Search for dissertations about: "frequency stability"

Showing result 1 - 5 of 350 swedish dissertations containing the words frequency stability.

  2. 1. The Frequency of the Frequency : On Hydropower and Grid Frequency Control

    Author : Linn Saarinen; Urban Lundin; Per Norrlund; Bengt Carlsson; Kjetil Uhlen; Uppsala universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; hydropower; frequency control; governors; power system stability; inertia; primary control; Engineering Science with specialization in Science of Electricity; Teknisk fysik med inriktning mot elektricitetslära;

    Abstract : Variations in the electricity consumption and production connected to the power system have to be balanced by active control. Hydropower is the most important balancing resource in the Nordic system, and will become even more important as the share of variable renewable energy sources increases. READ MORE

  4. 2. Stability of Low-Frequency AC Railways : Models and Transient Stability

    Author : John Laury; Lars Abrahamsson; Math Bollen; Pablo Arboleya; Luleå tekniska universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electric Power Engineering; Elkraftteknik;

    Abstract : Low-frequency AC railway grids are unique in the sense that a only few countries around the world uses them, still however, they are an important parts of their countries infrastructures. Due to the usage of a dierent frequency than the public grid of the country, conversion of frequency is needed for the interconnection. READ MORE

  5. 3. Grid frequency stability from a hydropower perspective

    Author : Elin Dahlborg; Per Norrlund; Urban Lundin; Linn Saarinen; Katherine Elkington; Uppsala universitet; []
    Keywords : 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;

    Abstract : 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. READ MORE

  6. 4. Wind Turbine Models for Power System Stability Studies

    Author : Abram Perdana; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; fixed-speed; variable-speed; validation; modelling; power system stability; frequency stability; aggregated model; wind turbine; voltage stability;

    Abstract : The purpose of this thesis is to develop dynamic models of wind turbines for power system stability studies. More specifically, the wind turbine models are mainly intended for voltage and frequency stability studies. READ MORE

  7. 5. Fundamental Control Performance Limitations for Interarea Oscillation Damping and Frequency Stability

    Author : Joakim Björk; Karl H. Johansson; Lennart Harnefors; Joe H. Chow; KTH; []
    Keywords : 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;

    Abstract : 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). READ MORE