Sökning: "electrical properties"

Visar resultat 11 - 15 av 1669 avhandlingar innehållade orden electrical properties.

  1. 11. Characterization of electrical properties in 4H-SiC by imaging techniques

    Författare :John Österman; Anders Hallén; Vito Raineri; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electrical engineering; Elektroteknik; elektronik och fotonik; Electrical engineering; electronics and photonics; Elektroteknik; elektronik och fotonik;

    Sammanfattning : 4H-SiC has physical properties supremely suited for a variety of high power, high frequency and high temperature electronic device applications. To fully take advantage of the material's potential, several problems remain to be solved. LÄS MER

  3. 12. On methods of measuring magnetic properties of power transformers

    Författare :Claes Carrander; Göran Engdahl; Anders Bergqvist; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; No-load; magnetizing current; losses; diagnostics; delta; three-phase; power transformer; magnetic core; electrical steel; measurements; simulation; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : The core of a power transformer can weigh hundreds of tons, and represents a significant part of the total ownership cost of the transformer, in terms of both the construction cost and of the monetary cost of losses. It is therefore desirable to have a method of diagnosing the core to ensure optimal performance, and to enable the operator to plan repairs of damaged or defective cores. LÄS MER

  4. 13. Electrical Bioimpedance Cerebral Monitoring: Fundamental Steps towards Clinical Application

    Författare :Fernando Seoane Martinez; KTH; []
    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; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Biomedical Instrumentation; Ischemia; Hypoxia; Non-invasive Monitoring; Electrical Bioimpedance Spectroscopy; Stroke; Impedance Measurements; Brain Monitoring;

    Sammanfattning : Neurologically related injuries cause a similar number of deaths as cancer, and brain damage is the second commonest cause of death in the world and probably the leading cause of permanent disability. The devastating effects of most cases of brain damage could be avoided if it were detected and medical treatment initiated in time. LÄS MER

  5. 14. 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

  7. 15. Iron Losses in Electrical Machines - Influence of Material Properties, Manufacturing Processes, and Inverter Operation

    Författare :Andreas Krings; Juliette Soulard; Oskar Wallmark; Annette Mütze; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; AC machines; cobalt-iron; eddy current losses; electrical steel sheets; inverter-fed machines; iron alloys; iron loss measurements; machine design; magnetic hysteresis; magnetic losses; magnetic materials; nickel-iron; permanent magnet machines; silicon-iron; soft magnetic composites; slot-less machines; soft magnetic materials; thermal effects.; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : As the major electricity consumer, electrical machines play a key role for global energy savings. Machine manufacturers put considerable efforts into the development of more efficient electrical machines for loss reduction and higher power density achievements. LÄS MER