Sökning: "magnitude"

Visar resultat 21 - 25 av 1889 avhandlingar innehållade ordet magnitude.

  1. 21. Coriolis generated secondary currents and their effects on turbulent channel flow

    Författare :Rolf Larsson; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Vattenteknik; Water Resources Engineering;

    Sammanfattning : The influence of secondary currents on various hydrodynamic processes in channel flow is discussed. Different mechanisms that generate secondary currents are presented. LÄS MER

  3. 22. Mechanisms of Electrical Ageing of Oilimpregnated Paper due to Partial Discharges

    Författare :Mohamad Ghaffarian Niasar; Hans Edin; Ernst Gockenback; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; partial discharges; oil-impregnated paper; oil; transformer insulation; dielectric frequency response; breakdown strength; ion mobility; thermal ageing; electrical ageing; moisture in paper; life time; thermal breakdown.; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : In this thesis, partial discharge (PD) phenomenon in oil-impregnated paper (OIP) is investigated under accelerated electrical stress. The thesis is mainly focused on the characteristic of PD activity and the influence it has on the insulation properties of OIP. LÄS MER

  4. 23. Power quality analysis and techno-economic modeling for microgrids

    Författare :Jakob Nömm; Sarah Rönnberg; Math Bollen; Josep Guerrero; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Power Quality; Economy; Microgrids; Electric Power Engineering; Elkraftteknik;

    Sammanfattning : The work done in this thesis considers microgrids from two different aspects. Power quality and techno-economics of microgrids. Detailed power quality measurements have been made at a single house hydrogen-solar microgrid that consists of state-of-the-art energy efficiency technology, energy production and energy storage. LÄS MER

  5. 24. Analysis of High-Frequency Electrical Transients in Offshore Wind Parks

    Författare :Tarik Abdulahovic; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; very fast transient; surge protection; surge; transient overvoltage; restrikes; prestrikes; breaker; voltage escalation;

    Sammanfattning : In this thesis, a study of high frequency electromagnetic transient phenomena is performed. Models of various components needed for simulations of high frequency transients, such as for transformers, cables and breakers are developed. LÄS MER

  7. 25. Measurements and Modelling of Low-Frequency Disturbances in Induction Machines

    Författare :Torbjörn Thiringer; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : The thesis deals with the dynamic response of the induction machine to low-frequency perturbations in the shaft torque, supply voltage and supply frequency. Also the response of a two-machine group connected to a weak grid is investigated. LÄS MER