sine-in and sine-out voltages and currents, controlled input power factor, compact sight without the requirement of a dc bus capacitor, and bidirectional power flows. There are also drawbacks associated with this technology: More switching devices and associated gate driver circuit power supplies and protection systems are required. In this paper, a new low-cost self-powered supply for bidirectional insulated-gate bipolar transistor/MOSFET switch gate drivers is presented. The proposed circuit allows the gate driver power supply of the bidirectional switch without using a transformer or any external added dc supply. This method is characterized by a simple structure, which is cost and size effective, of the power electronics switch driver power supply with regard to those suggested in the literature. Simulation results are compared with experimental measurements for a three-phase-to-single-phase MC and validate the proposed circuit.

The development of energy management tools for next-generation PhotoVoltaic (PV) installations, including storage units, provides flexibility to distribution system operators. In this paper, the aggregation and implementation of these determinist energy management methods for business customers in a microgrid power system are presented. This paper proposes a determinist energy management system for a microgrid, including advanced PV generators with embedded storage units and a gas microturbine. The system is organized according to different functions and is implemented in two parts: a central energy management of the microgrid and a local power management at the customer side. The power planning is designed according to the prediction for PV power production and the load forecasting. The central and local management systems exchange data and order through a communication network. According to received grid power references, additional functions are also designed to manage locally the power flows between the various sources. Application to the case of a hybrid supercapacitor battery-based PV active generator is presented.

This article draws attention to problems important for all EU power consumers—the unfairness in individual payments for power transmission and in the cross-border subsidy element in the mechanism of Inter-Transmission System Operators (TSO) Compensation (ITC). A brief review of power transmission tariffs brings out the structure of the problems. A short retrospection explains their growth. The essence of the ITC mechanism is explained and existing shortcomings are illustrated. The deficiencies of existing regulations for transmission pricing are analyzed. In the light of this analysis, the ITC problem is reconsidered and defined more precisely. The basic prerequisites to an ITC reformulation process are presented. The main principles of a new simple, transparent and equitable approach are suggested, in accordance with the contemporary legal positions and functions of the TSOs.

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.

This paper deals with the energy management of a photovoltaic based power station. This power station includes storage units with batteries for long-term energy supply and ultracapacitors for fast dynamic power regulation. According to the availability of the primary source, the level of the stored energy and the request from the grid operator, we have defined and detailed three main operating modes for this system with a particular modeling tool: Petri nets. For each operating mode, we have designed an energy management algorithm in order to calculate the energy dispatching of an adjustable power margin for the storage units.

This paper deals with the results of a study aiming to assess the suitability of various energy storage technologies for medium-term (2015) integration into distribution systems. Based on a review of many scientific and industrial materials, and by taking into account a few hypotheses, a shortlist of some properties to consider was first identified and defined. More than twenty storage techniques were then studied and nine of them were found to be particularly suited. An up-to-date overview of their performances is given at the end of the article.

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.

Power systems are often subject to various types of disturbances, which may carry of serious damages in the elements of system components (generators, receptors, storage elements, power control systems). The production-consuming balancing is therefore not insured. Consequently, the system becomes transiently instable. Various researchers and authors in the area of assessment and improvement of power system transient stability have published much previous works. Since the study of the transient stability is complex and includes modeling of all component of the power system as well as the control systems, different models and analysis methods have been proposed and described in the literature. This paper presents a state of the art of assessment of power system transient stability.

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 fault tolerant AC-AC converter capable of supplying a three-phase induction machine from the grid with an unitary power factor has been proposed. With one faulted converter leg, two of the remaining five legs are connected to the grid, two legs are connected to the machine and a common leg is shared by the grid and the machine. The previously developed control strategy required a too great computation time for practical implementation. In this paper, a new control strategy is suggested for this power converter. It enables an easier control implementation. Experimental results are provided.

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.

A multi-machine multi-converter system formalism has been proposed to describe systems composed of several electrical machines and converters. This description points out coupling elements, which have to distribute energy. Control structures have already been proposed for systems with downstream coupling. This paper is focused on control structures for systems with upstream coupling. Several solutions can be found by moving control blocks

Cet article propose une réflexion sur les services que des unités de stockage d’énergie pourraient apporter à la planification et à l’exploitation des réseaux de distribution, comme le renvoi de tension en poche locale par exemple. En dépit d’intérêts techniques forts, une unique application ne suffit généralement pas à rentabiliser de tels dispositifs, dont le coût demeure élevé. C’est pourquoi, dans les limites des possibilités des technologies disponibles, il est nécessaire de mutualiser un maximum de fonctions auprès de différents acteurs du système électrique de façon à cumuler plusieurs sources de valeur. Pour aider à l’identification d’offres de services envisageables dans ce cadre, une méthode d’étude intégrant la localisation du système de stockage au sein du réseau est introduite. --- This paper deals with the new services that can be provided by distributed energy storage systems to enhance distribution planning and operation, such as intentional islanding. Although energy storage technologies offer interesting features, they still remain capital-intensive and raise cost-competitiveness issues: they usually cannot be made profitable considering only a single revenue stream. That is why it seems necessary to contemplate the possible services of energy storage not only for distribution system operators, but for some other stakeholders of the electricity value chain as well. In the last part, a new approach to the combination of storage benefits is introduced and its use within the framework of this project is briefly discussed.

Dans cet article, une représentation par modèles moyens pour les convertisseurs est utilisée pour concevoir un modèle dynamique d’un générateur basé sur la microturbine pour un microréseau isolé. Une modélisation spécifique est conçue pour quantifier les variations énergétiques au sein des éléments de stockage (rotor de la machine, bus continu) et pertes. On constate que cette modélisation est suffisante pour concevoir le dispositif de commande de l’ensemble du système de génération, y compris de la microturbine, la machine synchrone et le convertisseur de fréquence. Le modèle proposé est simulé à l’aide de Matlab-SimulinkTM en utilisant une microturbine de Capstone C330 en fonctionnement isolé.

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).

Un formalisme a été mis en place pour l’analyse de systèmes composés de plusieurs machines électriques et/ou plusieurs convertisseurs statiques. Il permet de mettre en évidence les trois couplages possibles dans les chaînes de conversion électromécanique : couplage électrique, magnétique ou mécanique. Des règles basées sur le principe d’inversion permettent de proposer des structures de commande pour de tels systèmes. Des critères de répartition énergétique doivent ainsi être mis en œuvre. Plusieurs exemples d’application très divers montrent l’intérêt de ce formalisme.

The structure of the Low Voltage distribution networks is not always accurately known by the Distribution System Operators, especially with the significant meteorological variations observed in recent years and the growth of decentralized PV production sources. In this paper a probabilistic Load Flow algorithm has been developed for radial Low Voltage network considering the line resistance distribution as an uncertainty depending on the temperature. The single-phase network model is therefore associated to the temperature variation in the network deployment area. The Load demand and the PV production generally used in classical Load Flow calculation are computed using Smart Meter data with a quarter of an hour resolution time. Both power values are considered to be time varying. Either the resistance value or the network to client exchanged power are randomly selected at each iteration using a Monte Carlo method. Both annual and seasonal dependencies of the line resistance have been implemented in the developed Probabilistic Load Flow. The simulation results have shown that integrating the resistance distribution in a seasonal probabilistic tool can impact the collected reliability indices up to 10.4% depending on the season. In a context of upgrading the Low Voltage electrical network knowledge by the Distribution System Operator, and with an accordance to the requirements of the EN50160 standard, this tool can be presented as an efficient algorithm for quantifying the impact of the line resistance statistical distribution on a Probabilistic Load Flow computation.

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.

This paper presents a comparative analysis of the dynamic behavior of a Modular Multi-level Converter (MMC) with grid-forming control either with or without controlling the MMC internal energy. It has been demonstrated that the internal energy of the MMC in low-level control interacts with the high-level control, which is performed by a grid-forming scheme. In case of controlling the internal energy of the MMC, this interaction is mitigated. Moreover, it has been shown that the dynamic behavior of a grid-forming controlled MMC with internal energy control is identical to an equivalent 2-level Voltage Source Converter (VSC).

This paper presents an application of Evolutionary Computation (EC) to the benchmark of the safety isolating transformer problem. The benchmark adopts multidisciplinary optimization strategies, namely the multidisciplinary feasible (MDF) and the individual discipline feasible (IDF) formulations. The benchmark meets the requirements of engineers and scientists working with machine design problem, such as in the first part of the design process that is the choice of structure and materials. The EC methods employed in this paper are based on Evolutionary Algorithms (EAs), namely two variants of Differential Evolution (DE), two variants of Hybrid Adaptive DE (HyDE) and the Vortex Search (VS). The results showed in this paper suggest that EA methods are competitive with the classical optimization method, the sequential quadratic programming (SQP). Among the developed EAs, HyDE-DF is able to obtain better values than SQP on a significant battery of trials.

High levels of renewable generation incorporation increase the flexibility requirements of the electrical system in response to fast and large variations in load and renewable energy output. Advanced power system operational methods and algorithm are required to schedule the generating units with more reliability and efficiency. In order to deal with uncertainties in generation planning of an urban microgrid, this paper presents a storage control strategy for reserve provision in a multi-objective scenario-based stochastic optimization algorithm. Power reserve allocation is optimized while uncertainties from renewable energy and load demand are taken into account. Results confirm that the presented algorithm ensures that storage-hybridized RESs contributes to the primary source of reserve capacity, and the performance in terms of security level are highlighted.

Voltage variations that occur in the Low Voltage (LV) distribution networks are caused by different factors such as the load demand changes, intermittent powers of photovoltaic (PV) generation, the phenomena related to the operating environment of the network and their influence on the physical structure of the network, network faults, etc. The voltage variations can have important adverse impacts on the connected equipment. This paper aims to analyze the electrical conductance variation of the cable insulation, due to the degradation of the insulating material, and its impact on the nodal voltages. To this end, a probabilistic framework is proposed based on the Monte Carlo (MC) simulations and load flow calculations. The MC simulations are used here in order to characterize the insulation degradation of lines through scenarios and to model the resistance variation of lines. Considering the load demand and photovoltaic generation in a single-phase network as well as line the impedance data, in different degradation conditions, load flow calculations are conducted in order to calculate the nodal voltages. Simulation results reveal voltage drops over 50% depending on the position, number and degree of the cable insulation degradation as well as on the network working conditions. This result offers promising perspectives for the detection of cable degradations by use of Smart Meter (SM) voltage measurements.

This paper investigates the effect of using phaselocked loop (PLL) on the performance of a grid-forming controlled converter. Usually, a grid-forming controlled converter operates without dedicated PLL. It is shown that in this case, the active power dominant dynamics are highly dependent to the grid short circuit ratio (SCR). In case of using PLL, the obtained results illustrate that the SCR has a negligible effect on the dynamic behavior of the system. Moreover, the power converter will not participate to the frequency regulation anymore; therefore, the converter response time can be adjusted independently to the choice of the droop control gain, which is not possible without PLL. A simple equivalent model is presented which gives a physical explanation of these features.

This paper attempts a detailed comparison of some of the solutions for the black start of the Offshore Wind Power Plants with Diode Rectifier based HVDC transmission. The major challenges and control requirements to ensure the black start operation are explained following a brief review of the existing capabilities of wind generators. The various solutions surveyed as part of the study are presented along with a detailed comparison. Moreover, a case study is simulated, supported by calculations to highlight the power requirements of the offshore grid during black start, enabling further assessment of the black start solutions discussed.

In electrical systems, the main objective is to ensure that users demand is met at the least cost without having imbalance between generation and consumption. Thus, the uncertainty of photovoltaic (PV) power production must be considered in generation planning. In this paper, the optimal generation scheduling including the operating reserve (OR) provision are developed under stochastic characteristics of PV renewable energy in an urban microgrid. With a prescribed risk level of unbalancing, a dynamic programming (DP) algorithm sets the operational planning of conventional generators. Then, the operational cost and available operating reserve can be calculated. The effect of PV power uncertainty into UC is then analyzed by considering forecast intervals of PV forecasting. The proposed methods consider PV prediction uncertainties with a 95% confidence level. The unit commitment is then recalculated as well as new generator set points with same criteria. Hence, variations of the targeted minimized costs and obtained OR is analysed according to the considered uncertainty.

The role of Modular Multilevel Converters (MMCs) in HVDC grid greatly differs depending on whether it is an offshore or an onshore station. From the common point in their control schemes, an unexploited ability of the MMC—the controllability of the internally stored energy—is identified in both offshore and onshore applications. The virtual capacitor control, previously proposed by the authors, makes use of this degree of freedom to provide energy contribution to the DC grid. The impact of this control is demonstrated by time-domain simulations of a five-terminal HVDC grid.

Diode Rectifier (DR) based HVDC transmission can significantly reduce system costs and foot print of an HVDC power station for Offshore Wind Farms (OWFs), but the control of the offshore AC grid becomes challenging. The replacement of the offshore Voltage Source Converter (VSC) by a passive DR leads to major research questions pertaining to the control of the offshore AC grid. To achieve the wind farm operation and seamless power extraction, many grid forming solutions have been devised. This paper reviews a few of the major control solutions for AC grid forming and operation of DR-HVDC based OWFs, following which a comparison is made between them. Then two of these solutions are implemented in a study case electrical architecture. By using the simulation results and further analyses, the approaches adopted by these two solutions are elaborated further and the various challenges regarding the operation and control of the DR-HVDC based OWF are highlighted.

Electrical system operators and automatic controllers use Operating Reserve (OR) power to mitigate the unexpected imbalance between power supply and load demand. This backup power should be carefully sized and dispatched to reduce operation costs while keeping a satisfying security level. With the integration of small sized intermittent renewable generators in distribution networks, the allocation of OR where they are connected is interesting in order to compensate directly these uncertainty sources and maintain the security and reliability. In this paper, we consider the provision of OR directly by distributed PV generators combined with energy storage systems. For an urban microgrid, comparisons are given with the OR provision by a micro gas turbine. A method for dynamic joint dispatching of OR power on both generator types is presented and tested. Results show new insights in the possibilities of OR dispatching with renewable energy sources.

This paper defines a three level 48 pulse STATCOM based on GTO-VSC which is used to support the integration of remote large offshore wind farms into the main onshore grid using line-commutated high-voltage dc connection (LCC-HVDC). This mature transmission technology requires a large quantity of reactive power. In order to enhance the dynamic performance of the LCC-HVDC connected to a weak system, this work presents STATCOM applications to improve the power quality and to avoid commutation failures. Simulation results show that HVDC LCC technology connected to a weak system needs extra reactive power compensation. It confirms the STATCOM performance and its dynamic and fast reactive power compensation during voltage fault conditions. Finally, the sizing of the STATCOM dc capacitor is studied.

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.

The paper presents a tool for technical and economic assessment of offshore wind power connecting architectures; they highly influence cost effectiveness of offshore wind generation, particularly when power electronic converter based transmission technologies and long distance transmission cables are employed. Due to its models flexibility and accuracy, the developed tool is powerful for analysis and design of innovative connection alternatives.

Due to renewable energy sources (RES) variable nature and their wide integration into power systems, setting an adequate operating power reserve is important to compensate unpredictable imbalance between generation and consumption. However, this power reserve should be ideally minimized to reduce system cost with a satisfying security level. Although many forecasting methodologies have been developed for forecasting energy generation and load demand, management tools for decision making of operating reserve are still needed. This paper deals with power reserve quantification through uncertainty analysis with a photovoltaic (PV) generator. Indeed, using an artificial neural network based predictor (ANNs), PV power and load have been forecasted 24 hours ahead, and also forecasting errors have been predicted. Through forecasting uncertainty analysis, the power reserve quantification is calculated according to various risk indexes.

Renewable energy sources have a variable nature and are greatly depending on weather conditions. The load is also uncertain. Hence, it is necessary to use power reserve equipment to compensate unforeseen imbalances between production and load. However, this power reserve must be ideally minimized in order to reduce the system cost with a satisfying security level. The quantification of power reserve could be calculated through analysis of forecasting uncertainty errors of both generation and load. Therefore, in this paper, a back propagation artificial neural network approaches is derived to forecast solar radiations. Predictions have been analyzed according to weather classification. Some error indexes have been introduced to evaluate forecasting models performances and calculate the prediction accuracy. Forecasting results can be used for decision making of power reserve for renewable energy sources system with some probability or possibility methods.

In electrical islands, frequency excursions are sizeable and automatic load shedding is often required in response to disturbances. By injecting power in the timeframe of hundreds of milliseconds up to seconds after the loss of a generating unit, fast-acting storage can support the conventional production assets during the activation of their primary reserve. Using dynamic and real-time simulations, the provision of such a dynamic frequency control support by distributed energy storage systems has been studied in the case of the French island of Guadeloupe. Dedicated control algorithms have been developed and tested on a small-scale ultracapacitor storage unit. By acting as a virtual inertia, it has been shown that fast storage systems can improve substantially the dynamic performances of electrical islands.

This paper describes a design process of advanced grid equipment including both dynamic simulations and power-hardware-in-the-loop. A case study concerning the insertion of an energy storage system in a large isolated grid is used as an illustrative example. First, the methodology developed to achieve a real-time simulation of the studied grid from its original dynamic model is presented. The real-time platform used within the framework of this project is based on the RT-LAB environment and is interfaced with real ultracapacitors through a power amplifier. Some experimental results are analyzed in the final part. The advantages of this methodology including power-hardware-in-the-loop are emphasized by illustrating its contribution to dynamic model validation and the obtained improvement in control system performances.

This paper deals with distributed energy storage systems and reviews the services such devices can provide to the stakeholders of the electricity value chain. The combination of these applications to increase the overall value of energy storage is then studied using a new method.

This paper deals with the results of a study aiming to assess the suitability of various energy storage technologies for medium-term (2015) integration into distribution systems. Based on a review of many scientific and industrial materials, and by taking into account a few hypotheses, a shortlist of some properties to consider was first identified and defined. More than twenty storage techniques were then studied and nine of them were found to be particularly suited. An up-to-date overview of their performances is given at the end of the article.

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 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.

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 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.

Beaucoup de questions restent posées sur la façon dont les éoliennes peuvent être intégrées de façon massive et de manière systématique dans les réseaux électriques. Les réponses à apporter sont à relativiser selon la technologie d’éolienne utilisée pour convertir l’énergie d’origine éolienne en énergie électrique. En effet, le nombre de sites exposés de façon régulière à des vitesses importantes de vent étant limité, les constructeurs développent des éoliennes de puissance de plus en plus importante de façon à rentabiliser au maximum l’exploitation de cette ressource. Etant donné les niveaux de puissance, ces éoliennes sont généralement raccordées sur le réseau de distribution de moyenne tension, lorsqu’il s’agit de machines isolées ou de petits ensembles de quelques unités. Les centrales éoliennes de plus grande taille (dizaines de machines) doivent, quant à elles, être directement raccordées en haute tension, sur le réseau de transport ; c’est notamment ce qui est prévue pour les centrales off shore. Cet exposé rappelle tout d’abord les différentes technologies d’éolienne développées pour de tels niveaux de puissance en rappelant auparavant le principe de la conversion d’énergie à vitesse variable. L’installation massive de ce mode de production n’est pas sans conséquence sur la structure existante et le fonctionnement des réseaux électriques. Nous examinerons deux points cruciaux : l’influence sur la tension et le comportement de ce mode de production face à un incident provenant du réseau (typiquement le comportement dynamique suite à l’apparition d’un creux de la tension). Concernant l’influence sur la tension, une modification de la valeur efficace peut apparaître suivant l’éloignement des éoliennes d’une sous station de raccordement. Une solution consiste alors à implanter un réglage de la puissance réactive à l’aide d’un SVC. Une seconde solution consiste à utiliser une unité de stockage (batterie, volant d’inertie) permettant de corriger les variations rapides de la tension mais aussi permettant de lisser (de manière active) la puissance générée (par l’implantation de courbes de statisme puissance/fréquence). Il est également possible de faire participer directement le générateur éolien au réglage de la tension. L’implantation de ce service au système électrique sera illustrée au travers d’une application concernant une éolienne à vitesse variable reposant sur une machine asynchrone et d’une application concernant une éolienne basée sur une machine asynchrone à double alimentation (MADA). Les problèmes liés à la sensibilité des éoliennes, par rapport à des défauts provenant du réseau seront ensuite exposés. Là encore des solutions existent par l’emploi de systèmes permettant la restauration dynamique de la tension (Dynamic Voltage Restorer). On peut également envisager une reconfiguration du dispositif de commande de l’éolienne qui, sous ces conditions de fonctionnement, ne doit plus fonctionner en extraction du maximum de puissance mais venir en secours du réseau. Ce service constitue également une illustration de l’apport possible des éoliennes au service système. Plan de l’exposé : 1) Introduction 2) Technologies of WECS in distribution networks 3) Standard about harmonic generation 4) Voltage control 4.1) Problems 4.2) External solutions (direct connexion, SVC) 4.3) Integration of ancillary services 4.3.1) Reactive power control Application to the variable speed wind induction generator Application to the variable speed wind DFIG 4.3.2) Active power control 5) Influence on the power system 5.1) Problems : sensibility to faults 5.2) External solutions (DVR) 5.3) Integration of ancillary services, reconfiguration of the control system

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.

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.

An equivalent continuous dynamic model of a fuel cell generator and wind energy conversion system is proposed in this paper. It is shown that this model is interesting for analyzing the dynamic behavior of the system and for designing the control strategy. The proposed global model is simulated with the help of Matlab-Simulink™, by considering a 400 W wind generator and a Proton Exchange Membrane Fuel Cell (PEMFC) generator. This hybrid system is connected to a distribution network which is simulated with the help of the Power System Blockset™ (PSB) toolbox.

Ce manuel propose des résumés de cours, des exercices et problèmes corrigés couvrant l’ensemble des systèmes d’énergie renouvelable. Il inclut également des tendances actuelles telles que le stockage de l’énergie solaire et l’autoconsommation photovoltaïque ou éolienne. Les exercices et les problèmes sont classés par niveau de difficulté et par compétences et sont corrigés de manière détaillée. De nombreux exemples sont fournis avec les calculs et les graphiques aidant à visualiser les différentes technologies et méthodologies mathématiques. Cet ouvrage s’adresse aux étudiants de BTS, BUT, des cycles universitaires et des écoles d’ingénieurs.

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.

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 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 XXIe 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. 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. Des systèmes de production d’électricité à partir de ressources énergétiques renouvelables de petites et moyennes puissances sont présentés. La deuxième édition de cet ouvrage, revue et augmentée, met à jour les nombreuses données caractérisant le développement de ces énergies renouvelables, aborde les nouvelles technologies émergentes photovoltaïques et marémotrices exploitant les courants marins, le développement de l’éolien offshore, et les développements récents concernant l’intégration de ces sources dans le réseau électrique, ainsi que le développement de l’autoproduction et de l’autoconsommation. Plusieurs exercices sont proposés au lecteur à des fins d’évaluation. 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, 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 et Jonathan Sprooten.

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 second edition of this book, revised and expanded, updates the numerous data characterizing the development of these renewable energy sources, discusses new emerging photovoltaic and tidal technologies exploiting marine currents, the development of offshore wind power, and the recent developments concerning the integration of these sources into the electricity grid, as well as the development of self-production and self-consumption. Several exercises are provided to the reader for evaluation purposes. Contents 1. 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, Benoît Robyns and Antoine Henneton. 5. Thermal Power Generation, Jonathan Sprooten. 6. Integration of the Decentralized Production into the Electrical Network, Benoît Robyns and Jonathan Sprooten.

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.

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.