Sökning: "high-frequency measurements"

Visar resultat 16 - 20 av 169 avhandlingar innehållade orden high-frequency measurements.

  1. 16. On high-frequency distortion in low-voltage power systems

    Författare :Anders Larsson; Lars Gertmar; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electric Power Engineering; Elkraftteknik; Energy Engineering; Energiteknik;

    Sammanfattning : Power quality is a subject that has received a lot of attention during the last 10 to 20 years, both in industry and in academia. Power quality concerns interaction between the power grid and its customers and between the power grid and equipment connected to it, reflected in voltages and currents. LÄS MER

  3. 17. Time-domain modelling of high-frequency wheel/rail interaction

    Författare :Astrid Pieringer; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; wheel rail interaction; railway noise; roughness; time domain; frictional instability; discrete irregularities; transient contact; non-Hertzian contact;

    Sammanfattning : The interaction between wheel and rail is the predominant source of noise emission from railway operations in a wide range of conventional speeds. On the one hand, this wheel/rail noise concerns rolling noise and impact noise caused by the vertical interaction excited by roughness and discrete irregularities of the wheel/rail running surfaces, respectively. LÄS MER

  4. 18. High-frequency noise in power grids, neutral and protective earth

    Författare :Martin Lundmark; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Energy Engineering; Energiteknik;

    Sammanfattning : This licentiate thesis deals with the high-frequency distortion, 1 kHz and higher, introduced into the power grid by the numbers of power converters in use today. These devices can be a source of electromagnetic interference and equipment damage despite the fact that the equipment complies product-standards testing. LÄS MER

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

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

    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 transformers, cables and breakers are developed. LÄS MER

  7. 20. 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