Sökning: "Large-scale hydropower"

Visar resultat 1 - 5 av 21 avhandlingar innehållade orden Large-scale hydropower.

1. 1. Hydropower Area Equivalents : Reduced Models for Efficient Simulation of Large-Scale Hydropower Systems

   Författare :Evelin Blom; Lennart Söder; Arild Helseth; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Area Equivalent; Aggregation; Bilevel optimization; Large-scale hydropower; Power system simulation; Reduced model; Area-Ekvivalent; Aggregering; Två-nivå-optimering; Storskalig vattenkraft; Kraftsystemssimulering; Reducerad modell;

   Sammanfattning : With over 4000 TWh yearly electricity production worldwide, hydropower plays an important role in many power systems. Unlike many other renewable energy sources, hydropower has a certain degree of controllability and high levels of flexibility over several time scales. LÄS MER

3. 2. Distributed Stochastic Programming with Applications to Large-Scale Hydropower Operations

   Författare :Martin Biel; Mikael Johansson; Lennart Söder; David Woodruff; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; stochastic programming; distributed; algorithms; large-scale; optimization; hydropower; software; julia language; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : Stochastic programming is a subfield of mathematical programming concerned with optimization problems subjected to uncertainty. Many engineering problems with random elements can be accurately modeled as a stochastic program. In particular, decision problems associated with hydropower operations motivate the application of stochastic programming. LÄS MER

4. 3. 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

5. 4. Distributed Stochastic Programming with Applications to Large-Scale Hydropower Operations

   Författare :Martin Biel; Mikael Johansson; Stein W. Wallace; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : Stochastic programming is a subfield of mathematical programming concerned with optimization problems subjected to uncertainty. Many engineering problems with random elements can be accurately modeled as a stochastic program. In particular, decision problems associated with hydropower operations motivate the application of stochastic programming. LÄS MER

7. 5. Grid frequency stability from a hydropower perspective

   Författare :Elin Dahlborg; Per Norrlund; Urban Lundin; Linn Saarinen; Katherine Elkington; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Frequency control; frequency stability; grid codes; hydropower; inertia; Kaplan unit; model validation; Engineering Science with specialization in Science of Electricity; Teknisk fysik med inriktning mot elektricitetslära;

   Sammanfattning : Many AC grids suffer from decreased frequency stability due to less system inertia. This has increased the risk of large-scale blackouts. This thesis and its papers address the frequency stability problem from a hydropower perspective.Grid frequency stability assessments often require accurate system inertia estimates. LÄS MER