Sökning: "power losses"

Visar resultat 21 - 25 av 400 avhandlingar innehållade orden power losses.

  1. 21. Electromagnetic transformer modelling including the ferromagnetic core

    Författare :David Ribbenfjärd; Göran Engdahl; David Jiles; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Power transformer; hysteresis; dynamic hysteresis; dynamic magnetization; eddy currents; excess losses; leakage flux; winding model; core model; magnetic measurements; magnetic materials; Electric power engineering; Elkraftteknik;

    Sammanfattning : In order to design a power transformer it is important to understand its internal electromagnetic behaviour. That can be obtained by measurements on physical transformers, analytical expressions and computer simulations. LÄS MER

  3. 22. Modular Battery Systems for Electric Vehicles based on Multilevel Inverter Topologies - Opportunities and Challenges

    Författare :Anton Kersten; 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; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Dynamic reconfiguration; Energy storage; Energy efficiency; Drive cycle efficiency; Power MOSFET; vehicles; H-bridge; Multilevel systems; Electromagnetic compatibility; Modular battery systems; Battery system performance; Modular multilevel converters; Conduction losses; Electric vehicles; Batteries; Dual battery pack; Cascaded converters; DC-AC power converters; BMS; Common mode noise; Battery modeling; vehicle electrification;

    Sammanfattning : Modular battery systems based on multilevel inverter (MLI) topologies can possibly overcome some shortcomings of two-level inverters when used for vehicle propulsion. The results presented in this thesis aim to point out the advantages and disadvantages, as well as the technical challenges, of modular vehicle battery systems based on MLIs in comparison to a conventional, two-level IGBT inverter drivetrain. LÄS MER

  4. 23. Fossil Capital : The Rise of Steam-Power in the British Cotton Industry, c. 1825-1848, and the Roots of Global Warming

    Författare :Andreas Malm; Humanekologi; []
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Fossil economy; steam-power; water-power; cotton industry; Britain; capital accumulation; global warming;

    Sammanfattning : The more we know about the catastrophic implications of climate change, the more fossil fuels are burnt in the world. How did we get caught up in this mess? This thesis returns to a crucial moment in the emergence of the fossil economy: the rise of steam-power. LÄS MER

  5. 24. Modelling approaches for audio frequency power transformers

    Författare :Julius Krah; KTH; []
    Nyckelord :power transformer; audio frequency; loss; hysteresis; eddy currents; skin effect. Leakage inductance;

    Sammanfattning : The development of HVDC converters, local generation andtractions systems increases the demand for power converters.While a lot of studies have been conducted on the powerelectronics, there are still open questions concerning thecontained power transformer that operates at a few kilohertz. LÄS MER

  7. 25. 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