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GuimarÃes, JÃssica Santos. "Wind energy conversion system connected to the grid." Universidade Federal do CearÃ, 2016. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=16813.
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Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgicoEste trabalho apresenta o desenvolvimento de um sistema de conversÃo de energia eÃlica (WECS - Wind Energy Conversion System) com gerador sÃncrono de imà permanente (PMSG - Permanent Magnet Synchronous Generator) operando com velocidade variÃvel. O circuito de processamento de energia à dividido em dois estÃgios. No estÃgio AC-DC, uma topologia boost bridgeless trifÃsica unidirecional absorve a energia fornecida pelo gerador e injeta no link DC. Neste conversor, a tÃcnica de autocontrole permite a extraÃÃo de corrente com baixa taxa de distorÃÃo harmÃnica (THD â Total Harmonic Distortion) e alto fator de potÃncia. AlÃm disso, um algoritmo de rastreamento do mÃximo ponto de potÃncia (MPPT - Maximum Power Point Tracking) determina a velocidade de rotaÃÃo do gerador que irà garantir o ponto adequado de operaÃÃo. Este modo de operaÃÃo à mantido enquanto a potÃncia disponÃvel for menor que a potÃncia nominal do conversor. Caso contrÃrio, o algoritmo de MPPT à desabilitado e uma malha de controle de potÃncia mecÃnica garante a condiÃÃo nominal de potÃncia. No estÃgio de conversÃo DC-AC, um inversor trifÃsico ponte completa, cujo controle à baseado na teoria das potÃncias instantÃneas, provà energia à rede elÃtrica cumprindo com as exigÃncias normativas. Uma anÃlise teÃrica completa à apresentada assim como os resultados de simulaÃÃo considerando o protÃtipo com a potÃncia nominal de 6 kW equivalente a turbina eÃlica utilizada. Resultados experimentais satisfatÃrios sÃo apresentados para uma potÃncia de 3 kW: o rendimento do sistema completo à superior a 90%; a corrente que circula no gerador apresenta THD de aproximadamente 2,6% e fator de potÃncia de 0,942; e a corrente injetada na rede elÃtrica possui THD de 1,639% e fator de potÃncia de 0,994.
This master thesis presents the development of a Wind Energy Conversion System (WECS) with Permanent Magnet Synchronous Generator (PMSG) operating at variable speed. The energy processing circuit is divided into two stages. In the AC-DC stage, an unidirectional three-phase bridgeless boost topology absorbs the energy supplied by the generator and injects it into the DC link. In this converter, the self-control technique allows the current extraction with low THD and high power factor. Furthermore, a - Maximum Power Point Tracking (MPPT) determines the rotational speed of the generator that will ensure the proper operating point. This mode of operation is maintained while the available power remains lower than the converter rated power. Otherwise, the MPPT algorithm is disabled and a mechanical power control loop ensures the rated power condition. On the DC-AC conversion stage, a three-phase full-bridge inverter, whose control is based on the theory of instantaneous power, provides energy to the grid complying with regulatory requirements. A complete theoretical analysis is presented as well as the simulation results considering the prototype with a rated power of 6 kW equivalent of wind turbine used. Satisfactory experimental results are shown to an output of 3 kW: the efficiency of the total system is above 90%; the current through the generator has a THD of about 2.6% with a power factor of 0.942; moreover, the current injected into the grid has a THD of about 1.639% and a power factor of 0.994.
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Dalala', Zakariya Mahmoud. "Design and Analysis of a Small-Scale Wind Energy Conversion System." Diss., Virginia Tech, 2014. http://hdl.handle.net/10919/51846.
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This dissertation aims to present detailed analysis of the small scale wind energy conversion system (WECS) design and implementation. The dissertation will focus on implementing a hardware prototype to be used for testing different control strategies applied to small scale WECSs. Novel control algorithms will be proposed to the WECS and will be verified experimentally in details.
The wind turbine aerodynamics are presented and mathematical modeling is derived which is used then to build wind simulator using motor generator (MG) set. The motor is torque controlled based on the turbine mathematical model and the generator is controlled using the power electronic conversion circuits. The power converter consists of a three phase diode bridge followed by a boost converter. The small signal modeling for the motor, generator, and power converter are presented in details to help building the needed controllers.
The main objectives of the small scale WECS controller are discussed. This dissertation focuses on two main regions of wind turbine operation: the maximum power point tracking (MPPT) region operation and the stall region operation.
In this dissertation, the concept of MPPT is investigated, and a review of the most common MPPT algorithms is presented. The advantages and disadvantaged of each method will be clearly outlined. The practical implementation limitation will be also considered. Then, a MPPT algorithm for small scale wind energy conversion systems will be proposed to solve the common drawback of the conventional methods. The proposed algorithm uses the dc current as the perturbing variable and the dc link voltage is considered as a degree of freedom that will be utilized to enhance the performance of the proposed algorithm. The algorithm detects sudden wind speed changes indirectly through the dc link voltage slope. The voltage slope is also used to enhance the tracking speed of the algorithm and to prevent the generator from stalling under rapid wind speed slow down conditions. The proposed method uses two modes of operation: A perturb and observe (PandO) mode with adaptive step size under slow wind speed fluctuation conditions, and a prediction mode employed under fast wind speed change conditions. The dc link capacitor voltage slope reflects the acceleration information of the generator which is then used to predict the next step size and direction of the current command. The proposed algorithm shows enhanced stability and fast tracking capability under both high and low rate of change wind speed conditions and is verified using a 1.5-kW prototype hardware setup.
This dissertation deals also with the WECS control design under over power and over speed conditions. The main job of the controller is to maintain MPPT while the wind speed is below rated value and to limit the electrical power and mechanical speed to be within the system ratings when the wind speed is above the rated value.
The concept of stall region and stall control is introduced and a stability analysis for the overall system is derived and presented. Various stall region control techniques are investigated and a new stall controller is proposed and implemented. Two main stall control strategies are discussed in details and implemented: the constant power stall control and the constant speed stall control.
The WECS is expected to work optimally under different wind speed conditions. The system should be designed to handle both MPPT control and stall region control at the same time. Thus, the control transition between the two modes of operation is of vital interest. In this dissertation, the light will be shed on the control transition optimization and stabilization between different operating modes.
All controllers under different wind speed conditions and the transition controller are designed to be blind to the system parameters pre knowledge and all are mechanical sensorless, which highlight the advantage and cost effectiveness of the proposed control strategy. The proposed control method is experimentally validated using the WECS prototype developed.
Finally, the proposed control strategies in different regions of operation will be successfully applied to a battery charger application, where the constraints of the wind energy battery charger control system will be analyzed and a stable and robust control law will be proposed to deal with different operating scenarios.Ph. D.
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Mondal, Abrez. "A PMSG-Based Wind Energy Conversion System Assisted by Photovoltaic Power." Thesis, North Dakota State University, 2012. https://hdl.handle.net/10365/26796.
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This work discusses a hybrid power conversion scheme consisting of a permanent magnet synchronous generator (PMSG)-based wind energy system and photovoltaic panels. The two energy sources are integrated with a battery to store extra photovoltaic energy during the day and to meet any additional power requirement in the absence of sunlight. The PV panel is interfaced to the battery through a SEPIC converter for maximum power point tracking. The wind energy from the PMSG is supplied to the battery through a boost converter which regulates the output. The total power obtained from the hybrid system is fed to a three-phase load through an inverter implementing Space-vector pulse-width modulation. The controller modeled in MATLAB/Simulink software is simple and is implemented through real time simulation using dSPACE hardware.NDSU Department of Electrical and Computer Engineering
Graduate School at North Dakota State University
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McCartney, Shauna. "The simulation and control of a grid-connected wind energy conversion system." Master's thesis, University of Central Florida, 2010. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/4680.
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With the rising cost of petroleum, concerns about exhausting the fossil fuels we depend on for energy, and the subsequent impacts that the burning of these types of fuels have on the environment, countries around the world are paying close attention to the development of renewable types of energy. Consequently, researchers have been trying to develop ways to take advantage of different types of clean and renewable energy sources. Wind energy production, in particular, has been growing at an increasingly rapid rate, and will continue to do so in the future. In fact, it has become an integral part in supplying our future energy needs, making further advancements in the field exceedingly critical. A 2 MW wind energy conversion system (WECS) is presented and has been simulated via the dynamic simulation software Simulink. This WECS consists of a 2 MW permanent magnet synchronous generator connected to the transmission grid through a power conversion scheme. The topology of this converter system consists of a passive AC/DC rectifier as well as a PWM DC/AC IGBT inverter, used to interface the DC link with the grid. The inverter has an integrated current control system for power factor correction to improve output power stability. The described WECS enhances grid-side tolerance by buffering wind power disturbances demonstrated by its capability to isolate the grid from wind speed fluctuations. It also optimizes wind energy capture through harmonic filtering, enhancing output power quality. These findings have the potential to lead to further advancements including the capability for island operation and integration to a smart grid.ID: 029050708; System requirements: World Wide Web browser and PDF reader.; Mode of access: World Wide Web.; Thesis (M.S.E.E.)--University of Central Florida, 2010.; Includes bibliographical references (p. 66-70).
M.S.E.E.
Masters
Department of Electrical Engineering and Computer Science
Engineering and Computer Science
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Fan, Shixiong. "Current source DC/DC converter based multi-terminal DC wind energy conversion system." Thesis, University of Strathclyde, 2012. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=17007.
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Wind power energy conversion is growing rapidly in the world. There are two main wind farm types, namely ac grid-based and dc grid-based wind farms. The dc grid-based approach reduces the size and weight of the magnetic components and cables. In the dc system, the step-up dc/dc converter is the key component when interfacing the wind turbine to the ac grid, via its low/medium voltage generator. This thesis focuses on the control and design of a wind energy conversion system based on dc/dc current source converters. An optimized One-Power-Point method for maximum power tracking is proposed. It incorporates One-Power-Point control and Maximum Power Differential Voltage control to allow the wind turbine to extract more energy during rapid wind speed changes. A current output hard-switched full bridge converter and serial-parallel resonant converter with an intermediate high frequency transformer are investigated for interfacing wind turbines to a local dc grid. These converters are assessed and compared in terms of semiconductor stresses and losses. A new modified One-Power-Point control method is proposed for the dc/dc converter, which tracks the maximum power during wind speed changes. A design procedure for the serial-parallel resonant converter is presented, based on its characteristics specific to a wind energy conversion system (WECS). A current source dc/dc converter based multi-terminal dc WECS is presented, investigated, and simulated. A practical multi-terminal dc WECS verifies its feasibility and stability, using two dc current output wind turbine units. Furthermore, a coordinated de-loading control scheme for the current sourcing based WECS is proposed, to cater for ac grid demand changes. It combines pitch control, dc dumping chopper control, and dc/dc converter control, to safely and quickly establish de-loading control. Both simulation and experimental results verify the de-loading scheme.
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Kendeck, Clement Ndjewel. "Fault ride-through capability of multi-pole permanent magnet synchronous generator for wind energy conversion system." Thesis, Cape Peninsula University of Technology, 2019. http://hdl.handle.net/20.500.11838/3060.
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Thesis (MEng (Electrical Engineering))--Cape Peninsula University of Technology, 2019Wind has become one of the renewable energy technologies with the fastest rate of growth. Consequently, global wind power generating capacity is also experiencing a tremendous increase. This tendency is expected to carry on as time goes by, with the continuously growing energy demand, the rise of fossil fuels costs combined to their scarcity, and most importantly pollution and climate change concerns. However, as the penetration level increases, instabilities in the power system are also more likely to occur, especially in the event of grid faults. It is therefore necessary that wind farms comply with grid code requirements in order to prevent power system from collapsing. One of these requirements is that wind generators should have fault ride-through (FRT) capability, that is the ability to not disconnect from the grid during a voltage dip. In other words, wind turbines must withstand grid faults up to certain levels and durations without completely cutting off their production. Moreover, a controlled amount of reactive power should be supplied to the grid in order to support voltage recovery at the connection point. Variable speed wind turbines are more prone to achieve the FRT requirement because of the type of generators they use and their advanced power electronics controllers. In this category, the permanent magnet synchronous generator (PMSG) concept seems to be standing out because of its numerous advantages amongst which its capability to meet FRT requirements compared to other topologies. In this thesis, a 9 MW grid connected wind farm model is developed with the aim to achieve FRT according to the South African grid code specifications. The wind farm consists of six 1.5 MW direct-driven multi-pole PMSGs wind turbines connected to the grid through a fully rated, two-level back-to-back voltage source converter. The model is developed using the Simpowersystem component of MATLAB/Simulink. To reach the FRT objectives, the grid side controller is designed in such a way that the system can inject reactive current to the grid to support voltage recovery in the event of a grid low voltage. Additionally, a braking resistor circuit is designed as a protection measure for the power converter, ensuring by the way a safe continuous operation during grid disturbance.
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Liang, Jiaqi. "Wind energy and power system interconnection, control, and operation for high penetration of wind power." Diss., Georgia Institute of Technology, 2012. http://hdl.handle.net/1853/47570.
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High penetration of wind energy requires innovations in different areas of power engineering. Methods for improving wind energy and power system interconnection, control, and operation are proposed in this dissertation. A feed-forward transient compensation control scheme is proposed to enhance the low-voltage ride-through capability of wind turbines equipped with doubly fed induction generators. Stator-voltage transient compensation terms are introduced to suppress rotor-current overshoots and torque ripples during grid faults. A dynamic stochastic optimal power flow control scheme is proposed to optimally reroute real-time active and reactive power flow in the presence of high variability and uncertainty. The performance of the proposed power flow control scheme is demonstrated in test power systems with large wind plants. A combined energy-and-reserve wind market scheme is proposed to reduce wind production uncertainty. Variable wind reserve products are created to absorb part of the wind production variation. These fast wind reserve products can then be used to regulate system frequency and improve system security.
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Stander, Johan Nico. "The specification of a small commercial wind energy conversion system for the South African Antarctic Research Base SANAE IV." Thesis, Stellenbosch : Stellenbosch University, 2008. http://hdl.handle.net/10019.1/1583.
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Thesis (MScEng (Mechanical and Mechatronic Engineering))--Stellenbosch University, 2008.The sustainability and economy of the current South African National Antarctic Expedition IV (SANAE IV) base diesel-electric power system are threatened by the current high fuel prices and the environmental pollution reduction obligations. This thesis presents the potential technical, environmental and economical challenges associated with the integration of small wind energy conversion system (WECS) with the current SANAE IV diesel fuelled power system. Criteria derived from technical, environmental and economic assessments are applied in the evaluation of eight commercially available wind turbines as to determine the most technically and economically feasible candidates. Results of the coastal Dronning Maud Land and the local Vesleskarvet cold climate assessments based on long term meteorological data and field data are presented. Field experiments were performed during the 2007-2008 austral summer. These results are applied in the generation of a wind energy resource map and in the derivation of technical wind turbine evaluation criteria. The SANAE IV energy system and the electrical grid assessments performed are based on long term fuel consumption records and 2008 logged data. Assessment results led to the identification of SANAE IV specific avoidable wind turbine grid integration issues. Furthermore, electro-technical criteria derived from these results are applied in the evaluation of the eight selected wind turbines. Conceptual wind turbine integration options and operation modes are also suggested. Wind turbine micro-siting incorporating Vesleskarvet specific climatological, environmental and technical related issues are performed. Issues focusing on wind turbine visual impact, air traffic interference and the spatial Vesleskarvet wind distribution are analysed. Three potential sites suited for the deployment of a single or, in the near future, a cluster of small wind turbines are specified. Economics of the current SANAE IV power system based on the South African economy (May 2008) are analysed. The life cycle economic impact associated with the integration of a small wind turbine with the current SANAE IV power system is quantified. Results of an economic sensitivity analysis are used to predict the performance of the proposed wind-diesel power systems. All wind turbines initially considered will recover their investment costs within 20 years and will yield desirable saving as a result of diesel fuel savings, once integrated with the SANAE IV diesel fuelled power system. Finally, results of the technical and economical evaluation of the selected commercially available wind turbines indicated that the Proven 6 kWrated, Bergey 10 kWrated and Fortis 10 kWrated wind turbines are the most robust and will yield feasible savings.
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Agabus, Hannes. "Large-scale integration of wind energy into the power system considering the uncertainty information = Elektrituulikute integreerimine energiasüsteemi arvestades informatsiooni mittetäielikkust /." Tallinn : TUT Press, 2009. http://digi.lib.ttu.ee/i/?446.
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Jones, Gavin Wesley. "Distribution system operation and planning in the presence of distributed generation technology." Diss., Rolla, Mo. : University of Missouri-Rolla, 2007. http://scholarsmine.umr.edu/thesis/pdf/Jones_09007dcc803b193d.pdf.
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Thesis (M.S.)--University of Missouri--Rolla, 2007.Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed November 16, 2007) Includes bibliographical references (p. 71-74).
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Yang, Peter Yajun. "Modeling and simulating double-output induction generator at sub-synchronous and super-synchronous speeds for wind energy conversion system." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0031/MQ65696.pdf.
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Waheed, Amna. "To Electrify a Flood Affected Village in Sajawal, Pakistan by Utilizing the Available Renewable Energy Resources." Thesis, KTH, Kraft- och värmeteknologi, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-149865.
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Pakistan, though being one of the most rich in renewable energy resources, faces serious energy crises and has a shortfall of about 6 GW electric energy. Most of the resources are untapped until today. The fuel for electricity production is being imported and is of high cost. The government is trying to fulfill the energy requirements of the industries and urban areas where rural areas are at the lowest priority. Pakistan was hit by flood disaster in 2010. There are number of organizations, governmental and private, that are trying to provide shelters and basic necessities to the flood affecties even until today. Village Goth Mehdi Farm in Sajawal area of Sindh is one of the examples of a newly built village for the flood affecties. It has been built with the help of Pakistan Navy, however, the village is bereft of electricity. This report presents three different designs for the electrification of the flood affected village, consisting of 20 houses, a mosque, a community centre, toilets and street lighting, in Sajawal, Pakistan by utilizing available renewable energy resources using sustainability approach. Supply of clean water and energy for cooking purposes was also investigated. However, it was identified in the site visit that villagers were using a mechanical hand pump to pump the underground clean water for daily usage which did not require further alternative. The village is surrounded by wheat fields and trees, and villagers used wood as fuel for cooking. Dehydrated animal dung of cattle was also used as fuel source. The Sajawal area is located in the wind corridor of Sindh and also receives sun light of high insolation level. Thus, wind turbine (WT) or/and PV module can be used for electricity generation, respectively. Based on such advantages three electricity generating systems are proposed. Option #1: solar energy by using 19 kilowatt Photovoltaic (PV) system with off grid inverter and battery bank to cater the load of the village, Option #2: wind energy by using 20 kilowatt wind turbine with a battery backup and Option #3: hybrid PV and WT system with 5.8 kilowatt PV system combine with 10 kilowatt wind turbine and battery backup. These systems have been designed by keeping social, economical and environmental aspects in account. The financial comparison showed that the option # 1 required highest amount of capital cost with respect to other options, while option # 3 needed lowest initial investment for installation. Moreover Option 1, solar system, was found to be the most expensive option when battery replacements (every 3 years) were considered over a 20 years life time. Option 3, hybrid wind and solar system, was concluded to be the most economical solution for the Goth Mehdi farms.
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Ekren, Orhan Özerdem Barış. "Optimization of a hybrid combination of a photovoltaic syste and a wind energy conversion system: İzmir Institute of technology campus area case/." [s.l.]: [s.n.], 2003. http://library.iyte.edu.tr/tezler/master/enerjimuh/T000279.rar.
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Jayam, Prabhakar Aditya. "Application of STATCOM for improved dynamic performance of wind farms in a power grid." Diss., Rolla, Mo. : Missouri University of Science and Technology, 2008. http://scholarsmine.mst.edu/thesis/pdf/Jayam_Prabhakar_09007dcc804f7428.pdf.
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Thesis (M.S.)--Missouri University of Science and Technology, 2008.Vita. The entire thesis text is included in file. Title from title screen of thesis/dissertation PDF file (viewed May 12, 2008) Includes bibliographical references (p. 64-66).
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Wang, Tian Xiang. "Study of the integration method on the control of wind power system." Thesis, University of Macau, 2009. http://umaclib3.umac.mo/record=b2144085.
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Bouwer, Pieter. "Modelling, design and implementation of a small-scale, position sensorless, variable speed wind energy conversion system incorporating DTC-SVM of a PMSG drive with RLC filter." Thesis, Stellenbosch : Stellenbosch University, 2013. http://hdl.handle.net/10019.1/80242.
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Thesis (MScEng)--Stellenbosch University, 2013.Wind energy has proven to be a viable source of clean energy, and the worldwide demand is growing rapidly. Variable speed topologies, with synchronous generators and full-scale converters, are becoming more popular, and the e ective control of these systems is a current trend in wind energy research. The purpose of this study is the modelling, design, simulation and implementation of a small-scale, variable speed wind energy conversion system, incorporating the position sensorless direct torque control with space vector modulation, of a permanent magnet synchronous generator, including an RLC converter lter. Another aim is the development of a gain scheduling algorithm that facilitates the high level control of the system. Mathematical models of the combined lter-generator model, in the stationary and rotating reference frames, are presented and discussed, from which equivalent approximate transfer functions are derived for the design of the controller gains. The design of the controller gains, RLC lter components, gain scheduling concept and maximum power point tracking controller are presented. It is discovered that the RLC lter damping resistance has a signi cant e ect on the resonance frequency of the system. The system is simulated dynamically in both Simulink and the VHDL-AMS programming language. Additionally, the maximum power point tracking controller is simulated in the VHDL-AMS simulation, including a wind turbine simulator. The simulation results demonstrate good dynamic performance, as well as the variable speed operation of the system. The practical results of torque and speed controllers show satisfactory performance, and correlate well with simulated results. The detailed gain scheduling algorithm is presented and discussed. A nal test of the complete system yields satisfactory practical results, and con rms that the objectives of this thesis have been reached.
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Liu, Xinyi. "Contribution to adaptative sliding mode, fault tolerant control and control allocation of wind turbine system." Thesis, Belfort-Montbéliard, 2016. http://www.theses.fr/2016BELF0295/document.
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Les principaux défis pour le déploiement de systèmes de conversion de l'énergie éolienne est de maximiser la puissance électrique produite, malgré les variations des conditions météorologiques, tout en minimisant les coûts de fabrication et de maintenance du système. L'efficacité de la turbine éolienne est fortement dépendante des perturbations de l'environnement et des paramètres variables du système, tels que la vitesse du vent et l'angle de tangage. Les incertitudes sur le système sont difficiles à modéliser avec précision alors qu'ils affectent sa stabilité.Afin d'assurer un état de fonctionnement optimal, malgré les perturbations, le commande adaptative peut jouer un rôle déterminant. D'autre part, la synthèse de commandes tolérantes aux défauts, capables de maintenir les éoliennes connectées au réseau après la survenance de certains défauts est indispensable pour le bon fonctionnement du réseau. Le travail de cette thèse porte sur la mise en place de lois de commande adaptatives et tolérantes aux défauts appliqués aux systèmes de conversion de l'énergie éolienne. Après un état de l'art, les contributions de la thèse sont :Dans la première partie de la thèse, un modèle incertain non linéaire du système de conversion d'énergie éolienne avec un générateur à induction à double alimentation est proposé. Une nouvelles approches de commande adaptative par mode glissant est synthétisée et ensuite appliquée pour optimiser l'énergie issue de l'éolienne.Dans la deuxième partie, une nouvelle commande par modes glissants tolérante aux défauts et basée sur les modes glissants intégrales est présentée. Puis, cette méthode est appliquée afin de forcer la vitesse de la turbine éolienne à sa valeur optimale en prenant en compte des défauts qui surviennent sur l'actionneurThe main challenges for the deployment of wind energy conversion systems (WECS) are to maximize the amount of good quality electrical power extracted from wind energy over a significantly wide range of weather conditions and minimize both manufacturing and maintenance costs. Wind turbine's efficiency is highly dependent on environmental disturbances and varying parameters for operating conditions, such as wind speed, pitch angle, tip-speed ratio, sensitive resistor and inductance. Uncertainties on the system are hard to model exactly while it affects the stability of the system. In order to ensure an optimal operating condition, with unknown perturbations, adaptive control can play an important role. On the other hand, a Fault Tolerant Control (FTC) with control allocation that is able to maintain the WECS connected after the occurrence of certain faults can avoid major economic losses. The thesis work concerns the establishment of an adaptive control and fault diagnosis and tolerant control of WECS. After a literature review, the contributions of the thesis are:In the first part of the thesis, a nonlinear uncertain model of the wind energy conversion system with a doubly fed induction generator (DFIG) is proposed. A novel Lyapunov-based adaptive Sliding Mode (HOSM) controller is designed to optimize the generated power.In the second part, a new output integral sliding mode methodology for fault tolerant control with control allocation of linear time varying systems is presented. Then, this methodology has been applied in order to force the wind turbine speed to its optimal value the presence of faults in the actuator
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Al-Quteimat, Alaa [Verfasser], Uwe [Akademischer Betreuer] Schäfer, Uwe [Gutachter] Schäfer, Sibylle [Gutachter] Dieckerhoff, and Saleh [Gutachter] Al-Jufout. "Control layout of doubly fed induction generator with respect to low voltage ride through for wind energy conversion system / Alaa Al-Quteimat ; Gutachter: Uwe Schäfer, Sibylle Dieckerhoff, Saleh Al-Jufout ; Betreuer: Uwe Schäfer." Berlin : Technische Universität Berlin, 2018. http://d-nb.info/1168324203/34.
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Gaptia, Maï Moussa Lawan. "Gestion optimale d'énergie électrique à partir des sources d'énergies renouvelables dédiées aux sites isolés Power control for decentralized energy production system based on the renewable energies — using battery to compensate the wind/load/PV power fluctuations Three level Neutral-Point-Clamped Inverter Control Strategy using SVPWM for Multi-Source System Applications Wind turbine and Batteries with Variable Speed Diesel Generator for Micro-grid Applications." Thesis, Normandie, 2019. http://www.theses.fr/2019NORMLH28.
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Les travaux de thèse s’inscrivent dans les problématiques des travaux de recherche de l’équipe thématique : Maitrise des Energies Renouvelables et systèmes de Stockage (MERS) du laboratoire GREAH-EA3220. Ils englobent le dimensionnement des éléments constitutifs du système et la gestion optimale de l’énergie électrique pour un système hybride (Diesel à vitesse variable, Eolien, PV et Batteries) dédié aux sites isolés. Les sources de production d'énergie alimentent des charges par le biais de convertisseurs multi-niveaux d’électronique de puissance. Le groupe électrogène comportant un moteur diesel à vitesse variable est considéré comme la principale source d’énergie utilisée pour contrôler la tension continue du point de couplage. Ce type de groupe électrogène est choisi pour optimiser la consommation du carburant. Il est sollicité pour délivrer une puissance électrique compatible avec le régime du moteur qui supporte mal les variations fréquentes et rapides. Les sources d’énergie renouvelables dont on cherche à augmenter la part d’énergie pour satisfaire la demande sont pilotées de manière à extraire instantanément le maximum de puissances disponible par les ressources (ensoleillement, vent). Celles-ci imposent ainsi leurs dynamiques et leurs intermittences au point de couplage. Le pack des batteries sert à compenser les fluctuations rapides de l’énergie provenant des sources d’énergie renouvelables par rapport à une évolution plus lente prise en charge par le groupe électrogène. La gestion des interactions au sein du système électrique hybride résultant est assurée au moyen de convertisseurs statiques multi-niveaux (AC / DC, DC / DC et DC / AC). Une approche de gestion d’énergie électrique fondée sur la répartition fréquentielle des perturbations induites au point de couplage par les sources renouvelables. Une plateforme expérimentale à échelle réduite (1/22) a été développée pour valider expérimentalement les approches théoriques et les simulations. Les résultats de simulations obtenus dans l’environnement logiciel Matlab/Simulink/SimPowerSystems et ceux issus du dispositif expérimental réalisé et piloté par dSPACE-1104 prouvent l’adéquation des méthodes de contrôle proposéesThe thesis works are part of the research work of the thematic team: Mastery of Renewable Energies and Storage Systems (MERS) of the GREAH-EA3220 laboratory. They include the dimensioning of the constituent elements of the system and the optimal management of electrical energy for a hybrid system (Variable speed Diesel, Wind, PV and Batteries) dedicated to isolated sites. Power sources supply loads through multi-level converters of power electronics. The generator set with a variable speed diesel engine is considered to be the main source of energy used to control the DC voltage at the coupling point. This type of generator is chosen to optimize fuel consumption. It is used to deliver an electrical power compatible with the engine speed which does not tolerate frequent and rapid variations. Renewable energy sources whose share of energy is sought to meet demand are managed so as to instantly extract the maximum power available from resources (sunshine, wind). These thus impose their dynamics and their intermittences at the coupling point. The battery pack is used to compensate for rapid fluctuations in energy from renewable energy sources compared to a slower evolution supported by the generator. Interactions within the resulting hybrid electrical system are managed by means of multi-level static converters (AC / DC, DC / DC and DC / AC). An electrical energy management approach based on the frequency distribution of disturbances induced at the coupling point by renewable sources. An experimental platform on a reduced scale (1/22) has been developed to experimentally validate theoretical approaches and simulations. The results of simulations obtained in the Matlab / Simulink / SimPowerSystems software environment and those from the experimental device produced and piloted by dSPACE-1104 prove the adequacy of the proposed control methods
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Shahbazi, Mahmoud. "Contribution à l'étude des convertisseurs statiques AC-DC-AC tolérants aux défauts." Thesis, Université de Lorraine, 2012. http://www.theses.fr/2012LORR0074/document.
Full textAbstract:
Les convertisseurs statiques triphasés AC/DC/AC à structure tension sont largement utilisés dans de nombreuses applications de puissance. La continuité de service de ces systèmes ainsi que leur sécurité, leur fiabilité et leurs performances sont aujourd'hui des préoccupations majeures de ce domaine lié à l'énergie. En effet, la défaillance du convertisseur peut conduire à la perte totale ou partielle du contrôle des courants de phase et peut donc provoquer de graves dysfonctionnements du système, voire son arrêt complet. Afin d'empêcher la propagation du défaut aux autres composants du système et assurer la continuité de service en toute circonstance lors d'une défaillance du convertisseur, des topologies de convertisseur "fault tolerant" associées à des méthodes efficaces et rapides de détection et de compensation de défaut doivent être mises en oeuvre. Dans ce mémoire, nous étudions la continuité de service de trois topologies de convertisseurs AC/DC/AC avec ou sans redondance, lors de la défaillance d'un de leurs interrupteurs. Deux applications sont ciblées : l'alimentation d'une charge RL triphasée et un système éolien de conversion de l'énergie basé sur une MADA. Un composant FPGA est utilisé pour la détection du défaut, afin de réduire autant que possible son temps de détection. Des variantes permettant d'optimiser la méthode de détection de défaut sont également proposées et évaluées. Les trois topologies de convertisseurs proposées, associées à leurs contrôleurs, ont été validées de la modélisation/ simulation à la validation sur banc de test expérimental, en passant par le prototypage "FPGA in the Loop" du FPGA, destiné plus spécifiquement à la détection du défautAC/DC/AC converters are widely being used in a variety of power applications. Continuity of service of these systems as well as their reliability and performances are now of the major concerns. Indeed, the failure of the converter can lead to the total or partial loss of the control of the phase currents and can cause serious system malfunction or shutdown. Thus, uncompensated faults can quickly endanger the system. Therefore, to prevent the spread of the fault to the other system components and to ensure continuity of service, fault tolerant converter topologies associated to quick and effective fault detection and compensation methods must be implemented. In this thesis, we present the continuity of service of three AC/DC/AC fault tolerant converters with or without redundancy, in the presence of a fault in one of their switches. Two types of applications are studied: the supply off a three-phase charge and a wind energy conversion system based on a DFIG. An FPGA based implementation is used for fault detection, in order to reduce the detection time as much as possible. Three optimizations in the fault detection method are also presented. During these researches, the three proposed converter topologies and their controllers are validated in simulations and also experimentally, while being validated in a "FPGA in the Loop" prototyping
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Croci, Lila. "Gestion de l'énergie dans un système multi-sources photovoltaïque et éolien avec stockage hybride batteries/supercondensateurs." Phd thesis, Université de Poitiers, 2013. http://tel.archives-ouvertes.fr/tel-00943296.
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Ce mémoire présente le travail de recherche effectué pour la conception d'une stratégie de commande originale, destinée aux systèmes de puissance hybrides en sites isolés. Le système considéré, voué à l'alimentation électrique d'une habitation, comprend deux sources, un groupe de panneaux photovoltaïques et une petite éolienne, et deux types de stockage, un banc de batteries lithium-ion et un de supercondensateurs. Face au problème de gestion de l'énergie dans un système hybride, et aux enjeux de maximisation de sa puissance produite, nous proposons de développer une stratégie de commande basée sur les flux d'énergie. pour cela, nous présentons dans un premier temps les modélisations d'Euler-Lagrange et hamiltonienne du système. Ces modèles permettent d'utiliser la propriété de passivité de celui-ci, et ainsi de synthétiser des commandes par injection d'amortissement pour chaque source, afin de maximiser sa production, et pour les supercondensateurs, dans le but d'assurer une répartition cohérente des flux d'énergie entre eux et les batteries. Les commandes sont finalement mises en œuvre dans un simulateur, puis dans un banc d'essai expérimental, afin d'une part de comparer leurs performances à celles de solutions préexistantes, et d'autre part de valider le bon fonctionnement du système hybride complet les utilisant.
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Δημητρακάκης, Στέφανος. "Ανάπτυξη δυναμικού μοντέλου και έλεγχος ανεμογεννήτριας συνδεδεμένης στο δίκτυο και σε αυτόνομη λειτουργία εφοδιασμένη με διάταξη αποθήκευσης ενέργειας." Thesis, 2014. http://hdl.handle.net/10889/7831.
Full textAbstract:
Η παρούσα διπλωματική εργασία πραγματεύεται τη μελέτη και τη μοντελοποίηση ενός αιολικού συστήματος παραγωγής ηλεκτρικής ενέργειας βασισμένο σε σύγχρονη γεννήτρια μόνιμου μαγνήτη (PMSG). Ειδικότερα, παρουσιάζονται και αναλύονται όλα τα τμήματα που αποτελούν το αιολικό σύστημα καθώς και οι λογικές ελέγχου που ακολουθήθηκαν για την αποτελεσματική λειτουργία του. Επιπλέον, μελετάται και μοντελοποιείται μια διάταξη αποθήκευσης ενέργειας από την οποία πλαισιώνεται το αιολικό σύστημα κατά την αυτόνομη λειτουργία του. Τέλος, παρουσιάζονται και σχολιάζονται τα αποτελέσματα της προσομοίωσης της λειτουργίας του συστήματος, σε σύνδεση με το δίκτυο και κατά την αυτόνομη λειτουργία του. Για την ανάπτυξη του μοντέλου και την προσομοίωση χρησιμοποιήθηκε το πρόγραμμα Simulink/Matlab.
Στο Κεφάλαιο 1 γίνεται αναφορά στο ενεργειακό πρόβλημα και μια γενική εισαγωγή στις ανανεώσιμες πηγές ενέργειας. Επιπλέον, δίνονται διάφορες πληροφορίες γύρω από την αιολική ενέργεια και αναλύονται τα πλεονεκτήματα και μειονεκτήματα της χρήσης ανεμογεννητριών. Επίσης, παρουσιάζεται η δομή μιας ανεμογεννήτριας και παραθέτονται διάφοροι τύποι ανεμογεννητριών, ενώ δίνονται και οι βασικές σχέσεις μετατροπής της αιολικής ενέργειας σε ηλεκτρική.
Στο Κεφάλαιο 2 γίνεται ανάλυση κάθε τμήματος της ανεμογεννήτριας (πτερωτή, σύστημα μετάδοσης κίνησης, γεννήτρια) και παρατίθενται οι εξισώσεις που περιγράφουν τη λειτουργία τους. Επιπρόσθετα, παρουσιάζεται ο τρόπος μοντελοποίησης του κάθε τμήματος στο περιβάλλον του Simulink. Ιδιαίτερη έμφαση δόθηκε στη μελέτη της σύγχρονης γεννήτριας μόνιμου μαγνήτη καθώς παρουσιάζεται με λεπτομέρεια η δομή της καθώς και οι αρχές που διέπουν τη λειτουργία της. Τέλος, δίνονται όλα τα χαρακτηριστικά μεγέθη της ανεμογεννήτρια που χρησιμοποιήθηκε στην παρούσα εργασία.
Στο Κεφάλαιο 3 αρχικά, γίνεται μια γενική παρουσίαση των στοιχείων που αποτελούν τους μετατροπείς, ενώ στη συνέχεια παρουσιάζονται οι βασικές κατηγορίες μετατροπέων που υπάρχουν και αναφέρονται μερικοί βασικοί τύποι μετατροπέων που βρίσκουν εφαρμογή σε αιολικά συστήματα γενικότερα. Έπειτα, το κεφάλαιο επικεντρώνεται στους μετατροπείς που χρησιμοποιήθηκαν στο αιολικό σύστημα της παρούσας εργασίας καθώς εξηγείται ο τρόπος λειτουργίας τους και παρουσιάζεται ο τρόπος μοντελοποίησης τους στο Simulink. Έμφαση δόθηκε στον dc/dc μετατροπέα ανύψωσης τάσης που χρησιμοποιήθηκε, όπου γίνεται διαστασιολόγηση και παρουσιάζεται μια μικρή προσομοίωση της λειτουργίας του. Τέλος, παρουσιάζεται, επίσης, το φίλτρο που τοποθετείται στην έξοδο του αντιστροφέα.
Στο Κεφάλαιο 4 περιγράφονται αναλυτικά η τεχνική διαμόρφωσης εύρους παλμών (PWM) και η τεχνική της ημιτονοειδούς διαμόρφωσης εύρους παλμών (SPWM), οι οποίες και εφαρμόστηκαν για την παλμοδότηση των μετατροπέων. Στη συνέχεια, περιγράφονται αναλυτικά οι μηχανισμοί ελέγχου που εφαρμόστηκαν με τη βοήθεια PI ελεγκτών, τόσο στην πλευρά της μηχανής (dc/dc μετατροπέας ανύψωσης τάσης) όσο και στον αντιστροφέα του αιολικού συστήματος.
Στο Κεφάλαιο 5 παρουσιάζονται και σχολιάζονται τα αποτελέσματα της προσομοίωσης του αιολικού συστήματος σε σύνδεση με το δίκτυο. Το σύστημα προσομοιώνεται για δύο περιπτώσεις, σε πρώτη φάση γίνεται προσομοίωση του συστήματος υπό σταθερή ταχύτητα ανέμου ίση με 12 m/s και σε δεύτερη φάση προσομοιώνεται η λειτουργία του συστήματος για βηματικές μεταβολές της ταχύτητας του ανέμου.
Στο Κεφάλαιο 6 μελετάται η αυτόνομη λειτουργία του αιολικού συστήματος το οποίο, πλέον, πλαισιώνεται με μια διάταξη αποθήκευσης ενέργειας. Αρχικά, παρουσιάζεται το σύστημα αποθήκευσης ενέργειας που χρησιμοποιήθηκε. Συγκεκριμένα η συστοιχία μπαταριών της οποίας δίνονται τα χαρακτηριστικά μεγέθη, καθώς και το μοντέλο της στο Simulink. Επίσης, παρουσιάζεται και μοντελοποιείται ο dc/dc μετατροπέας δύο κατευθύνσεων ο οποίος συνδέει τη συστοιχία με το υπόλοιπο σύστημα. Στη συνέχεια, περιγράφεται αναλυτικά ο μηχανισμός ελέγχου που εφαρμόζεται στη διάταξη αποθήκευσης ενέργειας για τον έλεγχο της φόρτισης/εκφόρτισης. Στο τέλος του κεφαλαίου παρουσιάζονται τα αποτελέσματα της προσομοίωσης του αυτόνομου αιολικού συστήματος για σταθερή ταχύτητα ανέμου-μεταβαλλόμενο φορτίο και για μεταβαλλόμενο άνεμο-σταθερό φορτίο.In this thesis, a wind energy conversion system (WECS) based on a permanent magnet synchronous generator (PMSG) was studied and simulated. All parts of the WECS are presented and discussed in detail. Furthermore, control strategies for the generator-side converter and the voltage source inverter are developed. The WECS is simulated both in grid connected and stand-alone mode. In the stand-alone mode, the WECS is supplied with an energy storage system for which a bi-directional buck/boost converter and control strategy was designed. Finally, simulation results are presented and performance of the system in various modes of operation is evaluated. Simulink/Matlab is used for modeling and simulating the WECS. At the beginning of Chapter 1, a discussion of energy crisis and renewable energy sources is held. Furthermore, information about wind energy has been reviewed and its benefits and drawbacks are examined. In addition, the structure of a wind turbine and the principles of converting wind energy into electricity are presented. In Chapter 2 all parts of the wind turbine are studied and its characteristics are specified. Even more, the model of every part in Simulink is presented. Theoretical background, structure and operation principles of PMSG are presented in detail. In Chapter 3, firstly a general presentation of converters components takes place. Then the major existing categories of converter are presented and some basic types of converters, which are generally used in WECS, are mentioned. Moreover, the chapter focuses on the converters that are used in this thesis, explaining the way they operate. After all, their models in Simulink are shown. Emphasis was given to the dc/dc boost converter whose parameters are calculated and its operation is simulated. Finally, there is a presentation of the filter which was placed at the output of the inverter. In Chapter 4, Pulse-width Modulation (PWM) and Sinusoidal Pulse-width Modulation (SPWM) techniques that are used in this thesis are described. Moreover, the control strategy for the generator-side converter with maximum power extraction is presented. The control strategy of the voltage sourced inverter is shown as well. In Chapter 5 simulation results of the grid connected WECS are presented and evaluated. On the first part of the presentation, the WECS is simulated for constant wind speed (12m/s), and in the second part for step-changed wind speed. In Chapter 6 the stand-alone operation of the WECS is studied and supplied with an energy storage system. Initially, there is an analysis of the energy storage system, which was used, and in particular the battery bank, whose characteristics are given. Moreover, a Bi-directional dc/dc Buck-Boost converter which is used to interconnect the battery bank to the dc-link is presented and modeled. Afterwards, there is a detailed description of the control strategy used in order to control charging / discharging of the battery bank. At the end of this chapter, simulation results of two different stand-alone operation modes are presented, one with constant wind speed and variable load and the other one with step-changing wind speed and constant load.
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Lu, Hsiang-Chun, and 路翔鈞. "Development of Wind Energy Conversion System Using Wind Turbine Simulator." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/63935490848314566362.
Full textAbstract:
碩士國立成功大學
電機工程學系碩博士班
97
This thesis presents the development of wind energy conversion system (WECS) using a wind turbine simulator. Generally, wind tunnel test is essential in the evaluation of the WECS. However, such a field test inevitably increase time and cost in the developmental process. Therefore, the proposed wind turbine simulator system is constructed to emulate the actual wind turbine characteristics. Following that, a laboratory prototype of the small scaled WECS is built. Experimental results confirm that the proposed WECS can be operated in the stand-alone loading mode or grid-connected mode at constant power output or maximum power output under the various wind speed conditions.
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Tseng, Shing-Bin, and 曾祥賓. "Study of DSP-Based Wind Power Energy Conversion System." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/46987778163921958150.
Full textAbstract:
碩士國立成功大學
電機工程學系碩博士班
91
The aim of this thesis is to research and study a wind power energy conversion system feeding an isolated load. Both output voltage and frequency of an autonomous wind generator would be inherently affected by random wind speed and the connected loads, and this thesis proposes an AC-DC-AC power converter to minimize the problems using the integration of both DSP and PWM control. Both induction generator and synchronous generator are employed as two wind power generators in order to observe and compare the characteristics and performance of the proposed energy conversion system. A 2.2 kW induction generator set, a 300 W synchronous generator set, and a TMS320F240 DSP produced by Texas Instruments are practically utilized in this thesis. Three-phase induction generator, three-phase synchronous generator, three-phase rectifier, three-phase DC-AC inverter, and DC-DC booster are integrated to form complete system dynamic equations for detailed simulation. It can be concluded from the simulated and experimental results that the practical application of the proposed wind power energy conversion system is feasible.
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Wang, Chien-Pin, and 王建斌. "Maximum Power Point Tracking Methods for Wind Energy Conversion System." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/27491473162595328286.
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碩士中原大學
電機工程研究所
93
The wind-turbine generation system (WTGS) exhibits a nonlinear characteristic and thus its maximum power point varies with changing atmospheric conditions. In order to have the WTGS operate at maximum power points under different wind speeds, the thesis proposes two maximum-power-point-tracking (MPPT) control methods of the slope-comparing (SC) and the power-difference-product (PDP) algorithms to be used in the WTGS. In the thesis, load models of the WTGS under different wind speeds are first built up for design of control rules and feasibility studies of the proposed MPPT methods. Based on the traditional current-type perturbation & observation (P&O) as well as the three-point-weighting comparison (TPWC) algorithms, comparisons are made for the proposed SC and PDP methods. In the practical system implementations, the MPPT methods are integrated in the TMS320C240 digital signal processor (DSP) to adjust the duty ratios of the buck-boost converter to control the WTGS working with maximum power output. To compare and verify the effectiveness of the four MPPT control methods mentioned above, a practical WTGS has been used. The WTGS includes a small wind turbine with three 1.17m diameter blades and a three-phase, 12-pole, 100W, small permanent-magnet synchronous generator. The experimental results show that the proposed PDP controller achieves the best performance in terms of maximum power tracking capabilities among the four MPPT algorithms, though all the four MPPT algorithms can reach maximum power points in different wind-speed conditions.
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Su, Yi Li, and 蘇益立. "A Realization of a Grid-connected Wind Energy Conversion System." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/41485223242472252474.
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碩士長庚大學
電機工程學系
98
This thesis presents a DSP microcontroller-based grid-connected wind energy conversion system (WECS). The hardware realization of the WECS consists of a 1.5kW wind driven permanent-magnet synchronous generator, (PMSG), a PWM rectifier, a push-pull converter and a grid-connected PWM inverter. The PWM rectifier, serving as a speed governor, is capable of modulating the electrical power of the PMSG such that the wind turbine (WT) can operate at optimal rotating speed and output power. The push-pull converter is mandatory to raise the PWM rectifier output voltage needed for the PWM inverter in parallel with the grid. In this thesis, a solution to mitigate the adverse transient resulted from random parallel operation of the WECS and the grid is to serve PWM inverter to provide dc-link voltage regulation irrespective to WT power generation is ongoing or not. Because the optimal power output of the wind turbine is proportional to the cube of the rotating speed, a desired power-speed curve is determined by the best energy efficiency which is recorded by the long-term power generation of the WT. The experimental results show that the proposed WECS can serve the functions of MPPT, power factor correction and reactive power compensation. Keywords: maximum power point tracking (MPPT), wind turbine driven permanent-magnet synchronous generators (PMSG), reactive power, rectifier, voltage-sourced inverter (VSI), wind energy conversion system (WECS).
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Rahimian, Mina Mashhadi. "Broken Bar Detection in Synchronous Machines Based Wind Energy Conversion System." Thesis, 2011. http://hdl.handle.net/1969.1/ETD-TAMU-2011-08-9910.
Full textAbstract:
Electrical machines are subject to different types of failures. Early detection of the incipient faults and fast maintenance may prevent costly consequences. Fault diagnosis of wind turbine is especially important because they are situated at extremely high towers and therefore inaccessible. For offshore plants, bad weather can prevent any repair actions for several weeks. In some of the new wind turbines synchronous generators are used and directly connected to the grid without the need of power converters.
Despite intensive research efforts directed at rotor fault diagnosis in induction machines, the research work pertinent to damper winding failure of synchronous machines is very limited. This dissertation is concerned with the in-depth study of damper winding failure and its traceable symptoms in different machine signals and parameters. First, a model of a synchronous machine with damper winding based on the winding function approach is presented. Next, simulation and experimental results are presented and discussed. A specially designed inside-out synchronous machine with a damper winding is employed for the experimental setup. Finally, a novel analytical method is developed to predict the behavior of the left sideband amplitude for different numbers and locations of the broken bars. This analysis is based on the magnetic field theory and the unbalanced multiphase circuits.
It is found that due to the asymmetrical structure of damper winding, the left sideband component in the stator current spectrum of the synchronous machine during steady state asynchronous operation is not similar to that of the induction machine with broken bars. As a result, the motor current signature analysis (MCSA) for detection rotor failures in the induction machine is usable to detect broken damper bars in synchronous machines. However, a novel intelligent-systems based approach is developed that can identify the severity of the damper winding failure. This approach potentially can be used in a non-invasive condition monitoring system to monitor the deterioration of a synchronous motor damper winding as the number of broken bars increase over time. Some other informative features such as speed spectrum, transient time, torque-speed curve and rotor slip are also found for damper winding diagnosis.
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Chen, Kan-Sheng, and 陳侃聲. "Optimal Capacitor and Wind Energy Conversion System Planning of Distribution Feeders." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/88780822898203342390.
Full textAbstract:
碩士南台科技大學
電機工程系
95
The objective of this thesis is to derive an optimal location and operating strategy of capacitor banks and wind energy conversion systems (WECS) installed at the distribution feeder to reduce system power loss. The objective function is formulated by including feeder peak power loss, daily energy loss and capacitor installation cost. In addition, the voltage profiles of the feeder buses and the power factors of the WECS are considered as constraints. The immune algorithm (IA) is applied to solve the optimization problem by representing the objective function and constraints as antigens. After performing the genetic evolution, an antibody which fits the antigen best is determined to be the optimal location and operating strategy of capacitor banks and WECS. The three-phase load flow analysis with considering the mutual coupling effect among conductors and load model is executed to solve system power loss on daily basis with various capacitor banks and WECS planning scenarios. To demonstrate the effectiveness of the proposed IA methodology, two practical distribution feeders in Taipower system are selected for computer simulation. It can reduce daily peak power loss and total energy loss from ask to solve the optimal installation location and operating strategy of capacitor banks and WECS. The results of the thesis can provide the analysis, planning and operating strategies for the DGS manufacturers and utilities.
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Jhang, Jhe-Wei, and 張哲瑋. "Design and Implementation of a Stand-Alone Wind Energy Conversion System." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/68191002027936509090.
Full textAbstract:
碩士國立雲林科技大學
電機工程系碩士班
99
This thesis presents a stand alone wind energy conversion system with energy storage system. The power circuits of the system are composed of the dc/dc interleaved voltage-doubler boost converter, dc/dc bi-directional buck-boost converter and the switched voltage source inverter with zero neutral point potential. The small wind generator is the main power source of the system, and the energy storage system is used for energy storage and power compensation to recover the natural irregularity of the wind energy. In order to keep wind generator produce the maximum power output, System by adjusting the bi-directional buck-boost converter switching duty cycle to achieve maximum power point tracking. A digital signal processor (TMS320LF2407A) is used for the system control that can reduce hardware components. Finally, a stand alone wind energy conversion system with output voltage 110V 60Hz and maximum output power of 600W is implemented to demonstrate the feasibility of the system.
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Tu, Chia-cheng, and 涂家政. "Design and Implementation of Power Converters for Wind Energy Conversion System." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/98368992775080277811.
Full textAbstract:
碩士國立雲林科技大學
電機工程系碩士班
97
This thesis presents the design and implementation of power converters for wind conversion systems. The power converter can not only transfer the power from wind generator, but also improve stability and safety of the system. The proposed system consists of a permanent magnet synchronous generator, a dc/dc boost converter, a bi-directional dc/dc converter and a full-bridge inverter. The wind generator is the main power source of the system, and the battery is used for energy storage and power compensation to recover the natural irregularity of the wind power. In order to keep wind power generator produce the maximum power output, a digital signal processor (TMS320LF2407A) is used to realize the system controller. Finally, a 200W wind energy conversion system is built and experimental results are provided to verify the theoretical analysis and feasibility of a wind power generator system.
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Khan, Muhammad Shahid. "Supervisory Hybrid Control of a Wind Energy Conversion and Battery Storage System." Thesis, 2008. http://hdl.handle.net/1807/11218.
Full textAbstract:
This thesis presents a supervisory hybrid controller for the automatic operation and control of a wind energy conversion and battery storage system.
The supervisory hybrid control scheme is based on a radically different approach of modeling and control design, proposed for the subject wind energy conversion and battery storage system.
The wind energy conversion unit is composed of a 360kW horizontal axis wind turbine
mechanically coupled to an induction generator through a gearbox. The assembly is electrically interfaced to the dc bus through a thyristor-controlled rectifier to enable variable speed operation of the unit. Static capacitor banks have been used to meet reactive power requirements of the
unit. A battery storage device is connected to the dc bus through a dc-dc converter to support operation of the wind energy conversion unit during islanded conditions. Islanding is assumed to occur when the tiebreaker to the utility feeder is in open position. The wind energy conversion
unit and battery storage system is interfaced to the utility grid at the point of common coupling through a 25km long, 13.8kV feeder using a voltage-sourced converter unit. A bank of static
(constant impedance) and dynamic (induction motor) loads is connected to the point of common coupling through a step down transformer.
A finite hybrid-automata based model of the wind energy conversion and storage system has
been proposed that captures the different operating regimes of the system during grid-connected and in islanded operating modes. The hybrid model of the subject system defines allowable operating states and predefines the transition paths between these operating states. A modular
control design approach has been adapted in which the wind energy conversion and storage
system has been partitioned along the dc bus into three independent system modules. Traditional control schemes using linear proportional-plus-integral compensators have been used for each system module with suitable modifications where necessary in order to achieve the required
steady state and transient performance objectives. A supervisory control layer has been used to combine and configure control schemes of the three system modules to suite the requirements of system operation during any one operating state depicted by the hybrid model of the system. Transition management strategies have been devised and implemented through the supervisory control layer to ensure smooth inter-state transitions and bumpless switching among controllers.
It has been concluded based on frequency domain linear analysis and time domain
electromagnetic transient simulations that the proposed supervisory hybrid controller is capable of operating the wind energy conversion and storage system in both grid-connected and in islanded modes under changing operating conditions including temporary faults on the utility
grid.
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Wei-ChihLiang and 梁威志. "A Three-Phase Wind Energy Conversion System with Novel Adaptive MPPT Algorithm." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/74987252756171072852.
Full textAbstract:
碩士國立成功大學
電機工程學系碩博士班
100
This thesis aims to develop a novel adaptive maximum power point tracking (MPPT) algorithm that is applied to the permanent magnet synchronous generator (PMSG) and back-to-back topology based three-phase wind energy conversion system (WECS). Topologically speaking, the MPPT algorithm can be classified into two types. One is to track the optimal power point by perturbing the electric power; the other is to reach the optimal power output by tracing the turbine power curve. Each approach has its pros and cons and they are usually the complement from one to the other. Therefore, this thesis attempts to propose a novel adaptive MPPT algorithm which keeps the merits of these two types and avoid their drawbacks. The MPPT algorithm is applied to the generator-side AC/DC converter of the three-phase WECS for controlling rotor speed of the PMSG to ensure that the wind turbine is running at optimal power output. Evaluation of the proposed MPPT algorithm is shown using the wind turbine emulator.
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Chang, YuChong, and 張育鐘. "An Implementation of Energy Conversion System by Small-Scale Hybrid Wind-Turbine." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/46559612442377121984.
Full textAbstract:
碩士明志科技大學
電機工程研究所
101
A hybrid wind-turbine generation system of single-phase 1KW is implemented with digital signal process in this paper. The control rules of maximum power point tracking, three-step charging, software phase-locked loop and hybrid islanding detection technology of grid-connected system are implemented by the software of Matlab/Simulink, which are encoded and loaded into the DSP to perform these control rules. The maximum output power of a wind-turbine would not remain at constant under various wind speed. Therefore, it must depend on a maximum power point tracking method to increase the output efficiency. The perturbation and observation method with alternating gain is used to quickly track the maximum power and effectively raise the efficiency of energy conversion. The experimental results prove that the alternating gain method is better than traditional method on the tracking speed and the stability. In the three-step charging method, the first-step uses the reflex charging strategy to retard batteries aging and increase charging energy. The second-step uses constant voltage charging strategy to prevent overcharging. If the system does not connect to the grid after finish charging, then the floating charging of third-step is performed to offset the self-discharging loss. The discrete phase-locked loop of software is used to synchronize both frequency and phase of grid voltage and full-bridge inverter output voltage prior to connect to the grid. After the system connects to the grid, the system might suffer from the risk of islanding operation. The hybrid islanding detection technology is used to prevent the event in this thesis. If the islanding operation is detected, the system would not provide nil power to the grid in order to protect the loads, inverter, and maintenance works. Keyword: Grid-Connected, Reflex Charging, Perturbation and Observation Method, Hybrid Wind-Tturbine System, Islanding Operation.
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Barakati, Seyed Masoud. "Modeling and Controller Design of a Wind Energy Conversion System Including a Matrix Converter." Thesis, 2008. http://hdl.handle.net/10012/3786.
Full textAbstract:
In this thesis, a grid-connected wind-energy converter system including a matrix converter is proposed. The matrix converter, as a power electronic converter, is used to interface the induction generator with the grid and control the wind turbine shaft speed. At a given wind velocity, the mechanical power available from a wind turbine is a function of its shaft speed. Through the matrix converter, the terminal voltage and frequency of the induction generator is controlled, based on a constant V/f strategy, to adjust the turbine shaft speed and accordingly, control the active power injected into the grid to track maximum power for all wind velocities. The power factor at the interface with the grid is also controlled by the matrix converter to either ensure purely active power injection into the grid for optimal utilization of the installed wind turbine capacity or assist in regulation of voltage at the point of connection. Furthermore, the reactive power requirements of the induction generator are satisfied by the matrix converter to avoid use of self-excitation capacitors.
The thesis addresses two dynamic models: a comprehensive dynamic model for a matrix converter and an overall dynamical model for the proposed wind turbine system.
The developed matrix converter dynamic model is valid for both steady-state and transient analyses, and includes all required functions, i.e., control of the output voltage, output frequency, and input displacement power factor. The model is in the qdo reference frame for the matrix converter input and output voltage and current fundamental components. The validity of this model is confirmed by comparing the results obtained from the developed model and a simplified fundamental-frequency equivalent circuit-based model.
In developing the overall dynamic model of the proposed wind turbine system, individual models of the mechanical aerodynamic conversion, drive train, matrix converter, and squirrel-cage induction generator are developed and combined to enable steady-state and transient simulations of the overall system. In addition, the constraint constant V/f strategy is included in the final dynamic model. The model is intended to be useful for controller design purposes.
The dynamic behavior of the model is investigated by simulating the response of the overall model to step changes in selected input variables. Moreover, a linearized model of the system is developed at a typical operating point, and stability, controllability, and observability of the system are investigated.
Two control design methods are adopted for the design of the closed-loop controller: a state-feedback controller and an output feedback controller. The state-feedback controller is designed based on the Linear Quadratic method. An observer block is used to estimate the states in the state-feedback controller. Two other controllers based on transfer-function techniques and output feedback are developed for the wind turbine system.
Finally, a maximum power point tracking method, referred to as mechanical speed-sensorless power signal feedback, is developed for the wind turbine system under study to control the matrix converter control variables in order to capture the maximum wind energy without measuring the wind velocity or the turbine shaft speed.
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Liao, Wei_Chih, and 廖偉志. "Strategies of Real Power Control for Integration of Wind Energy Conversion System to Power Grid." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/17560723872352409433.
Full textAbstract:
碩士國立成功大學
電機工程學系碩博士班
97
In recent years, wind power generation capacity has risen up gradually. When installed capacity of the wind power generation has high proportion in the grid system, the power fluctuation may impact the grid operation. The common control strategy for the wind power generation is the maximum power point tracking, which may cause the stability issue due to the variation of wind power. In order to alleviate power variation and realize the real power control, control strategies for Wind Energy Conversion System (WECS) are proposed. This thesis presents a model of PMSG-based wind energy conversion system which is equipped with energy storage system. As the WECS is operated under the maximum power point tracking, the storage system absorbs the power fluctuation from the wind. Meanwhile, the real power at grid side is still controllable when the wind speed changes. When the wind speeds are in the medium-high level, the WECS can even operate the grid side real power control without the storage system. Simulation results validate the control strategies of real power dispatch and control for the wind turbines and wind farms.
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Lin, Yu Huang, and 林育煌. "Development of a Grid-connected Wind Energy Conversion System with Power Factor Correction and Harmonic Improvement." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/01221489404937423905.
Full textAbstract:
碩士長庚大學
電機工程學系
99
The purpose of the thesis is to develop a DSP-based grid-connected wind energy conversion system (WECS), capable of compensating the power factor and current harmonic for the wind-driven generator and the grid utility. The wind power is converted to the grid through a fully digital-controlled laboratory prototype which consists of a 1.5kW wind driven permanent magnet synchronous generator (PMSG), a three-phase switching rectifier, a push-pull converter, and a grid-tied single phase inverter. The three-phase switching rectifier is used to regulate the wind turbine speed such that the wind can influence the moving blade in an efficient way without causing turbulent vortex. The push-pull converter boosts the voltage generated by the switching rectifier so as to adapt the single-phase inverter to the voltage level of the grid utility. The grid-tied single phase inverter is mandatory to maintain the dc-link voltage in order to deliver the wind power to the grid utility. To refine the power quality for the PMSG and the grid utility, additional control loops including reactive power compensator and active power filter are integrated into switching rectifier and single phase inverter. To achieve quick and accurate control in current response, a proportional-resonant (PR) current controller is adopted. The PR-controller is also advantageous to reduce the complexity in control design and the computation burden for the DSP microcontroller. The experimental results not only investigate the performance of the proposed WECS but also show that the refined power qualities such as the unity power factor, low total voltage harmonic distortion (<0.7%) and low total current harmonic distortion (<4.5%) at the grid utility fulfill the requirement stated in IEEE Std. 519.
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Yi-ChenLiu and 劉怡辰. "A MPPT Control IC Applied in Three-Phase Full-Controlled Rectifier for Wind Energy Conversion System." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/82183228523549834131.
Full textAbstract:
碩士國立成功大學
電機工程學系碩博士班
101
The design and analysis of the MPPT controller for small-scale wind energy conversion system is presented in the thesis. Different from applying a conventional boost rectifier as an AC/DC converter, this work applies the full-controlled rectifier as an AC to DC interface to achieve low current total harmonic distortion (THD) and high conversion efficiency. The low current THD in generator output can reduce the mechanical oscillation introduced by torque ripple, and high conversion efficiency can shorten the system payback period. The proposed rotational speed detection (RSD) circuit provides an elegant and accurate way to detect generator speed without the help of microprocessor or DSP which makes the system more reliable, compact and cost effective. Finally, a test rig is proposed with moment of inertia simulator to verify the performance of proposed controller more accurately. A 200W prototype is presented, and the experimental results shows the average current THD is less than 3% and with 95.2% maximum conversion efficiency. The die area is 1.107 x 1.117 mm2, and it is accomplished with TSMC 0.35m 2P4M 3.3V/5V CMOS process.
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Weng, Mao-Chung, and 翁茂鈞. "Dynamic Modeling Development of a Wind Energy Conversion System and Its Nonlinear Adaptive Feedback Controller Design." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/32201093777166287311.
Full textAbstract:
碩士長庚大學
電機工程研究所
92
This paper presents the dynamic modeling development of a wind energy conversion systems (WECS) connecting the grid. It's using Matlab/Simulink software to know the dynamic roperties during different type of wind. The system exhibited a normal operation from simulation results. Also, we design a feedback controller for the wind turbine using nonlinear and adaptive control method. Simulation results are given for verification.
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Numbi, Bubele Papy. "Optimization of reactive power flow in a wind farm-connected electric power system." 2012. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1000359.
Full textAbstract:
M. Tech. Electrical Engineering.One of the main issues in the integration of large wind power generation into the electric power networks is the voltage drop at the point of common connection (PCC) and the increase in power losses as well. This work deals with the optimization of the reactive power control in a power system with integration of a wind farm with the aim of minimizing the total active power losses and improving the load voltage profiles
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Beneke, Louis. "Development and performance investigation of a novel solar chimney power generation system." 2015. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1001691.
Full textAbstract:
D. Tech. Mechanical Engineering, Mechatronics and Industrial DesignSouth Africa has limited reserve electricity resources and many parts of the country have limited access to electricity. Electricity production capacity is at maximum and almost each Giga watt is accounted for. Predictions suggest South Africa would have a serious electricity allocation problem in the very near future and current rolling blackout in many of our cities can attest to the looming problem. The energy crisis in South Africa has highlighted the need to increase electricity generation capacity and to search for alternative energy sources. Solar chimney plants could form part of the solution in the near future in South Africa to create additional power. This study aimed to develop a wind generation system in areas where wind is absent. A solar chimney power plant is expected to provide remote areas in South Africa with electric power, or to complement the current electricity grid. Solar energy and the psychometric state of the air are important to encourage the full development of a solar chimney power plant for the thermal and electrical production of energy for various uses. Research within the South African context and particularly on increasing the effectiveness of the solar chimney power plant technology is lacking; as such this study proposes the development of a solar chimney plant and associated technology to ensure the effectiveness of this plant.
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Hamzehlouia, Sina. "MODELING AND CONTROL OF HYDRAULIC WIND ENERGY TRANSFERS." 2012. http://hdl.handle.net/1805/3365.
Full textAbstract:
Indiana University-Purdue University Indianapolis (IUPUI)The harvested energy of wind can be transferred to the generators either through a gearbox or through an intermediate medium such as hydraulic fluids. In this method, high-pressure hydraulic fluids are utilized to collect the energy of single or multiple wind turbines and transfer it to a central generation unit. In this unit, the mechanical energy of the hydraulic fluid is transformed into electric energy. The prime mover of hydraulic energy transfer unit, the wind turbine, experiences the intermittent characteristics of wind. This energy variation imposes fluctuations on generator outputs and drifts their angular velocity from desired frequencies. Nonlinearities exist in hydraulic wind power transfer and are originated from discrete elements such as check valves, proportional and directional valves, and leakage factors of hydraulic pumps and motors. A thorough understanding of hydraulic wind energy transfer system requires mathematical expression of the system. This can also be used to analyze, design, and predict the behavior of large-scale hydraulic-interconnected wind power plants. This thesis introduces the mathematical modeling and controls of the hydraulic wind energy transfer system. The obtained models of hydraulic energy transfer system are experimentally validated with the results from a prototype. This research is classified into three categories. 1) A complete mathematical model of the hydraulic energy transfer system is illustrated in both ordinary differential equations and state-space representation. 2) An experimental prototype of the energy transfer system is built and used to study the behavior of the system in different operating configurations, and 3) Controllers are designed to address the problems associated with the wind speed fluctuation and reference angular velocity tracking. The mathematical models of hydraulic energy transfer system are also validated with the simulation results from a SimHydraulics Toolbox of MATLAB/Simulink®. The models are also compared with the experimental data from the system prototype. The models provided in this thesis do consider the improved assessment of the hydraulic system operation and efficiency analysis for industrial level wind power application.
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Elnashar, Mohab. "Enabling High Wind Penetration in Electrical Grids." Thesis, 2011. http://hdl.handle.net/10012/6425.
Full textAbstract:
Wind generation has become one of the most popular choices of technology for adding new generation capacity to power systems worldwide. Several factors have contributed to the increased integration of wind generation, including environmental concerns and the continual increase in fossil fuel prices. As well, recent regulations have moved toward limitations on greenhouse gases, especially in the European Union (EU). Similar laws are currently under consideration in the US and other parts of the world. Other factors have also promoted the use of wind energy, such as advances in manufacturing and control technology and the attractiveness of wind as a “green” source of energy.
The large-scale integration of wind power into an electricity system introduces planning and operational challenges because of the intermittent nature of wind speed and the difficulty involved in predicting it. For these reasons, wind energy is often considered an unreliable energy source. Additional problems are associated with the integration of large-scale wind farms into an electrical grid, among which wind power fluctuation is the most challenging. To maximize the penetration level of wind energy in a grid, a reliable technology must be developed in order to eliminate or at least decrease wind power fluctuation.
The primary goal of this thesis was to develop methods of maximizing the penetration level of wind energy conversion systems (WECSs) into a grid, which requires mitigating wind power fluctuation. A robust control technique has therefore been developed for mitigating wind power fluctuation. This control technique exploits historical environmental data collected over a number of years in order to evaluate the profile of the output power of a variety of wind energy conversion systems (WECSs). The developed control technique was applied to Types A and C WECSs modifying the pitch angle controller of Type A WECS and the back-to-back converter control of Type C WECS. The Attachment of a storage device to the WECSs after the control technique is applied was investigated from both an economic and a technical point of view. The optimum sizing and siting of the wind energy conversion system equipped with the proposed control technique was also studied.
This research is expected to contribute to the advancement of WECS technology by presenting a feasible solution to the problems associated with the integration of large-scale WECSs into electrical grids.
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Khan, Mohammad Jahangir Alam. "Dynamic modeling, simulation and control of a small wind-fuel cell hybrid energy system for stand-alone applications /." 2004.
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Xue, Jie. "Optimal Power Control of a Wind Turbine Power Generation System." 2012. http://hdl.handle.net/1805/2981.
Full textAbstract:
Indiana University-Purdue University Indianapolis (IUPUI)This thesis focuses on optimization of wind power tracking control systems in order to capture maximum wind power for the generation system. In this work, a mathematical simulation model is developed for a variable speed wind turbine power generation system. The system consists a wind turbine with necessary transmission system, and a permanent magnet synchronous generator and its vector control system. A new fuzzy based hill climbing method for power tracking control is proposed and implemented to optimize the wind power for the system under various conditions. Two existing power tracking control methods, the tip speed ratio (TSR) control method and the speed sensorless control method are also implemented with the wind power system. The computer simulations with a 5 KW wind power generation system are performed. The results from the proposed control method are compared with those obtained using the two existing methods. It is illustrated that the proposed method generally outperforms the two existing methods, especially when the operating point is far away from the maximum point. The proposed control method also has similar stable characteristic when the operating point is close to the peak point in comparison with the existing methods. The proposed fuzzy control method is computationally efficient and can be easily implemented in real-time.