Sökning: "Power converter"

Visar resultat 6 - 10 av 295 avhandlingar innehållade orden Power converter.

1. 6. Study of Induction Machines with Rotating Power Electronic Converter

   Författare :Yanmei Yao; Chandur Sadarangani; Zi-Qiang Zhu; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Brushless induction machine; efficiency improvement; optimum efficiency; rotating power electronic converter; unity power factor; variable power factor; wound rotor induction machine; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : This thesis investigates a novel induction machine topology that uses a rotating power electronic converter. Steady-state and dynamic performance of the topology is studied to understand its operational principle. Furthermore the potential of improving its efficiency and power factor is investigated. LÄS MER

3. 7. Wave Power for Desalination

   Författare :Jennifer Leijon; Cecilia Boström; Irina Temiz; Jens Engström; Deborah Greaves; Uppsala universitet; []
   Nyckelord :Wave power; desalination; freshwater; engineering education; linear generator; wave energy converter; Engineering Science with specialization in Science of Electricity; Teknisk fysik med inriktning mot elektricitetslära;

   Sammanfattning : This doctoral thesis presents work related to wave powered desalination. Wave power for desalination could be an interesting alternative for islands or coastal regions facing freshwater shortage, and several systems have been proposed in literature. However, desalination is a process which demands a lot of energy. LÄS MER

4. 8. On soft-switching isolated AC/DC converters without auxiliary circuit

   Författare :Staffan Norrga; Stefan Östlund; Rik De Doncker; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electrical power technology; voltage source converter; cycloconverter; isolated converter; medium frequency transformer; soft switching; modulation; commutation; wind power; electric traction; Elkraftteknik; Electric power engineering; Elkraftteknik;

   Sammanfattning : The thesis is concerned with a class of power electronic converter systems that permit bidirectional AC/DC conversion with galvanic separation of the AC and DC sides by a transformer operating at elevated frequency. The systems consist of a capacitively snubbered voltage source converter and a cycloconverter, separated by the mentioned transformer. LÄS MER

5. 9. Wind-turbine harmonic emissions and propagation through a wind farm

   Författare :Kai Yang; Åke Larsson; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Renewable energy; Electric power system; Wind power; Power quality; Power system harmonics; Electric Power Engineering; Elkraftteknik; Energy Engineering; Energiteknik;

   Sammanfattning : The increasing demand for sustainable energy is one of the driving forces behind the increasing use of wind power by means of wind-turbines in electric power systems. Modern wind turbines commonly employ variable-speed-generator technology associated with a power-electronic converter as part of the grid connection. LÄS MER

7. 10. Frequency response by wind farms in power systems with high wind power penetration

   Författare :Mattias Persson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; inertia estimation; frequency control; power system stability; wind power integration; Power system; synthetic inertia;

   Sammanfattning : The integration of variable speed wind turbines (VSWT) in power systems is increasing in order to reduce the emission of green house gases. This increase of power electronic converter interfaced generation causes a decrease of power system inertia, increasing the risk of load shedding and system frequency instability. LÄS MER