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Visar resultat 11 - 15 av 33 uppsatser som matchar ovanstående sökkriterier.

1. 11. Analysis of uncertainties in fatigue load assessment : a study on one Kaplan hydro turbine during start operation

   Master-uppsats, KTH/Skolan för industriell teknik och management (ITM)

   Författare :Annica Gustafsson; [2019]
   Nyckelord :Hydropower; Hydro turbine runner; Uncertainty analysis; Fatigue load; Fatigue damage; Propagation of uncertainty.; Vattenkraft; Löphjul; Osäkerhetsanalys; Utmattning; Delskada; Fortplantning av osäkeheter.;

   Sammanfattning : In the future, hydropower plants are expected to operate more flexibly. This will lead to a more varied operation of the turbine and the generator, such as more start and stop in order to stabilise the frequency in the grid. Studies show that these transient operations are more costly in terms of fatigue degradation, i.e. LÄS MER

3. 12. Anpassning av småskaliga vattenkraftverk för ö-drift av lokalt elnät

   Uppsats för yrkesexamina på avancerad nivå, Uppsala universitet/Elektricitetslära

   Författare :Jonatan Fredriksson; [2019]
   Nyckelord :small hydropower; hydropower; Kaplan; turbine; transient; disturbance; resilliance; power grid; island; islanding; adapting; island mode; frequency control; dummy load; Kaplan; Kaplanturbin; elnät; ö-nät; ö-drift; vattenkraft; småskaliga vattenkraftverk; transient störningstålighet; indexprov; kombineringsprov; lokalt elnät;

   Sammanfattning : This master thesis examines technical requirements for small hydro power plants (HPP) to operate proximate parts of the power grid in island mode. The work examines how small hydropower can be modified and complemented with additional technologies to achieve sufficient frequency control capabilities. LÄS MER

4. 13. Machine learning for condition monitoring in hydropower plants using a neural network

   Uppsats för yrkesexamina på avancerad nivå, Luleå tekniska universitet/Institutionen för teknikvetenskap och matematik

   Författare :Tina Stark; [2019]
   Nyckelord :Machine learning; hydropower; condition monitoring; neural network; Kaplan; turbine; feedforwardnet;

   Sammanfattning : The hydro power industry stands for new challenges due to a more fluctuating production fromwind and solar power. This requires more regulation of the production in the hydro powerstations, which increases maintenance demands. An oil leakage has not only consequencessuch as downtimes and maintenance costs, but also an environmental impact. LÄS MER

5. 14. Analys av tryckmätningar i Kaplanturbiner

   Uppsats för yrkesexamina på avancerad nivå, Uppsala universitet/Institutionen för fysik och astronomi

   Författare :Andreas Särnblad; [2019]
   Nyckelord :Hydropower; pressure transients; Vattenkraft; trycktransienter;

   Sammanfattning : In a risk situation the flow through a hydropower turbine must be reduced under a short amount of time. The reduction in flow causes low pressures in the region called draft tube under the runner in the turbine. If the pressure drops below vapor pressure the water in the turbine may evaporate and form large cavities. LÄS MER

7. 15. Preliminary simulation of Porjus U9 turbine at speed no load

   Uppsats för yrkesexamina på avancerad nivå, Luleå tekniska universitet/Institutionen för teknikvetenskap och matematik

   Författare :Henrik Holmström; [2019]
   Nyckelord :Kaplan; Speed no-load; SNL;

   Sammanfattning : Hydropower plants are shifting towards operating at off-designed conditions, meaning that the number of start-stop cycles and maintenance time due to cavitation increases. The speed no-load condition is the moment before magnetization of the generator, i.e., no load, low flow, constant runner rotational speed, guide vane and runner blade angle. LÄS MER