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Visar resultat 6 - 10 av 666 avhandlingar som matchar ovanstående sökkriterier.

1. 6. Experimental studies of wind turbine wakes : power optimisation and meandering

   Författare :Davide Medici; Henrik Alfredsson; Martin O.L. Lansen; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; wind energy; power optimisation; active control; yaw; vortex shedding; wake meandering; Fluid mechanics; Strömningsmekanik;

   Sammanfattning : Wind tunnel studies of the wake behind model wind turbines with one, two and three blades have been made in order to get a better understanding of wake development as well as the possibility to predict the power output from downstream turbines working in the wake of an upstream one. Both two-component hot-wire anemometry and particle image velocimetry (PIV) have been used to map the flow field downstream as well as upstream the turbine. LÄS MER

3. 7. Artificial Intelligence-Based Characterization and Classification Methods for Power Quality Data Analytics

   Författare :Azam Bagheri; Math Bollen; Surya Santoso; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Power System; power Quality; Voltage Dip; Big Data; Deep Learning; Machine Learning; Active Learning; Consensus Contriol; Electric Power Engineering; Elkraftteknik;

   Sammanfattning : One of the important developments in the electric power system is the fast increasing amount of data. An example of such data is formed by the voltages and currents coming from power-quality measurements. LÄS MER

4. 8. On Efficient Transmission Balancing Operation : Capturing the Normal State Frequency and Active Power Dynamics

   Författare :Martin Nilsson; Lennart Söder; Julia Matevosyan; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Active Power Dynamics; Frequency Control; Normal State; Power System Balancing; Transmission System Operator; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : In an electric power system, there will always be an electric balance. Nevertheless, System Operators (SOs) often uses the term imbalance. Here, the term imbalance refers to the difference between trades and real-time measurements. LÄS MER

5. 9. High Efficiency Inductive Power Transfer Systems for Vehicle Charging

   Författare :Daniel Pehrman; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; dual-active bridge; power flow control; bi-directional; electric vehicles; electromagnetic fields; inductive power transfer; high efficiency; high power; three-phase;

   Sammanfattning : Awareness of climate change due to greenhouse gas emissions and air pollution has led to a transition from internal combustion engine vehicles to electric vehicles. Wireless charging by inductive power transfer is a promising solution for charging electric vehicles. LÄS MER

7. 10. Modeling Approaches for Active Antenna Transmitters

   Författare :Parastoo Taghikhani; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; thermal model.; MIMO; power amplifier; Active antenna transmitter; hybrid beamforming; electrothermal; active subarray antenna; nonlinear distortion;

   Sammanfattning : The rapid growth of data traffic in mobile communications has attracted interest to Multiple-Input-Multiple-Output (MIMO) communication systems at millimeter-wave (mmWave) frequencies. MIMO systems exploit active antenna arrays transmitter configurations to obtain higher energy efficiency and beamforming flexibility. LÄS MER