scholarly journals Introductory Chapter: Stability Control and Reliable Performance of Wind Turbines

2018 ◽  
Author(s):  
Kenneth Eloghene Okedu
Keyword(s):  
Wind Turbines ◽  
Stability Control ◽  
Reliable Performance

Linear Stability Control of Offshore Wind Turbines

2010 ◽  
Author(s):  
Christine A. Mecklenborg ◽  
Philipp Rouenhoff ◽  
Dongmei Chen
Keyword(s):  
Wind Turbines ◽  
Deep Water ◽  
Fossil Fuels ◽  
Wind Farms ◽  
Stability Control ◽  
Offshore Wind ◽  
Wave Forces ◽  
Offshore Wind Farms ◽  
Offshore Wind Turbines ◽  
Strong Winds

Offshore wind farms in deep water are becoming an attractive prospect for harnessing renewable energy and reducing dependence on fossil fuels. One area of major concern with offshore wind turbines is stability control. The same strong winds that give deep water turbines great potential for energy capture also pose a threat to stability, along with potentially strong wave forces. We examine development of state space controllers for active stabilization of a spar-buoy floating turbine. We investigate linear state feedback with a state observer and evaluate response time and disturbance rejection of decoupled SISO controllers.

scholarly journals Estimating the wake deflection downstream of a wind turbine in different atmospheric stabilities: an LES study

2016 ◽  
Vol 1 (2) ◽  
pp. 129-141 ◽  
Author(s):  
Lukas Vollmer ◽  
Gerald Steinfeld ◽  
Detlev Heinemann ◽  
Martin Kühn
Keyword(s):  
Wind Turbines ◽  
Wind Farm ◽  
Atmospheric Stability ◽  
Wind Farms ◽  
Stability Control ◽  
Energy Yield ◽  
Multiple Sources ◽  
Ambient Wind ◽  
Precise Knowledge ◽  
Temporal Averaging

Abstract. An intentional yaw misalignment of wind turbines is currently discussed as one possibility to increase the overall energy yield of wind farms. The idea behind this control is to decrease wake losses of downstream turbines by altering the wake trajectory of the controlled upwind turbines. For an application of such an operational control, precise knowledge about the inflow wind conditions, the magnitude of wake deflection by a yawed turbine and the propagation of the wake is crucial. The dependency of the wake deflection on the ambient wind conditions as well as the uncertainty of its trajectory are not sufficiently covered in current wind farm control models. In this study we analyze multiple sources that contribute to the uncertainty of the estimation of the wake deflection downstream of yawed wind turbines in different ambient wind conditions. We find that the wake shapes and the magnitude of deflection differ in the three evaluated atmospheric boundary layers of neutral, stable and unstable thermal stability. Uncertainty in the wake deflection estimation increases for smaller temporal averaging intervals. We also consider the choice of the method to define the wake center as a source of uncertainty as it modifies the result. The variance of the wake deflection estimation increases with decreasing atmospheric stability. Control of the wake position in a highly convective environment is therefore not recommended.

Development of the algorithm for the selection of a wind generator-based autonomous power supply system

2019 ◽  
Vol 2 (1) ◽  
pp. 8-16 ◽  
Author(s):  
P. A. Khlyupin ◽  
G. N. Ispulaeva
Keyword(s):  
Wind Turbines ◽  
Power Supply ◽  
Alternative Energy ◽  
Power Supply System ◽  
Supply System ◽  
Power Generators ◽  
Energy Devices ◽  
Wind Generator ◽  
Alternative Energy Sources ◽  
Selection Of

Introduction: The co-authors provide an overview of the main types of wind turbines and power generators installed into wind energy devices, as well as advanced technological solutions. The co-authors have identified the principal strengths and weaknesses of existing wind power generators, if applied as alternative energy sources. The co-authors have proven the need to develop an algorithm for the selection of a wind generator-based autonomous power supply system in the course of designing windmill farms in Russia. Methods: The co-authors have analyzed several types of wind turbines and power generators. Results and discussions: The algorithm for the selection of a wind generator-based autonomous power supply system is presented as a first approximation. Conclusion: The emerging algorithm enables designers to develop an effective wind generator-based autonomous power supply system.

Introduction: Plato’s Nightmare

2018 ◽  
Author(s):  
John Marmysz
Keyword(s):  
Immanuel Kant ◽  
Martin Heidegger ◽  
Friedrich Nietzsche ◽  
Objective Reality

This introductory chapter examines the “problem” of nihilism, beginning with its philosophical origins in the ideas of Plato, Immanuel Kant, Friedrich Nietzsche and Martin Heidegger. It is argued that film is an inherently nihilistic medium involving the evocation of illusory worlds cut loose from objective reality. This nihilism of film is distinguished from nihilism in film; the nihilistic content also present in some (but not all) movies. Criticisms of media nihilism by authors such as Thomas Hibbs and Darren Ambrose are examined. It is then argued, contrary to such critics, that cinematic nihilism is not necessarily degrading or destructive. Because the nihilism of film encourages audiences to linger in the presence of nihilism in film, cinematic nihilism potentially trains audiences to learn the positive lessons of nihilism while remaining safely detached from the sorts of dangers depicted on screen.

Introduction: Exploring Russian nationalisms

2018 ◽  
Author(s):  
Pål Kolstø ◽  
Helge Blakkisrud
Keyword(s):  
The State ◽  
Complex Interplay ◽  
Recent Developments ◽  
Part Structure

Russian societal nationalism comes in various guises, both ethnic and imperialist. Also Putin’s rhetoric is marked by the tensions between ethnic and state-focused, imperialist thinking. Noting the complex interplay of state nationalism and societal nationalism, this introductory chapter examines the mental framework within which Russian politicians were acting prior to the decision to annex Crimea. The chapter develops a typology of Russian nationalisms, surveys recent developments, and presents the three-part structure of this book: official nationalism, radical and other societal nationalisms, and identities/otherings. It concludes that after the annexation of Crimea, when the state took over the agenda of both ethnic and imperialist nationalists in Russia, societal nationalism finds itself at low ebb.

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