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Gestion prévisionnelle des réseaux actifs de distribution - relaxation convexe sous incertitude / Operational Planning of Active Distribution Networks - Convex Relaxation under UncertaintySwaminathan, Bhargav Prasanna 22 September 2017 (has links)
Les réseaux électriques subissent deux changements majeurs : le taux croissant de générateurs d’énergie distribuée (GED) intermittents et la dérégulation du système électrique. Les réseaux de distribution et leurs gestionnaires (GRD) sont plus particulièrement touchés. La planification, construction et exploitation des réseaux de la plupart des GRD doivent évoluer face à ces change- ments. Les réseaux actifs de distribution et la gestion intelligente de associée est une solution potentielle. Les GRD pourront ainsi adopter de nouveaux rôles, interagir avec de nouveaux acteurs et proposer de nouveaux services. Ils pourront aussi utiliser la flexibilité de manière optimale au travers, entre autres, d’outils intelligents pour la gestion prévisionnelle de leurs réseaux de moyenne tension (HTA). Développer ces outils est un défi, car les réseaux de distribution ont des spécificités techniques. Ces spécificités sont la présence d’éléments discrets comme les régleurs en charge et la reconfiguration, les flexibilités exogènes, la non-linéarité des calculs de répartition de charge, et l’incertitude liée aux prévisions des GED intermittents. Dans cette thèse, une analyse économique des flexibilités permet d’établir une référence commune pour une utilisation rentable et sans biais dans la gestion prévisionnelle. Des modèles linéaires des flexibilités sont développés en utilisant des reformulations mathématiques exactes. Le calcul de répartition de charge est “convexifié” à travers des reformulations. L’optimalité globale des solutions obtenues, avec ce modèle d’optimisation exact et convexe de gestion prévisionnelle, sont ainsi garanties. Les tests sur deux réseaux permettent d’en valider la performance. L’incertitude des prévisions de GED peut pourtant remettre en cause les solutions obtenues. Afin de résoudre ce problème, trois formulations différentes pour traiter cette incertitude sont développées. Leurs performances sont testées et comparées à travers des simulations. Une analyse permet d’identifier les formulations les plus adaptées pour la gestion prévisionnelle sous incertitude. / Power systems are faced by the rising shares of distributed renewable energy sources (DRES) and the deregulation of the electricity system. Distribution networks and their operators (DSO) are particularly at the front-line. The passive operational practives of many DSOs today have to evolve to overcome these challenges. Active Distribution Networks (ADN), and Active Network Management (ANM) have been touted as a potential solution. In this context, DSOs will streamline investment and operational decisions, creating a cost-effective framework of operations. They will evolve and take up new roles and optimally use flexibility to perform, for example, short-term op- erational planning of their networks. However, the development of such methods poses particular challenges. They are related to the presence of discrete elements (OLTCs and reconfiguration), the use of exogenous (external) flexibilities in these networks, the non-linear nature of optimal power flow (OPF) calculations, and uncertainties present in forecasts. The work leading to this thesis deals with and overcomes these challenges. First, a short-term economic analysis is done to ascertain the utilisation costs of flexibilities. This provides a common reference for different flexibilities. Then, exact linear flexibility models are developed using mathematical reformulation techniques. The OPF equations in operational planning are then convexified using reformulation techniques as well. The mixed-integer convex optimisation model thus developed, called the novel OP formulation, is exact and can guarantee globally optimal solutions. Simulations on two test networks allow us to evaluate the performance of this formulation. The uncertainty in DRES forecasts is then handled via three different formulations developed in this thesis. The best performing formulations under uncertainty are determined via comparison framework developed to test their performance.
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The Europeanisation of Ireland’s Wind Power Development. How is the EU policy process infleuncing the Irish wind sector?O'Connor, Feilim January 2014 (has links)
Ireland is facing a great challenge in meeting renewable energy requirements, where due to past circumstances and decisions, the nation state is now heavily dependent on imported fossil fuels. Given the contribution of these imported fossil fuels to global climate change, price instability and supply insecurity, Ireland is under a pressing need to face up to the dilemma of an unsustainably fueled economy. This thesis explores how the EU policy process is helping Ireland to achieve the goals it has set with the EU and how these are being incorporated into the drivers of wind power development in Ireland. This research sought to uncover the dynamic of this relationship - the goodness of fit - through an assessment of three mechanisms of change, namely: Discourses, Directives and Finances, which were drawn on from the theoretical approach of Europeanisation. By doing a combined assessment of these three channels and their influence, this thesis provides a greater understanding of the ways in which the development of wind power in Ireland is influenced by the EU level. The thesis finishes with a concluding discussion on the importance of the national level in this process, as well as the importance of social and community engagement, which despite being previously seen as important, has to date largely manifested as a tokenistic gesture in Ireland. This thesis reasserts it as a common and crucial thread of the renewable energy transition that continuously arose as being pre-eminent during this study.
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Architectures des marchés de l'électricité pour la sécurité d'approvisionnement à long terme dans un contexte de transition énergétique / Electricity market design for long-term capacity adequacy in a context of energy transitionOusman Abani, Ahmed 24 June 2019 (has links)
La transition énergétique, en partie caractérisée par le déploiement massif des énergies renouvelables, a relancé un débat de longue date sur les architectures de marché fournissant les meilleures incitations aux investissements dans les marchés libéralisés de l’électricité. Ces incitations sont essentielles pour garantir la sécurité d’approvisionnement à long terme. Pour choisir l’architecture de marché adéquate, les décideurs publics doivent évaluer et comparer les performances économiques des solutions disponibles. La présente thèse complète la littérature sur les incitations aux investissements et la sécurité d’approvisionnement en étudiant trois aspects importants : (i) le comportement des marchés de l'électricité en présence d’acteurs averses au risque, (ii) la compatibilité entre les incitations des acteurs à mettre leurs actifs sous cocon et les objectifs de sécurité d’approvisionnement et (iii) les performances économiques de différentes architectures de marché dans un contexte de forte pénétration des énergies renouvelables. Pour ce faire, une modélisation de type System Dynamics est utilisée pour représenter les dynamiques de long terme résultant des décisions des acteurs dans un marché libéralisé. La thèse est organisée en trois chapitres correspondant à chacun des points mentionnés ci-dessus. Les principaux résultats sont les suivants : Premièrement, les mécanismes de capacité sont nécessaires pour faire face aux effets néfastes de l’aversion au risque des investisseurs. Ce phénomène affecte de manière significative les marchés de l’énergie de type energy-only, qui subissent alors une baisse des investissements et des pénuries plus importantes. Les marchés de capacité résistent mieux à l’aversion au risque des investisseurs. Cependant, cette résilience dépend du plafond des prix dans les enchères de capacité. Pour qu'une telle architecture de marché donne des résultats satisfaisants en termes de sécurité d’approvisionnement, ce plafond de prix doit tenir compte du risque d'investissement supporté par les acteurs. Deuxièmement, si les acteurs du marché en ont la possibilité, leurs décisions de mettre leurs actifs sous cocon peuvent modifier les dynamiques d'investissement et de fermeture à long terme. En outre, dans un monde caractérisé par des actifs indivisibles, cette possibilité augmente le niveau de coordination nécessaire pour assurer la sécurité d’approvisionnement. Cela est particulièrement vrai pour les marchés de type energy-only, dans lesquels la mise sous cocon augmente le niveau des pénuries, au point de contrebalancer les économies de coûts qu’elle génère. En revanche, les marchés de capacité peuvent fournir la coordination nécessaire pour assurer la sécurité d’approvisionnement même lorsque les acteurs ont la possibilité de mettre leurs actifs sous cocon. Troisièmement, parmi les architectures de marché proposées dans la littérature, les marchés de capacité apparaissent comme la meilleure solution du point de vue du surplus social. Néanmoins, du point de vue des investisseurs, et dans certaines conditions liées à une forte pénétration des énergies renouvelables, les marchés de capacité avec des contrats annuels ne suppriment pas entièrement le problème dit de "missing money". Les résultats indiquent que l'attribution de contrats de capacité pluriannuels atténue le problème. / The ongoing energy transition, partly characterized by the massive deployment of renewables, has reignited a long-lasting debate on the best market design options to provide adequate investment incentives and ensure capacity adequacy in liberalised electricity markets. To choose the appropriate market design, policymakers need to assess and compare the economic performances of available solutions in terms of effectiveness and cost-efficiency. This dissertation complements the existing literature on market design for long-term capacity adequacy by focusing on three research topics: (i) understanding how electricity markets perform under different assumptions regarding investors’ risk preferences, (ii) analysing the compatibility of private agents’ incentives to mothball capacity resources with security of supply objectives and (iii) assessing the economic performance of different market designs in a context of a high penetration of renewables. To this end, the System Dynamics modelling framework is applied to represent long-term dynamics resulting from private agents’ decisions in liberalised electricity markets. The dissertation is organised in three chapters corresponding to each of the topics mentioned above. The main results are outlined below. Firstly, capacity remuneration mechanisms are necessary to deal with the detrimental effects of investors’ risk aversion. Energy-only markets are significantly affected by this phenomenon as they experience reduced investment incentives and higher levels of shortages. Capacity markets are more resilient to private investors’ risk aversion. However, this resilience depends on the level of the price cap in the capacity auctions. For such a market design to provide satisfactory outcomes in terms of capacity adequacy, this price cap should account for the investment risk faced by market participants. Secondly, when market participants have the possibility to mothball their capacity resources, these mothballing decisions can potentially modify investment and shutdown dynamics in the long run. Furthermore, in a world with capacity lumpiness (i.e. indivisibilities), mothballing increases the level of coordination needed to ensure capacity adequacy. This is especially true in energy-only markets, where mothballing increases the level of shortages to an extent that seems to overweigh the cost savings it generates at system level. Capacity markets can provide the required coordination to ensure capacity adequacy in a world with mothballing. Thirdly, among proposed market designs in the literature, capacity markets appear as the preferable solution to ensure capacity adequacy from a social welfare point of view. Nevertheless, from a private investor’s perspective and under certain conditions related to high penetration of renewables, capacity markets with annual contracts do not entirely remove the so-called “missing money” problem. The results indicate that granting multiannual capacity contracts alleviates the problem.
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Tři eseje o trhu s elektřinou / Three Essays on Electricity MarketsLuňáčková, Petra January 2018 (has links)
DISSERTATION - Abstract in English Three Essays on Electricity Markets Author: PhDr. Petra Luňáčková Academic Year: 2017/2018 This thesis consists of three papers that share the main theme - energy. The articles introduce characteristics and behavior of electricity focusing on its unique properties. The dissertation aims at the Czech electricity market and analyzes also highly discussed solar power plants. The first article studies long term memory properties of electricity spot prices through the detrended fluctuation analysis, as electricity prices are dominated by cycles. We conclude that Czech electricity prices are strongly mean reverting yet non-stationary. The second part of the dissertation investigates possible asymmetry in the gas - oil prices adjustment. Oil prices determine the price of electricity during the times of peak demand, as the reaction of power plants fueled by oil is quick but marginal costs are high. We chose the gasoline - crude oil relationship known as "rockets and feathers" effect and offer two new tests to analyze such type of relationship as we believe that error correction model is not the most suitable tool. Analyzing international dataset we do not find statistically significant asymmetry. The third study assesses the impact of renewable energy sources, solar plants in...
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OPTIMIZATION OF ONBOARDSOLAR PANELGEOMETRYFOR POWERING AN ELECTRIC VEHICLEJoseph L Fraseur (15347272) 26 April 2023 (has links)
<p> Integrating solar energy into the electric vehicle (EV) market alleviates the demand for</p>
<p>fossil fuels used to generate the electricity used to power these vehicles. Integrated solar panels</p>
<p>provide a new method of power generation for an electric vehicle, but researchers must consider</p>
<p>new dependent variables such as drag in the figure of vehicle efficiency. For the solar array to be</p>
<p>deemed a viable option for power generation, the solar array must generate enough energy to</p>
<p>overcome the added weight and aerodynamic drag forces the solar system introduces. The thesis</p>
<p>explores the application of photovoltaic modules for power generation in an EV system.</p>
<p>Researchers installed an off-the-shelf solar module on the roof of an EV and investigated the</p>
<p>system to explore the efficiency tradeoffs. The research sought to identify an optimized solar</p>
<p>panel configuration for minimized drag based on maximized panel surface irradiance, cooling,</p>
<p>and array output voltage parameters. The study utilized computational fluid dynamics modeling,</p>
<p>wind tunnel testing, and full-scale track testing to analyze the system. The results of this study</p>
<p>provide an optimized configuration for a Renogy RNG-100D atop a Chevrolet Bolt. The system</p>
<p>was considered optimal at a tilt angle of zero degrees when in motion. The performance benefits</p>
<p>due to the increased angle of the solar panel tilt were deemed insufficient in overcoming the</p>
<p>aerodynamic drag forces introduced into the system while in motion.</p>
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Quasi-Two-Dimensional Halide Perovskite Materials For Photovoltaic ApplicationsAidan Coffey (12481935) 29 April 2023 (has links)
<p>As energy demands for the world increase, the necessity for alternate sources of energy are critical. Just in the United States alone, 92 quadrillion British thermal units (Btu) were used in 2020. As political and geographical pressures surrounding oil increase, along with the growing concern for climate, the drive to explore alternative and renewable means for harvesting energy is on the rise. Solar cells, also known as photovoltaics (PVs), are an attractive renewable source and have been developed as an alternative energy means for over 60 years. When considering losses due to atmospheric absorption and scattering, the Earth’s surface gets about 1000 W/m2 of energy from the sun, which is why there are research efforts around the world trying to maximize the efficiency of solar cells.</p>
<p>Organic-inorganic halide perovskites provide for ideal absorbing layers that feature long carrier lifetime and diffusion lengths, strong photoluminescence, and promising tunability. Furthermore, the solution-processing methods used to make these perovskites ensure that the solar cells will remain low-cost and have easy scale-up possibilities. The main problem perovskites is that they degrade in the presence of water, thus leading to decreased device performance.</p>
<p>In this work two approaches are investigated to increase moisture stability. The first investigates incorporation of thiols as pseudohalides into the 2D perovskite structure. Instead of the theorized perovskite, two novel 2D compounds were created, Pb<sub>2</sub>X(S-C<sub>6</sub>H<sub>5</sub>)<sub>3</sub> (X= I, Br, Cl) and PbI<sub>1.524</sub>(S-C<sub>6</sub>H<sub>5</sub>)<sub>0.476</sub>. While not perovskites, this study gives insight into the effect that the thiol may have on determining structure when comparing –S-C<sub>6</sub>H<sub>5</sub> with –SCN groups. Future work will explore more electronegative thiols that will be used to make moisture resistant, tunable 2D perovskites.</p>
<p>The second approach is to incorporate longer organic ammonium cations into the perovskite structure to produce quasi-2D perovskite films fabricate them into devices. Adding in electronically insulating ligands leads to a stricter requirement for vertically aligned 2D films and special care must be taken to have efficient charge collection. The current field has successfully incorporated short ligands such as butylammonium (BA) into PVs, however the extension to larger and more beneficially hydrophobic ligands has been very scarce. In this work, a novel solvent engineering system is developed to create vertically aligned quasi-2D perovskite absorbing layers based off of a bithiophene ligand (2T). These absorbing layers are then characterized and incorporated into efficient PV devices. Generalizations to solvent conditions related to ligand choice is discussed herein, creating deep insights into incorporating more conjugated ligands into devices.</p>
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A Contingency Framework for Assessing the Commercial Potential of Utility-scale AgrivoltaicsLarsson, Filippa January 2023 (has links)
Purpose - In the pursuit of renewable energy sources, solar photovoltaic (PV) is predicted to become the single biggest global source of energy by the year of 2027, part of a trilemma involving climate change, biodiversity and food security. Agrivoltaic (AV) systems, the co-location and potential symbiosis between agricultural activities and solar PV, has thereby arisen as a potential solution for dual land-use. The research within this area is novel, and scholars agree that there is a need for the conceptualization of utility-scale AV in general, and the commercialization process of such systems in particular. Thereby, the purpose of this study is to unravel the key factors, activities and stakeholder involvement in order to assess the commercial potential of utility-scale AV. By addressing research questions: RQ1. What are the key factors for assessing the commercial potential of utility-scale AV?, RQ2. Which activities are essential to address these factors? and RQ3. Who are the key stakeholders that need to be involved in these activities?, a contingency framework for the assessment process has been developed. Method - In order to fulfill the purpose of this study utility-scale AV was approached as a Technology Innovation System (TIS) where the solar energy actor Sunna Group AB (Sunna) enabled insight to the potential industry context of utility-scale AV. Respondents were sampled within the TIS, forming the prerequisites for this multiple case study. Empirical data were collected in three phases: 1) Exploratory, 2) Semi-structured and 3) Final workshop, resulting in 3 workshops and 17 interviews, analyzed by a thematic analysis. Findings - The thematic analysis resulted in four main themes: 1) Socio-political factors, 2) Techno-economical factors, 3) Meso activities for commercialization and 4) Macro activities for commercialization, under which seven key factors, six overarching activities and the stakeholder involvement in these activities, were revealed. These further formed a contingency framework providing an overview of how these building blocks are interlinked. Theoretical & practical implications - The resulting framework provides an overview and synthesizes the commercialization of utility-scale AV, bridging the gap between stakeholder involvement and the key factors for assessing the commercial potential. The practical implications of this study primarily involve the solar energy sector, yet deemed to be of value to all potential stakeholders within the ecosystem of AV. Limitations & future research - The limitations of this study includes the potential exclusion of stakeholders within the data collection process due to the complex stakeholder configuration of AV, as well as the geographical constraints limiting this study to the context of Sweden. Future research is encouraged within several fields of this novel research area, predominantly including stakeholder involvement, business model configuration and how to mobilize the synergy sought in technology development between the solar energy- and agricultural sector.
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OPTIMIZATION-BASED OPERATION AND CONTROL APPROACHES FOR IMPROVING THE RESILIENCE OF ELECTRIC POWER SYSTEMSDakota James Hamilton (17048772) 27 September 2023 (has links)
<p dir="ltr">The safe and reliable delivery of electricity is critical for the functioning of our modern society. However, high-impact, low-probability (HILP) catastrophic events (such as extreme weather caused by climate change, or cyber-physical attacks) pose an ever-growing threat to the power grid. At the same time, modern advancements in computational capabilities, communication infrastructure, and measurement technologies provide opportunities for new operation and control strategies that enhance the resilience of electric power systems to such HILP events. In this work, optimization-based operation and control approaches are proposed to improve resilience in two power systems applications. First, a real-time linearized-trajectory model-predictive controller (LTMPC) is developed for ensuring voltage, frequency, and transient (rotor angle) stability in systems engineered to operate as microgrids. Such microgrids are capable of seamlessly transitioning from grid-connected operation to an islanded mode and thus, enhance system resilience. The proposed LTMPC enables rapid deployment of such systems by reducing engineering costs and development time while maintaining stable operation. On the other hand, some power systems, such as distribution feeders, are not designed to operate as standalone microgrids. For these cases, a method is proposed for forming ad-hoc microgrids from intact sections of the damaged feeder in the aftermath of a HILP event. A feeder operating center-on-a-laptop (FOCAL) is introduced that coordinates the control of possibly hundreds of inverter-interfaced distributed energy resources (e.g., rooftop solar, battery storage) to improve system resilience. Theoretical analysis as well as numerical case studies and simulations of the proposed strategies are presented for both applications.</p>
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APPLYING HEAT PIPES TO INSTALL NATURAL CONVECTION AND RADIATIVE COOLING ON CONCENTRATING PHOTOVOLTAICS.Saleh Abdullah Basamad Sr. (13163391) 28 July 2022 (has links)
<p> </p>
<p> </p>
<p>Concentrator photovoltaics have demonstrated greater solar energy production efficiency than previous solar electric technologies. However, recent research reveals that heat management is a significant difficulty in CPV systems, and if left unaddressed, it can have a severe influence on system efficiency and lifetime. Traditional CPV cooling relies on active methods such as forced air convection, or liquid cooling, which might lead to an extremely large parasitic power use. In addition, the moving parts of a cooling system result in a shorter lifespan and higher maintenance expenses. </p>
<p><br></p>
<p>CPV systems can boost their efficiency and lifespan by adopting passive cooling solutions. This work employed radiative cooling and natural convection to construct an efficient and cost-effective cooling system. The excess heat of a solar cell can be dispersed into space via electromagnetic waves via radiative cooling. Due to the fact that the radiative cooling power is related to the difference between the fourth powers of the solar cell and the ambient temperature, much greater cooling powers can be obtained at higher temperatures. Heat pipes were installed to act as a heat pump by transferring excessive heat from solar cells within a system to the exterior, where it can be dissipated via natural air cooling and thermal radiation. Experiments conducted in this study demonstrate that a temperature reduction of 21 ◦C was accomplished through radiative cooling and natural convection, resulting in an increase of 64 mV, or 17% in the open-circuit voltage of a GaSb solar cell.</p>
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DFIG-BASED SPLIT-SHAFT WIND ENERGY CONVERSION SYSTEMSRasoul Akbari (13157394) 27 July 2022 (has links)
<p>In this research, a Split-Shaft Wind Energy Conversion System (SS-WECS) is investigated</p>
<p>to improve the performance and cost of the system and reduce the wind power</p>
<p>uncertainty influences on the power grid. This system utilizes a lightweight Hydraulic Transmission</p>
<p>System (HTS) instead of the traditional gearbox and uses a Doubly-Fed Induction</p>
<p>Generator (DFIG) instead of a synchronous generator. This type of wind turbine provides</p>
<p>several benefits, including decoupling the shaft speed controls at the turbine and the generator.</p>
<p>Hence, maintaining the generator’s frequency and seeking maximum power point</p>
<p>can be accomplished independently. The frequency control relies on the mechanical torque</p>
<p>adjustment on the hydraulic motor that is coupled with the generator. This research provides</p>
<p>modeling of an SS-WECS to show its dependence on mechanical torque and a control</p>
<p>technique to realize the mechanical torque adjustments utilizing a Doubly-Fed Induction</p>
<p>Generator (DFIG). To this end, a vector control technique is employed, and the generator</p>
<p>electrical torque is controlled to adjust the frequency while the wind turbine dynamics</p>
<p>influence the system operation. The results demonstrate that the generator’s frequency is</p>
<p>maintained under any wind speed experienced at the turbine.</p>
<p>Next, to reduce the size of power converters required for controlling DFIG, this research</p>
<p>introduces a control technique that allows achieving MPPT in a narrow window of generator</p>
<p>speed in an SS-WECS. Consequently, the size of the power converters is reduced</p>
<p>significantly. The proposed configuration is investigated by analytical calculations and simulations</p>
<p>to demonstrate the reduced size of the converter and dynamic performance of the</p>
<p>power generation. Furthermore, a new configuration is proposed to eliminate the Grid-</p>
<p>Side Converter (GSC). This configuration employs only a reduced-size Rotor-Side Converter</p>
<p>(RSC) in tandem with a supercapacitor. This is accomplished by employing the hydraulic</p>
<p>transmission system (HTS) as a continuously variable and shaft decoupling transmission</p>
<p>unit. In this configuration, the speed of the DFIG is controlled by the RSC to regulate the</p>
<p>supercapacitor voltage without GSC. The proposed system is investigated and simulated in</p>
<p>MATLAB Simulink at various wind speeds to validate the results.</p>
<p>Next, to reduce the wind power uncertainty, this research introduces an SS-WECS where the system’s inertia is adjusted to store the energy. Accordingly, a flywheel is mechanically</p>
<p>coupled with the rotor of the DFIG. Employing the HTS in such a configuration allows the</p>
<p>turbine controller to track the point of maximum power (MPPT) while the generator controller</p>
<p>can adjust the generator speed. As a result, the flywheel, which is directly connected</p>
<p>to the shaft of the generator, can be charged and discharged by controlling the generator</p>
<p>speed. In this process, the flywheel energy can be used to modify the electric power generation</p>
<p>of the generator on-demand. This improves the quality of injected power to the</p>
<p>grid. Furthermore, the structure of the flywheel energy storage is simplified by removing</p>
<p>its dedicated motor/generator and the power electronics driver. Two separate supervisory</p>
<p>controllers are developed using fuzzy logic regulators to generate a real-time output power</p>
<p>reference. Furthermore, small-signal models are developed to analyze and improve the MPPT</p>
<p>controller. Extensive simulation results demonstrate the feasibility of such a system and its</p>
<p>improved quality of power generation.</p>
<p>Next, an integrated Hybrid Energy Storage System (HESS) is developed to support the</p>
<p>new DFIG excitation system in the SS-WECS. The goal is to improve the power quality</p>
<p>while significantly reducing the generator excitation power rating and component counts.</p>
<p>Therefore, the rotor excitation circuit is modified to add the storage to its DC link directly.</p>
<p>In this configuration, the output power fluctuation is attenuated solely by utilizing the RSC,</p>
<p>making it self-sufficient from the grid connection. The storage characteristics are identified</p>
<p>based on several system design parameters, including the system inertia, inverter capacity,</p>
<p>and energy storage capacity. The obtained power generation characteristics suggest an energy</p>
<p>storage system as a mix of fast-acting types and a high energy capacity with moderate</p>
<p>acting time. Then, a feedback controller is designed to maintain the charge in the storage</p>
<p>within the required limits. Additionally, an adaptive model-predictive controller is developed</p>
<p>to reduce power generation fluctuations. The proposed system is investigated and simulated</p>
<p>in MATLAB Simulink at various wind speeds to validate the results and demonstrate the</p>
<p>system’s dynamic performance. It is shown that the system’s inertia is critical to damping</p>
<p>the high-frequency oscillations of the wind power fluctuations. Then, an optimization approach</p>
<p>using the Response Surface Method (RSM) is conducted to minimize the annualized</p>
<p>cost of the Hybrid Energy Storage System (HESS); consisting of a flywheel, supercapacitor, and battery. The goal is to smooth out the output power fluctuations by the optimal</p>
<p>size of the HESS. Thus, a 1.5 MW hydraulic wind turbine is simulated, and the HESS is</p>
<p>configured and optimized. The direct connection of the flywheel allows reaching a suitable</p>
<p>level of smoothness at a reasonable cost. The proposed configuration is compared with the</p>
<p>conventional storage, and the results demonstrate that the proposed integrated HESS can</p>
<p>decrease the annualized storage cost by 71 %.</p>
<p>Finally, this research investigates the effects of the reduced-size RSC on the Low Voltage</p>
<p>Ride Through (LVRT) capabilities required from all wind turbines. One of the significant</p>
<p>achievements of an SS-WECS is the reduced size excitation circuit. The grid side converter is</p>
<p>eliminated, and the size of the rotor side converter (RSC) can be safely reduced to a fraction</p>
<p>of a full-size excitation. Therefore, this low-power-rated converter operates at low voltage</p>
<p>and handles the regular operation well. However, the fault conditions may expose conditions</p>
<p>on the converter and push it to its limits. Therefore, four different protection circuits are</p>
<p>employed, and their effects are investigated and compared to evaluate their performance.</p>
<p>These four protection circuits include the active crowbar, active crowbar along a resistorinductor</p>
<p>circuit (C-RL), series dynamic resistor (SDR), and new-bridge fault current limiter</p>
<p>(NBFCL). The wind turbine controllers are also adapted to reduce the impact of the fault</p>
<p>on the power electronic converters. One of the effective methods is to store the excess energy</p>
<p>in the generator’s rotor. Finally, the proposed LVRT strategies are simulated in MATLAB</p>
<p>Simulink to validate the results and demonstrate their effectiveness and functionality.</p>
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