Indiana University-Purdue University Indianapolis (IUPUI) / In this research, a Split-Shaft Wind Energy Conversion System (SS-WECS) is investigated to improve the performance and cost of the system and reduce the wind power uncertainty influences on the power grid. This system utilizes a lightweight Hydraulic Transmission System (HTS) instead of the traditional gearbox and uses a Doubly-Fed Induction Generator (DFIG) instead of a synchronous generator. This type of wind turbine provides several benefits, including decoupling the shaft speed controls at the turbine and the generator. Hence, maintaining the generator’s frequency and seeking maximum power point can be accomplished independently. The frequency control relies on the mechanical torque adjustment on the hydraulic motor that is coupled with the generator. This research provides modeling of an SS-WECS to show its dependence on mechanical torque and a control technique to realize the mechanical torque adjustments utilizing a Doubly-Fed Induction Generator (DFIG). To this end, a vector control technique is employed, and the generator electrical torque is controlled to adjust the frequency while the wind turbine dynamics influence the system operation. The results demonstrate that the generator’s frequency is maintained under any wind speed experienced at the turbine. Next, to reduce the size of power converters required for controlling DFIG, this research introduces a control technique that allows achieving MPPT in a narrow window of generator speed in an SS-WECS. Consequently, the size of the power converters is reduced significantly. The proposed configuration is investigated by analytical calculations and simulations to demonstrate the reduced size of the converter and dynamic performance of the power generation. Furthermore, a new configuration is proposed to eliminate the Grid- Side Converter (GSC). This configuration employs only a reduced-size Rotor-Side Converter (RSC) in tandem with a supercapacitor. This is accomplished by employing the hydraulic transmission system (HTS) as a continuously variable and shaft decoupling transmission unit. In this configuration, the speed of the DFIG is controlled by the RSC to regulate the supercapacitor voltage without GSC. The proposed system is investigated and simulated in MATLAB Simulink at various wind speeds to validate the results. 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 coupled with the rotor of the DFIG. Employing the HTS in such a configuration allows the turbine controller to track the point of maximum power (MPPT) while the generator controller can adjust the generator speed. As a result, the flywheel, which is directly connected to the shaft of the generator, can be charged and discharged by controlling the generator speed. In this process, the flywheel energy can be used to modify the electric power generation of the generator on-demand. This improves the quality of injected power to the grid. Furthermore, the structure of the flywheel energy storage is simplified by removing its dedicated motor/generator and the power electronics driver. Two separate supervisory controllers are developed using fuzzy logic regulators to generate a real-time output power reference. Furthermore, small-signal models are developed to analyze and improve the MPPT controller. Extensive simulation results demonstrate the feasibility of such a system and its improved quality of power generation. Next, an integrated Hybrid Energy Storage System (HESS) is developed to support the new DFIG excitation system in the SS-WECS. The goal is to improve the power quality while significantly reducing the generator excitation power rating and component counts. Therefore, the rotor excitation circuit is modified to add the storage to its DC link directly. In this configuration, the output power fluctuation is attenuated solely by utilizing the RSC, making it self-sufficient from the grid connection. The storage characteristics are identified based on several system design parameters, including the system inertia, inverter capacity, and energy storage capacity. The obtained power generation characteristics suggest an energy storage system as a mix of fast-acting types and a high energy capacity with moderate acting time. Then, a feedback controller is designed to maintain the charge in the storage within the required limits. Additionally, an adaptive model-predictive controller is developed to reduce power generation fluctuations. The proposed system is investigated and simulated in MATLAB Simulink at various wind speeds to validate the results and demonstrate the system’s dynamic performance. It is shown that the system’s inertia is critical to damping the high-frequency oscillations of the wind power fluctuations. Then, an optimization approach using the Response Surface Method (RSM) is conducted to minimize the annualized 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 size of the HESS. Thus, a 1.5 MW hydraulic wind turbine is simulated, and the HESS is configured and optimized. The direct connection of the flywheel allows reaching a suitable level of smoothness at a reasonable cost. The proposed configuration is compared with the conventional storage, and the results demonstrate that the proposed integrated HESS can decrease the annualized storage cost by 71 %. Finally, this research investigates the effects of the reduced-size RSC on the Low Voltage Ride Through (LVRT) capabilities required from all wind turbines. One of the significant achievements of an SS-WECS is the reduced size excitation circuit. The grid side converter is eliminated, and the size of the rotor side converter (RSC) can be safely reduced to a fraction of a full-size excitation. Therefore, this low-power-rated converter operates at low voltage and handles the regular operation well. However, the fault conditions may expose conditions on the converter and push it to its limits. Therefore, four different protection circuits are employed, and their effects are investigated and compared to evaluate their performance. These four protection circuits include the active crowbar, active crowbar along a resistorinductor circuit (C-RL), series dynamic resistor (SDR), and new-bridge fault current limiter (NBFCL). The wind turbine controllers are also adapted to reduce the impact of the fault on the power electronic converters. One of the effective methods is to store the excess energy in the generator’s rotor. Finally, the proposed LVRT strategies are simulated in MATLAB Simulink to validate the results and demonstrate their effectiveness and functionality.

The electric power system is designed to economically and reliably transmit electricity to homes, industry, and businesses. The economic impact of the electric grid was demonstrated by the 2003 blackout's visible impact in the graph of the yearly gross domestic product of the Unites States. However, because the number of customers is so large and economies of scale are leveraged to keep electricity prices low, utilities are strongly interconnected. Performing comprehensive engineering analyses to ensure reliable operation is still impossible. Instead, heuristics and safety factors are incorporated into planning processes to continually meet demand in a way that complies with Federal regulations. As evidenced by the infrequency of blackouts in the United States, the sophisticated planning processes have up to date been relatively successful. However, the power system is constantly changing. Electrical generators based on renewable energies are a beneficial addition to the grid, but these and other technological changes like high-voltage power electronic converters also come with their own challenges. These systems as currently employed tend to have a different impact on the reliability of operation than traditional fossil fuel based generators. As the system changes, so do the engineering analyses required to ensure reliable operation. In particular, the wind energy conversion systems (WECS) negatively impact the response of the grid to disturbances in certain ways due to inherent challenges harnessing the wind as an energy sources. These negative impacts (and the advent of powerful personal computing) require an increase in the sophistication of power system models. Thus, there are competing challenges: the scale of the power system necessitates computationally efficient modeling, but the complexity of analysis required to maintain reliable operation is also increasing. The primary aim of this study is to develop models and methods for more detailed yet computationally manageable simulation. To this aim, higher order linearizations and the properties of linear systems (graph theory and linear algebra) are exploited. More specifically, this document contains three studies. In the short term planning and situational awareness context, a method is proposed to quickly check credible outages of important grid equipment. This methodology enables the inspection of a wider breadth of system conditions to ameliorate the negative impacts of the unpredictability of the wind. A linear model in the traditional sense is also developed to model any arbitrary number of wind turbines in a wind farm. This enables industry players to study the impacts wind turbine interaction on the dynamic stability of the grid in response to small disturbances. Finally, a wind farm is modeled as a large matrix to model even nonlinear behavior of wind farms. This helps industry players analyze the impact of large disturbances on the grid. / Doctor of Philosophy / The electric power system is designed to economically and reliably transmit electricity to homes, industry, and businesses. The economic impact of the electric grid was demonstrated by the 2003 blackout’s visible impact in the graph of the yearly gross domestic product of the United States. However, because the number of customers is so large and economies of scale are leveraged to keep electricity prices low, utilities are strongly interconnected. Performing comprehensive engineering analyses to ensure reliable operation is still impossible. Instead, heuristics and safety factors are incorporated into planning processes to continually meet demand in a way that complies with Federal regulations. As evidenced by the infrequency of blackouts in the United States, the sophisticated planning processes have up to date been relatively successful. However, the power system is constantly changing. Electrical generators based on renewable energies are a beneficial addition to the grid, but these and other technological changes like high-voltage power electronic converters also come with their own challenges. These systems as currently employed tend to have a different impact on the reliability of operation than traditional fossil fuel based generators. As the system changes, so do the engineering analyses required to ensure reliable operation. In particular, the wind energy conversion systems (WECS) negatively impact the response of the grid to disturbances in certain ways due to inherent challenges harnessing the wind as an energy sources. These negative impacts (and the advent of powerful personal computing) require an increase in the sophistication of power system models. Thus, there are competing challenges: the scale of the power system necessitates computationally efficient modeling, but the complexity of analysis required to maintain reliable operation is also increasing. The primary aim of this study is to develop models and methods for more detailed yet computationally manageable simulation. To this aim, higher order linearizations and the properties of linear systems (graph theory and linear algebra) are exploited. More specifically, this document contains three studies. In the short term planning and situational awareness context, a method is proposed to quickly check credible outages of important grid equipment. This methodology enables the inspection of a wider breadth of system conditions to ameliorate the negative impacts of the unpredictability of the wind. A linear model in the traditional sense is also developed to model any arbitrary number of wind turbines in a wind farm. This enables industry players to study the impacts wind turbine interaction on the dynamic stability of the grid in response to small disturbances. Finally, a wind farm is modeled as a large matrix to model even nonlinear behavior of wind farms. This helps industry players analyze the impact of large disturbances on the grid.

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.

Globally, wind power is leading the renewable energy revolution. While carbon neutral and cost-effective, wind energy infrastructure is immobile and has the potential to profoundly change land use and the visible landscape. As wind technology takes its place as a key contributor to the US energy grid, it becomes clear that these types of projects will come into greater contact with areas occupied by humans, and eventually with wilderness and other more natural areas. This increased visibility and close proximity necessitates the development of future wind farm sites that afford opportunities for auxiliary uses while maintaining their intrinsic value as energy producers. In short, it is important for wind farms to be versatile because land is a finite resource and because over time, increasing numbers of these sites will occupy our landscapes. In the Eastern US, the majority of onshore wind resources suitable for energy development are found along ridge lines in the Appalachian mountains. These mountains are ancient focal points in the landscape, and subsequently host myriad sites of historic, recreational, and scenic significance. In the future, these windswept ridges will likely become targets for wind energy development. This thesis demonstrates a methodology for the thoughtful siting and design of future wind projects in the Appalachian mountains. Opportunities for offsite views, diversified trail experiences, and planned timber harvests are realized by locating a seven-turbine wind park adjacent to the Appalachian Trail in Cherokee National Forest in Carter county, Tennessee. The proposed wind park demonstrates the sound possibility of thoughtfully integrating wind infrastructure along Appalachian ridges in conjunction with forestry and recreation opportunities, such as hiking and camping. The design is a wind park rather than a wind farm because in addition to its inherent function as a production landscape, it is also a place that is open to the general public for recreational use. / Master of Landscape Architecture / Wind power is among the fastest-growing renewable energy resources on the planet. While clean and cost-effective, wind turbines are immobile in the landscape and require large areas of land in order to function properly. Due to the vertical nature of wind turbines, much of the land within wind project boundaries is left unused. As more wind farms are built, they will begin to come into greater contact with areas where humans live and also with more natural areas. In order for this growth to occur responsibly, future wind farm sites should be planned to take advantage of the leftover ground within their boundaries. Incorporating other types of use into wind projects is important because unlike the wind, land is not an unlimited resource. On-shore in the Eastern U.S., the windiest places are the ridge lines in the Appalachian Mountains. In the future these mountains could become targets for wind energy development, which is problematic because they are significant for their environmental, cultural, and recreational values. This thesis provides a method for the thoughtful siting and design of future wind farms in the Appalachian mountains by locating a seven-turbine wind park next to the Appalachian Trail in Carter County, Tennessee. The design shows that it is possible to thoughtfully combine wind energy with other uses like forestry, natural resource conservation, and various types of recreation along Appalachian ridges. The design is a wind park rather than a wind farm because in addition to its basic function as a production facility, it is also a place that is open to the general public for recreational use.

Yes / The fast‐growing offshore wind energy sector brings opportunities to provide a sustainable energy resource but also challenges in offshore wind turbine (OWT) operation and maintenance management. Existing operational simulation models assume deterministic input reliability and failure cost data, whereas OWT reliability and failure costs vary depending on several factors, and it is often not possible to specify them with certainty. This paper focuses on modelling reliability and failure cost uncertainties and their impacts on OWT operational and economic performance. First, we present a probabilistic method for modelling reliability data uncertainty with a quantitative parameter estimation from available reliability data resources. Then, failure cost uncertainty is modelled using fuzzy logic that relates a component's failure cost to its capital cost and downtime. A time‐sequential Monte Carlo simulation is presented to simulate operational sequences of OWT components. This operation profile is later fed into a fuzzy cost assessment and coupled with a wind power curve model to evaluate OWT availability, energy production, operational expenditures and levelised cost of energy. A case study with different sets of reliability data is presented, and the results show that impacts of uncertainty on OWT performance are magnified in databases with low components' reliability. In addition, both reliability and cost uncertainties can contribute to more than 10% of the cost of energy variation. This research can provide practitioners with methods to handle data uncertainties in reliability and operational simulation of OWTs and help them to quantify the variability and dependence of wind power performance on data uncertainties. / Engineering and Physical Sciences Research Council. Grant Number: EP/P009743/1

This paper aims to investigate some of the diverse perceptions of local populations in Sweden regarding wind energy, focusing on the Ockelbo area. Through a critical discourse analytical perspective, the analysis explores the community's attitudes toward their role in wind energy development and analyzes the presence of discursive elements. The study uses mostly interviews and shows that the local community generally supports wind energy. In contrast to many other areas, the Ockelbo area does not seem to have the individual gap of the Nimby attitude, whereby individuals have a positive attitude toward wind energy in general and a negative attitude toward wind energy in their nearby area. Instead, my informants are generally positive toward wind energy both in general and in Ockelbo. Furthermore, I have related my findings to the theory of environmentality, in which the responsibility for the environment is placed on the population rather than the state through knowledge production about the climate. I argue that elements of environmentality are present in the Ockelbo area through a climate IDF (discursive-ideological formation). This climate IDF frames fossil-free energy as a necessary measure against climate change, that the local population should feel responsible for accepting. This perceived responsibility can be attributed to government rationalities of the state. However, my material shows that the local community does not completely accept responsibility for allowing wind energy. Instead, most of my informants seem to discuss how different aspects of wind energy, such as economic compensation for it, conditions their acceptance for wind energy. Therefore, I do not think that the informants – and perhaps the Ockelbo community in general – are fully internalizing the state’s prioritization of wind energy in areas such as that of Ockelbo.

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.

Thesis (MBA (Business Management))--Stellenbosch University, 2008. / ENGLISH ABSTRACT: With the introduction of Section 17 of the EnWG (German Energy Economy Act), the legislator created a new situation for the complex relationships in the German offshore wind industry. The transmission system operators are now obliged not only to provide the connection for offshore wind farms, but also to reimburse the developers of such plants for the costs they incurred in the course of planning the cable connection between the wind farm and the onshore grid. Forecasts had predicted that by 2007 numerous offshore wind farms would be operational. But no development company in the entire sector had moved beyond the planning phase. However, the rapid development of the offshore wind industry is important in order to achieve the German goal to generate 20% of all energy from renewable energy sources by 2020 and thus contribute to the prevention of grave climate changes. It is also important for the domestic labour market and the initiation of further exports of energy technologies. Early domestic growth will eventually payoff as offshore wind energy is implemented by more countries, which will then rely on the experience of German companies. Under these circumstances, Section 17 (2a) S.3 of the EnWG induces a positive impulse for offshore development. Under the financial constraints that dampened the expectations of developers of offshore wind farms, the suggested reimbursement will offer welcome relief. However a broad interpretation of Section 17 (2a) S.3 of the EnWG must be applied in order to reach the goal of actually enhancing offshore development, as is the legislator's intent. Such a broad interpretation of the reimbursement claim will lead to rapid implementation of the new law, as this will be in the interest of the developers and transmission system operators. The developers will have a large interest in beginning with the actual construction of the wind farm, and the transmission system operators will need to proceed with the planning of the cable connection. Even though improvements remain necessary the introduction of Section 17 (2a) S.3 EnWG can be considered a success. / AFRIKAANSE OPSOMMING: Met die inwerkingstelling van afdeling 17 van die EnGW (Duitse Energie Ekonomie Wet), het die regering 'n nuwe situasie geskep vir die komplekse verhouding in die Duitse see-gebonde wind-energie industrie. Die transmissie stelsel operateurs word nou verplig om nie net die verbinding met die wind-plaas te verskaf nie, maar moet ook die ontwikkelaar van die aanleg vergoed vir enige kostes wat hulle aangegaan het met die beplanning van die verbinding tussen die windplaas en die elektrisiteits-netwerk. Vooruitskattings het voorspel dat verskeie see-gebonde windplase operasioneel sou wees teen 2007. Geen ontwikkelingsmaatskappy het egter al tot dusver verder as die beplanningstadium gevorder nie. Desnieteenstaande, die spoedige ontwikkeling van die see-gebonde wind industrie is onontbeerlik in die Duitse mikpunt om 20% van energiebehoeftes op te wek vanuit hernubare bronne teen 2020 en om dus klimaatsverandering teen te werk. Dit is ook belangrik vir werkskepping in Duitsland en vir die uitvoer van energie tegnologie. Spoedige groei in die industrie sal uiteindelik dividende lewer soos seegebonde wind-energie deur ander lande ontwikkel word en gevolglik op Duitse ervaring moet staatmaak. Onder hierdie omstandighede het afdeling 17 (2a) 5.3 van die EnGW 'n positiewe effek op seegebonde ontwikkeling. As gevolg van die dempende effek wat finansiele beperkinge het op die verwagtinge van ontwikkelaars sal die terugbetalings welkome verligting bied. Dit is egter nodig om 'n bree interpretasie van afdeling 17 (2a) 5.3 van die EnGW te gebruik om die mikpunt van werklike bevordering van seegebonde ontwikkeling te bewerkstellig soos die wetgewer beoog. So 'n bree interpretasie sal lei tot spoedige implimentasie van die nuwe wet omdat dit in die belang van ontwikkelaars en transmissie-netwerk eienaars sal wees. Die ontwikkelaars sal baat daarby om spoedig met ontwikkeling te begin, terwyl die netwerk operateurs vordering sal moet maak met die beplanning van die kabel-verbinding. Ten spyte daarvan dat verdere verbeteringe nodig is kan die inwerkingstelling van afdeling 17 (2a) 5.3 van die EnGW as 'n sukses gereken word.

Made available in DSpace on 2017-07-10T17:11:51Z (GMT). No. of bitstreams: 1 MARCOS GUILHERME ZANCHETTIN.pdf: 1368217 bytes, checksum: 2ad7e15a270a9abefc8d6f85f3ba01e0 (MD5) Previous issue date: 2012-04-25 / The wind generation has stood out among the alternative sources and has experienced a high rate of penetration through the years. Thus, the electrical connection of wind power generation must be analyzed in detail to avoid or minimize the problems inherent this type of source can cause in electric power systems (SEP) and thereby preserve the voltage quality indicators and reliability. This paper deal about the integration of wind farms in SEP, equipped with squirrel-cage induction generator based fixed speed wind turbines (AVV-SCIG) and doublyfed induction generator based variable speed wind turbines (AVV-DFIG). The limits of integration of wind energy generation, i.e., the amount of power that the wind farm can provide the point-of-common-connection (PCC) while complying with certain interconnections requirements, are obtained considering static and transient aspects of the connection of wind farms. The topology adopted to represent, in a simplified way, the local characteristics of the connection between the wind farm and the SEP, as well as characterize the integration of wind generation from the parameters of the PCC, is the single machine infinite-bus system (MBI). Throughout the text also are presents the models used to represent the wind turbine and wind farm in studies of power systems, the main criteria specified to connection of this type of source in SEP and the main issues dealing with the problem of integration of generation wind. The analyzes aim to assess how the wind energy generation is impacted by technical criteria that consider static and transient aspects of the connection of wind farms, the technology used in energy conversion, the control strategy/operation and the characteristics of PCC. The results obtained allow to define which the stricts conditions for the integration of wind energy generation. For these analyzes are considered the criteria of the maximum allowable voltage variation at the connection point of the wind farm, the power range for the maximum transferable power to the electrical system and the fault ride through capability. / A geração eólica vem se destacando entre as fontes alternativas e tem experimentado um elevado índice de pene- tração ao longo dos anos. Assim, a conexão elétrica de parques eólicos precisa ser analisada detalhadamente a fim de evitar ou minimizar os efeitos que os problemas inerentes desse tipo de fonte, geração eólica, podem causar em sistemas elétrico de potência (SEP) e com isso preservar os indicadores de qualidade de tensão e confiabilidade. Este trabalho trata da integração de centrais eólicas em SEP, equipadas com aerogeradores de velocidade fixa com gerador de indução de rotor em gaiola (AVF-SCIG) e aerogeradores de velocidade variável com gerador de indução duplamente alimentado (AVV-DFIG). Os limites de inserção de geração eólica, i.e., a quantidade de potência que o parque eólico pode fornecer ao ponto comum de conexão (PCC) tendo que atender certos critérios da integração, são obtidos considerando aspectos estáticos e transitórios da conexão de centrais eólicas. A topologia adotada para representar, de maneira simplificada, as características locais de conexão entre o parque eólico e o SEP, assim como caracterizar a inserção de geração eólica a partir dos parâmetros do PCC, é o modelo máquina barra-infinita (MBI). Ao longo do texto também são apresentados os modelos empregados para representar tanto o aerogerador quanto o parque eólico em estudos de sistemas de potência, os principais critérios especificados para a conexão desse tipo de fonte em SEP e as principais questões que tratam do problema de inserção de geração eólica. As análises têm por objetivo avaliar como a inserção de geração eólica é impactada por critérios técnicos que consideram aspectos estáticos e transitórios da conexão de centrais eólicas, pela tecnologia empregada na conversão de energia, pela estratégia de controle/operação e pelas características do PCC. Os resultados obtidos permitem definir quais as condições mais severas à inserção de geração eólica. Para estas análises são considerados os critérios da máxima variação de tensão admissível no ponto de conexão da central eólica, a margem de potência relativamente à máxima potência transferível ao sistema elétrico e a capacidade de sustentação durante faltas.

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.