Search for dissertations about: "Electrical Discharges"

Showing result 1 - 5 of 60 swedish dissertations containing the words Electrical Discharges.

  1. 1. Mechanisms of Electrical Ageing of Oilimpregnated Paper due to Partial Discharges

    Author : Mohamad Ghaffarian Niasar; Hans Edin; Ernst Gockenback; KTH; []
    Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; 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;

    Abstract : 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. READ MORE

  2. 2. Physics of Electrical Discharge Transitions in Air

    Author : Lipeng Liu; Marley Becerra; Ute Ebert; KTH; []
    Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; electrical discharges; transition; streamers; glow corona; leader discharges; elektriska urladdningar; övergång; streamers; glöd-korona; ledarurladdningar; Electrical Engineering; Elektro- och systemteknik;

    Abstract : Electrical discharges with a variety of different forms (streamers, glow corona, leaders, etc.) broadly exist in nature and in industrial applications. Under certain conditions, one electrical discharge can be transformed into another form. READ MORE

  3. 3. Numerical modelling of positive electrical discharges in long air gaps

    Author : Oscar Diaz; Vernon Cooray; Raul Montano; Uppsala universitet; []
    Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; high voltage techniques; numerical modeling; electrical discharge in gases; streamer mechanism; leader channel; Engineering Science with specialization in Atmospheric Discharges; Teknisk fysik med inriktning mot atmosfäriska urladdningar;

    Abstract : This dissertation deals with research on the numerical modelling of electrical discharges in laboratory long air gaps excited with positive switching impulses. It begins with the preliminary work of several scientists during the last decades, making a detailed analysis of different approaches for modelling all the stages in a full discharge. READ MORE

  4. 4. Modelling of cavity partial discharges at variable applied frequency

    Author : Cecilia Forssén; Roland Eriksson; Hans Edin; Peter H.F. Morshuis; KTH; []
    Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; partial discharges; measurements; modelling; variable frequency; cavities; disc-shaped; polycarbonate; Electric power engineering; Elkraftteknik;

    Abstract : The presence of partial discharges (PD) in high voltage components is generally a sign of defects and degradation in the electrical insulation. To diagnose the condition of high voltage insulation, PD measurements is commonly used. READ MORE

  5. 5. Dielectric properties of poly(ethyelene-co-butyl acrylate) filled with Alumina nanoparticles

    Author : Nadejda Jäverberg; Hans Edin; Eva Mårtensson; KTH; []
    Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; nanocomposites; poly ethylene-co-butyl acrylate ; EBA; alumina; dielectric permittivity; absorbed water; humidity; temperature; dielectric spectroscopy; partial discharge; electrical treeing; Electrical engineering; Elektroteknik;

    Abstract : In this work dielectric properties of the poly(ethylene-co-butyl acrylate)filled with alumina nanoparticles are evaluated. These nanocomposite materialswere manufactured at the department of Fibre and Polymer Technology,KTH.This study is limited to the properties of general importance for the AC applications. READ MORE