Sökning: "hydropower"

Visar resultat 21 - 25 av 178 avhandlingar innehållade ordet hydropower.

1. 21. Hydropower plants and power systems : Dynamic processes and control for stable and efficient operation

   Författare :Weijia Yang; Per Norrlund; Urban Lundin; Christophe Nicolet; Uppsala universitet; []
   Nyckelord :;

   Sammanfattning : As the largest global renewable source, hydropower shoulders a large portion of the regulation duty in many power systems. New challenges are emerging from variable renewable energy (VRE) sources, the increasing scale and complexity of hydropower plants (HPPs) and power grid. LÄS MER

3. 22. Internal Design of a Class of Self-Excited Synchronous Generators

   Författare :Mohamed Wadi; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Soft Magnetic Composites; Hydropower Plants; Brushless Excitation; Self-Excited Generators; Renewable Energy; Reluctance Generators; Synchronous Generators; Small Hydropower;

   Sammanfattning : INTERNAL DESIGN OF A CLASS OF SELF-EXCITEDABSTRACTWith the increasing trend of distributed generation and the need for alternative and renewable energy sources, self-excited induction and synchronous reluctance generators have attracted more attention for wind, tidal and hydropower applications. This thesis is concerned with the development of a class of self-excited synchronous reluctance generators (SRG). LÄS MER

4. 23. Conservation of landlocked Atlantic salmon in a regulated river : Behaviour of migratory spawners and juveniles

   Författare :Anna Hagelin; Eva Bergman; Fleming Ian; Karlstads universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Atlantic salmon; conservation; migration; spawning; hydropower; competition; juveniles; brown trout; hatchery reared; fallback; delay; Biology; Biologi;

   Sammanfattning : Hydropower dams represent one of the major threats to river ecosystems today. The dams block migratory routes in many rivers, which is problematic for migratory fish species. Trap-and-transport may be an alternative to fish passage solutions, as a strategy to compensate for lost river connectivity. LÄS MER

5. 24. Measurement and modelling of unbalanced magnetic pull in hydropower generators

   Författare :Mattias Wallin; Urban Lundin; Antero Arkkio; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Damper winding; eddy currents; field winding short circuit; finite element method; hydropower generator; parallel circuits; rotor eccentricity; salient poles; synchronous generators; synchronous machines; UMP; unbalanced magnetic pull.; Engineering Science with specialization in Science of Electricity; Teknisk fysik med inriktning mot elektricitetslära;

   Sammanfattning : Hydropower research is often perceived to be an old and exhausted field of study but with ageing equipment and the need for more intermittent operation caused by an increased share of other renewable energy sources new challenges lie ahead.The main focus of this dissertation are the electromagnetic forces resulting from nonuniform air gap flux, whether it be caused by rotor eccentricity or a faulty field winding. LÄS MER

7. 25. Civil Resistance in the Shadow of War : Explaining popular mobilization against dams in Myanmar

   Författare :Kyungmee Kim; Ashok Swain; Jonathan Hall; Dan Banik; Uppsala universitet; []
   Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Civil resistance; social movement; mobilization; armed conflict; hydropower; dam; identity; indigenous communities; Myanmar; Kachin; Karen; Ta’ang; Statskunskap; Political Science;

   Sammanfattning : Why do some conflict-affected communities collectively resist dam-building while others do not? State-backed development projects such as hydropower dams have been the subject of societal resistance in countries around the world. In armed conflict areas, local populations who organize nonviolent resistance through collective action against these high-impact projects face additional challenges, such as being targeted for violence and coercion by the authorities. LÄS MER