Sökning: "Small Hydropower"

Visar resultat 11 - 15 av 33 avhandlingar innehållade orden Small Hydropower.

  1. 11. Fundamental Control Performance Limitations for Interarea Oscillation Damping and Frequency Stability

    Författare :Joakim Björk; Karl H. Johansson; Lennart Harnefors; Joe H. Chow; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Power system control; HVDC transmission control; interarea oscillations; power oscillation damping; small-signal stability; fundamental control limitations; frequency stability; hydro power; wind power; non-minimum phase; zero dynamics; eigenvalue analysis; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : With the transition towards renewable energy and the deregulation of the electricity markets, the power system is changing. Growing electricity demand and more intermittent power production increase the need for transfer capacity. Lower inertia levels due to a higher share of renewables increase the need for fast frequency reserves (FFR). LÄS MER

  3. 12. Rock mass behavior under hydropower embankment dams with focus on fracture erosion and rock mass stability

    Författare :Alexander Bondarchuk; Ignacio Escuder-Bueno; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Mining and Rock Engineering; Gruv- och Berganläggningsteknik;

    Sammanfattning : In Sweden there are about 190 large hydropower dams of varying age. According to the definition by the International Commission of Large Dams (ICOLD), if the height of the dam exceeds 15 m it is referred as large. Majority of these dams are of embankment type. LÄS MER

  4. 13. Dynamic modelling and analysis of vertical machines

    Författare :Erik Synnegård; Matti Rantatalo; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Datorstödd maskinkonstruktion; Computer Aided Design;

    Sammanfattning : Since Sweden’s hydropower plants are getting old and operating conditions have changed, there is a need for simulation tools to predict the functionality, durability and needs for maintenance. Also for breakdowns and major revisions, there is a benefit if dynamical problems could be predicted through simulations. LÄS MER

  5. 14. Polymeric Materials for Bearing Applications : Tribological Studies in Lubricated Conditions

    Författare :Arash Golchin; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Machine Elements; Maskinelement;

    Sammanfattning : One of the most important demands in hydropower and other industries today stems from the emphasis on preserving the environment. Usage of mineral and synthetic oils in sliding bearings of hydropower plants raises concerns about the environmental impact of these lubricants in case of spillage into downstream water. LÄS MER

  7. 15. Flow Over Large-Scale Naturally Rough Surfaces

    Författare :Robin Andersson; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Strömningslära; Fluid Mechanics;

    Sammanfattning : The fluid mechanical field of rough surface flows has been developed ever since the first experiments by Haagen (1854) and Darcy (1857). Although old, the area still holds merit and a surprising amount of information have to this day yet to be fully understood, which surely is a proof of its complexity. LÄS MER