Sökning: "Wind turbines"

Visar resultat 1 - 5 av 155 avhandlingar innehållade orden Wind turbines.

  1. 1. Wind-wave interaction effects on offshore wind energy

    Författare :Ali Al Sam; Strömningsteknik; []
    Nyckelord :wind-wave; swell; atmospheric boundary layer; marine atmospheric boundary layer; atmospheric turbulence; Large-eddy simulation; actuator line; wind sea; offshore technology; wind energy; wind turbine; aerodynamic;

    Sammanfattning : This thesis is devoted to the investigation of the impacts of fast moving ocean surface waves on the aerodynamics of offshore wind turbines. The impacts of non-locally generated waves (swell) on the Marine Atmospheric BoundaryLayer (MABL) and thereby on offshore wind turbine aerodynamics are studied numerically by using Large Eddy Simulations and the Actuator Line Method. LÄS MER

  2. 2. Fault Behavior of Wind Turbines

    Författare :Francesco Sulla; Industriell elektroteknik och automation; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Wind Turbines; Short-Circuit Currents; Doubly-Fed Induction Generator; Grid Fault Ride-Through; Voltage Support; Weak Grid;

    Sammanfattning : Synchronous generators have always been the dominant generation type in the grid. This fact affected both planning and operation of power systems. With the fast increase of wind power share in the grid in the last decade, the situation is changing. In some countries wind power represents already a consistent amount of the total generation. LÄS MER

  3. 3. The Power Qualities of Wind Turbines

    Författare :Åke Larsson; Chalmers University of Technology; []
    Nyckelord :wind turbines; power quality; frequency variations; flicker; measurements;

    Sammanfattning : The power quality of wind turbines is dealt with in this dissertation. The thesis consists of four parts. The first part describes the electrical systems used in wind turbines. The second part presents the results of measurements of different types of wind turbines connected to different types of grids. LÄS MER

  4. 4. Numerical Computations of Wakes Behind Wind Farms

    Författare :Ola Eriksson; Stefan Ivanell; Simon-Philippe Breton; Anna Rutgersson; Dan Henningson; Niels Troldborg; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Wind turbine; Wind power; Wind farm; Wakes; Long distance wakes; Farm-Farm; Farm to farm interaction; Wind farm cluster; Large Eddy simulations; LES; Actuator disc method; ACD; CFD; Ellipsys3D;

    Sammanfattning : More and larger wind farms are planned offshore. As the most suitable build sites are limited wind farms will be constructed near to each other in so called wind farm clusters. Behind the wind turbines in these farms there is a disrupted flow of air called a wake that is characterized by reduced wind speed and increased turbulence. LÄS MER

  5. 5. Numerical Computations of Wakes Behind Wind Farms : A tool to study Farm to Farm interaction

    Författare :Ola Eriksson; Stefan Ivanell; Anna Rutgersson; Simon-Philippe Breton; Philippe Chatelain; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; Wind turbine; Wind power; Wind farm; Wakes; Long distance wakes; Farm-Farm; Farm to farm interaction; Wind farm cluster; Large Eddy simulations; LES; Actuator disc method; ACD; CFD; Ellipsys3D; Prescribed boundary layer; PBL; Forced boundary layer; FBL; Meteorologi; Meteorology;

    Sammanfattning : More and larger wind farms are planned offshore. As the most suitable sites to build are limited these new wind farms will be constructed near to each other in so called wind farm clusters. Behind the wind turbines in these farms there is a disrupted flow of air called a wake that is characterized by reduced wind speed and increased turbulence. LÄS MER