The thesis first provides a brief introduction to wind energy and bring in the current status of this rapidly growing industry. Further, the distribution of wind turbines, their specific and general description of the construction is described. Emphasis is placed on wind turbine control system. The first goal was to build a simulation model of wind power plant in the MATLAB / Simulink usable for subsequent overall design of control system of wind power plant. Furthermore, the analysis of the control of individual components of power station in the light of the possibility of optimizing the operation and in particular the optimization of efficiency of plant, i.e. maximization of the reached performance is performed. In the last part of this thesis structure and parameters of individual control system of plant is designed and the results are discussed.

Synchrone Messungen der Windgeschwindigkeit und die Leistung von Windkraftanlagen dienen der Ermittlung der Kennlinien der Anlagen. Die existierenden Vorschriften zur Vermessung enthalten bezüglich der Strömungseigenschaften des Windes nahezu keine Spezifikationen. Diese sind jedoch notwendig, um die erreichbare Genauigkeit und Repräsentativität der vermessenen Kennlinie zu quantifizieren. Messungen am Standort der AEOLUS II-Anlage in Wilhelmshaven dienten dazu, bei einer Anlagenvermessung die Eigenschaften der Strömung und die Kennlinie gemeinsam zu untersuchen. Es wurde gefunden, daß die Strömungseigenschaften wie die vertikale Windscherung, die Winddrehung über der Höhe, die turbulenten Schwankungen der Windgeschwindigkeit und der Windrichtung die Leistung von Windenergieanlagen bei gleicher mittlerer Windgeschwindigkeit erheblich verändern. Dabei wirken sowohl Standorteigenschaften als auch die Witterung auf die Ergebnisse der Vermessung. Am gleichen Standort können in anisotropem Gelände die Werte der Kennlinie auch bei mehrmonatigen Vermessungen wegen der Variabilität der Windrichtung Unterschiede von mehr als 10 % aufweisen. Der größte Einzeleffekt wird von der vertikalen Windscherung verursacht, die Wirkung der Drehung des mittleren Windvektors über der Rotorfläche ergab sich als kleinerer Effekt. Die Wirkung der turbulenten Schwankungen von Geschwindigkeit und Richtung weisen meist unterschiedliche Vorzeichen auf, so daß die Rolle dieser Schwankungen insgesamt meist klein bleibt. Die Vermessung einer Kennlinie mit einer kleineren systematischen Abweichung von im Mittel weniger als etwa 5 bis 10 % erfordert eine genaue Strömungsspezifikation sowohl für den Vermessungs- als für den Betriebsstandort, die bisher nicht in hinreichendem Maße in den entsprechenden Richtlinien und Vorschriften enthalten sind. / Power curves ofwind energy convetras need synchronous measurements of wind and power. The existing specification on the wind measurements are rather poor, however necessary. AEOLUS II-measurments and the wind measurments served to quantify the role of the different atmospheric parameters. Thus it was possible to define the influence on the power output of the machine as a function of the vertical wind shear, the wind veer with height, the turbulent fluctuations with the average wind speed being constant. As a consequence site properties and weather conditions both influence the measurements of the power curve. As a major result it was found that these factors may alter the power curve by as much as 10 %. The largest single effect is produced the effects of the vertical wind shear, The turbulent fluctuations are somewhat smaller in their effect, because speed and direction effects tend to compensate each other. lt may be concluded that a highly accurate power curve - meaning errors to be less than 10 % - requires a fully specified set of weather and site parameters.

Bei der Errichtung von Windenergieanlagen in Mittelgebirgsregionen ist darauf zu achten, daß an windexponierten Standorten die Gefahr einer Vereisung der Rotorblätter besteht. Es wurden klimatologische Daten im Bereich der Mittelgebirge ausgewertet und daraus eine Karte erarbeitet, in der die jährliche mittlere Häufigkeit der Tage mit Eisablagerungen dargestellt ist. / With the installation of wind turbines in low mountain areas the hazard of ice accretions on rotor blades at windy places must be considered. Interpreting climatological datas of the low mountain areas of S. E. Germany a map has been produced which shows the annual frequencies of days ice accretions on structures occurs.

Management system for enhancing transfer of knowledge in wind power industry has not received sufficient research attention in recent times. In some cases, the wind power plant owner does not control the management system for operation and maintenance activities. Most of these wind power plants are under contract and rely upon the turbine vendor to perform most of the maintenance works and subsequently share their experience at the initial stage of operation. This research investigates the management system for the operations and maintenance activities of the offshore wind plant in Lillgrund. The research also explores the type of learning method that was adopted by the wind turbine vendor (Siemens) to transfer the operation and maintenance knowledge to the operator and owner (Vattenfall) within the speculated period. It was realized that in the next one year, the Vattenfall would be in full control of the operations and maintenance activities of the offshore wind power plant in Lillgrund. The co-management arrangement will give Siemens a good reputation and gainful experience in the wind power industry. The arrangement is achievable due to Siemens strategy to strive for constructive and long-standing relationships with their customer, based on trust, respect, and honesty. Vattenfall on the other hand, is aiming to be the partner of choice for their suppliers at the same time as best serving their internal customers. The provision for the training during the co-management period enables Siemens to strengthen their relationship with Vattenfall in this industry. In addition, Siemens also maintain close relationship with their customers and develop a large part of their portfolio, frequently on site. Vattenfall improves profitability and value creation, as a fundamental prerequisite for continued growth. The management systems of Vattenfall can be related to professional bureaucracy, this is due to the fact that it was organized to accommodate Siemens experts. Vattenfall benefits from the co-management activities of the operation and maintenance of the Lillgrund wind power plant for a specific period of time. The outcome of the research work has proven that there is an effective time-dependent proportionality for a gradual transfer of the technical knowledge of operation and maintenance from Siemens Wind AB to the Vattenfall personnel. The research started from the perspective of the maintenance method by Swedish standard for wind power, and the way things are being carried out in a more practical way in Lillgrund plant.

Demand is emerging for offshore wind power plant (WPP) that often has favorable capacity factor and high capacity value as compared with onshore wind farms. There are many challenges regarding power losses, economics, protection system and reliability of the wind farm. Collection system design decisions play an essential role to efficient operation of the WPP. Wind generators also have to be able to cope with grid disturbances. Low voltage ride-through (LVRT) capability of wind turbines requires generator units remain in operation for severe voltage drops during ¡@grid system faults, and be able to withstand depressed voltage for a few seconds in a recovery period. Technical requirements set out in grid codes for off shore wind farm normally relate to different connection points. A rigor LVRT requirement would increase the overall investment costs of the wind farm. In most offshore wind farm projects, radial collector systems connecting a number of wind turbines and terminated at the offshore platform have served well the requirements for an economical design. However, due to the lack of redundancy, its reliability is poor. To improve the reliability of the collector system, the inclusion of a cable section that interconnects the remote ends of two adjacent radial feeders has been proposed. The transmission system of a wind farm takes the power generated and sends it to shore. Medium voltage AC transmission is the simplest one, just gathering the cables from the collector system and taking them together until they reach the point of common coupling (PCC).Through wind farm dynamic simulations by using DIgSIENT package, this thesis demonstrates that the ride through capability which occur at the particular wind parks with different collector system topology are greater than those which the wind turbines are capable of riding through, i.e., LVRT curves of different wind farm collection system designs of an offshore WPP and a single wind generator are different. This can be exploited to reduce the cost in complying with LVRT requirement of offshore WPP.

Rapid deployment of terrestrial wind power plants (WPPs) is a function of accurate identification of areas suitable for WPPs. Efficient WPP site prospecting not only decreases installation lead time, but also reduces site selection expenses and provides faster reductions of greenhouse gas emissions. Combining conventional predictor variables, such as wind strength and proximity to transmission lines, with nonconventional socioeconomic and demographic predictor variables, will result in improved identification of suitable counties for WPPs and therefore accelerate the site prospecting phase of wind power plant deployment. Existing and under-construction American terrestrial WPPs located in the top 12 windiest states (230 as of June 2009) plus 178 potential county level predictor variables are introduced to logistic regression with stepwise selection and a random sampling validation methodology to identify influential predictor variables. In addition to the wind resource and proximity to electricity transmission lines, existence of a Renewable Portfolio Standard, the population density within a 200 mile radius of the county center, median home values, and farm land area in the county are the four strongest nonconventional predictors (Hosmer and Lemeshow Chi-Square = 9.1250, N = 1009, df = 8, p = 0.3319, - 2LogLikelihood = 619.521). Evaluation of the final model using multiple statistics, including the Heidke skill score (0.2647), confirms overall model predictive skill. The model identifies the existence of 238 suitable counties in the twelve state region that do not possess WPPs (~73% validated overall accuracy) and eliminates 654 counties that are not classified as suitable for WPPs. The 238 counties identified by the model represent ideal counties for further exploration of WPP development and possible transmission line construction. The results of this study will therefore allow faster integration of renewable energy sources and limit climate change impacts from increasing atmospheric greenhouse gas concentrations.

Nowadays, the climate change issue is becoming more and more actual in our society. Increase of the average temperature on Earth in a couple of degrees could have catastrophic consequences. One of the possible solutions seems to be renewable energy sources as photovoltaics, biomass of water and wind energy. This thesis deals with the aerodynamics problems of wind energy source. Wind turbines transform kinetic energy of wind to mechanical power. The efficiency is physically limited to 59,26 %, but in reality, it is getting around 45 %. This is caused by three biggest losses inducted in wind turbines as wake losses, losses due to finite number of blades and drag losses. Based on analytical relationships and including these three losses the aerodynamics blade design is conducted. Later, the numerical simulations show higher values of drag and lower values of lift force on airfoil compared to analytical calculation. In fact, percentage deviations are acceptable and to conclude, the numerical analysis was able to relatively accurately simulate force action of free stream velocity on the blade.

The aim of this paper is to acquaint the readers with basic classification of wind turbine configuration by used electric generator, with speed and power control used in power plants and with mathematical model of wind and parts of power plant. Procedure of making model in applications Mathematica and MathModelica is described in the other part of this paper. There were made models of power plants with squirrel cage asynchronous generator, one with pitch control, the other with stall control. In the last part of the thesis comparison of model behavior of both models with the same input conditions was made.

This Master´s thesis deals with problematics of wind powered generators and their use in off-grid systems. In its first chapters aspects of wind as a power source are analyzed. Further on the thesis focuses on individual components of the off-grid systems. Also designing procedures of these systems are presented in the paper. The key parts of the thesis are 3 off-grid wind power system designs, which can be used to power a family house, and their energetical and economical evaluation.

This master thesis deals with problematic wind power plants. There are described advantages and disadvantages of wind power plants and their environmental impacts. Thesis include chosen locality for wind power plant, chosen fitting types of turbines and calculation which choosing turbine for chosen locality. There are accomplished parametric studies of main parameters. From this study is chosen best fitting model of wind turbine. In the end are adduced statistics from Czech Republic, Europe and world.