Sökning: "power curve"

Visar resultat 1 - 5 av 90 avhandlingar innehållade orden power curve.

1. 1. Power and Wake Dynamics of Hawkmoth Flight

   Författare :Kajsa Warfvinge; Evolutionär ekologi; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Insect flight; Aerodynamics; Wind tunnel; Particle Image Velocimetry PIV .; tomo-PIV; Power; Manduca sexta; Macroglossum stellatarum; Hawkmoth;

   Sammanfattning : Aerodynamic theory states that the power required to fly is related to flight speed with a ∪-shaped curve. This has been shown in vertebrates, but insects have been proposed to have a flat, or J-shaped power curve. LÄS MER

3. 2. Power Quality Disturbances and Protective Relays

   Författare :Fan Wang; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; overcurrent relays; component switching; frequency deviation; power system disturbance; protection algorithms; power quality; digital protective relays; impedance relays;

   Sammanfattning : This thesis combines knowledge from two areas: power quality and power system protection. Power quality concerns the effect of voltage disturbances on end-user equipment and of current disturbances on network components. Power system protection concerns the detection of faults in the system from measured voltages and currents. LÄS MER

4. 3. Modeling of Wind Turbines for Power System Studies

   Författare :Tomas Petru; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; flicker; fault response; power quality; wind turbine; power system stability; measurements; prediction; verification; grid simulation; modeling;

   Sammanfattning : The power quality impact of wind turbines on the electric grid and the response of the wind turbines to faults in the electric grid are investigated in this thesis. A detailed model of a stall-regulated, fixed-speed wind turbine system capable of predicting the flicker impact on the connected grid is presented and compared with field measurements. LÄS MER

5. 4. Noise, eigenfrequencies and turbulence behavior of a 200 kW H-rotor vertical axis wind turbine

   Författare :Erik Möllerström; Jonny Hylander; Fredric Ottermo; Hans Bernhoff; Göran Sidén; Mats Åbom; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; VAWT; H-rotor; eigenfrequency; semi-guy-wired tower; noise emission; sound power level; microphone array; turbulence intensity; power curve; Engineering Science with specialization in Science of Electricity; Teknisk fysik med inriktning mot elektricitetslära;

   Sammanfattning : Vertical-axis wind turbines (VAWTs) have with time been outrivaled by the today more common and economically feasible horizontal-axis wind turbines (HAWTs). However, VAWTs have several advantages which still make them interesting, for example, the VAWTs can have the drive train at ground level and it has been argued that they have lower noise emission. LÄS MER

7. 5. Power dissipation in car tyres

   Författare :Martin Fraggstedt; Svante Finnveden; Michael Brennan; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Acoustics; Akustik;

   Sammanfattning : Traffic is a major source of green house gases. The transport field stands for 32 % of the energy consumption and 28 % of the total CO2 emissions, where road transports alone causes 84 % of these figures. LÄS MER