Sökning: "electrical insulation system"

Visar resultat 16 - 20 av 49 avhandlingar innehållade orden electrical insulation system.

  1. 16. Diagnostics of stator insulatin by dielectric response and variable frequency partial discharge measurements : a study of varied low frequencies in stator insulation, with particular attention to end-winding stress-grading

    Författare :Nathaniel Taylor; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electrical engineering; Elektroteknik;

    Sammanfattning : Stator insulation is a critical to the reliability of electrical generators and motors. It is common industrial practice to use electrical measurement of partial discharges (PD) and some form of current-voltage measurement as part of the condition assessment of stator insulation at maintenance times. LÄS MER

  3. 17. Ageing and characterisation of semiconducting glazes

    Författare :Heike Ullrich; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; outdoor insulation; HV-DC AC system; field monitoring; semiconducting surface insulator; ageing; laboratory testing;

    Sammanfattning : .... LÄS MER

  4. 18. On reliability modelling of ageing equipment in electric power systems with regard to the effect of maintenance

    Författare :Tommie Lindquist; Prof. Roland Eriksson; Dr. Lina Bertling; Docent Carl-Ejnar Sölver; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electrical power technology; Maintenance; reliability modelling; electrical power systems; ageing; failure mechanisms; Elkraftteknik; Electric power engineering; Elkraftteknik;

    Sammanfattning : Power system maintenance optimisation involves obtaining the minimum total costs, including preventive and corrective maintenance costs and the cost of failures for both supplier and customer. To calculate the cost of failure, information is needed about the equipment reliability characteristics. LÄS MER

  5. 19. Detection of Partial Discharges at Fast Rising Voltages

    Författare :Thomas Hammarström; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Partial discharges; cavities; repetitive voltages; high dV dt.; square like voltages; short rise time; measurements;

    Sammanfattning : The present demand for higher efficiency and flexibility in the energy sector has ledto an increased use of power electronic generated waveforms as these allow energyconversion between different frequencies including DC. The generated waveformsare usually synthesized by so called Pulse Width Modulation (PWM) techniques,where the desired waveform is approximated by a number of square shaped pulseswith a short rise time. LÄS MER

  7. 20. Effect of Dielectric and Magnetic Material Characteristics on Frequency Response of Power Transformers

    Författare :Nilanga Abeywickrama; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; frequency response analysis; dielectric insulation; Complex permeability; core magnetization; finite element method; transformer diagnosis.; high frequency modelling; magnetic viscosity; silicon steel;

    Sammanfattning : Frequency response analysis (FRA) technique has become increasingly popular for the assessment of mechanicalintegrity in power transformers. This method is based on the fact that the shape of the frequency response at higher frequencies is uniquely determined by the geometrical construction of the transformer. LÄS MER