Sökning: "power density"

Visar resultat 6 - 10 av 636 avhandlingar innehållade orden power density.

  1. 6. Component and system design of a mild hybrid 48 V powertrain for a light vehicle

    Författare :Stefan Skoog; 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; Extra low voltage; Hybrid Electric Vehicle; 48 V; Li-ion battery; Calorimetric measurement; Oil cooling; Efficiency; Multi-phase; MOSFET; Power Electronics; Permanent Magnet Synchronous Machine; PWM; Inverter; Power density;

    Sammanfattning : This thesis presents contributions in three areas relevant for the development of 48 V mild hybrid electric powertrains for cars. The first part comprises methodologies and extensive testing of lithium-ion battery cells in order to establish the electric and thermal performance using equivalent circuit models. LÄS MER

  3. 7. Thermodynamic properties of humid air and their application in advanced power generation cycles

    Författare :Xiaoyan Ji; Jinyue Yan; Umberto Desideri; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; air-water mixture; humid air; properties; wet cycles; dry air; water; enthalpy; entropy; heat capacity; density; evaporative gas turbine; compressed air energy storage; Chemical engineering; Kemiteknik;

    Sammanfattning : Water or steam is added into the working fluid (often air) in gas turbines to improve the performance of gas turbine cycles. A typical application is the humidified gas turbine that has the potential to give high efficiencies, high specific power output, low emissions and low specific investment. LÄS MER

  4. 8. Power Control Systems in a Flywheel based All-Electric Driveline

    Författare :Janaína Gonçalves de Oliveira; Hans Bernhoff; Mats Leijon; Torbjörn Thiringer; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Flywheels; batteries; electric vehicles; control systems; power electronics; electric machines; efficiency.; Electric power engineering; Elkraftteknik; Electrical engineering; Elektroteknik; Electronics; Elektronik; Engineering Science with specialization in Science of Electricity; Teknisk fysik med inriktning mot elektricitetslära;

    Sammanfattning : Flywheel systems are attractive in hybrid and electric vehicles due to their ability to handle power during acceleration and braking. The combination of a flywheel device with a battery source has several advantages such as high peak power capacity, high energy density and reduction in the number of charge/discharge cycles of the battery. LÄS MER

  5. 9. There is power in a union : Trade union organization, union membership and union activity in Sweden

    Författare :Johanna Palm; Magnus Bygren; Tomas Berglund; Stockholms universitet; []
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; union organization; union density; union activity; social class; ideology; structural change; Sociology; sociologi;

    Sammanfattning : This thesis investigates what factors affect union organization and, to some degree, union activity in the face of declining union density in the majority of Western countries. Union structures have been changing in recent decades, not only in terms of declining membership but also because women and white-collar workers are becoming a more stable part of the membership base, whereas previously highly organized groups, such as blue-collar workers, are in decline. LÄS MER

  7. 10. Integrated In-Wheel Motors for Low Power Traction Application

    Författare :Prakashraj Kasinathan; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; electric golf cart; integral-slot; force density; flux-linkage; traction motors; forklift trucks; direct-drive; electric wheelchairs power wheelchairs; low speed machines; fractional-slot;

    Sammanfattning : This thesis is primarily concerned with the practical limits, imposed by magnetic saturation and thermal considerations, of the force density in low-speed permanent-magnet electric machines. The practical force density values obtainable in integral- and fractional-slot machines are determined. LÄS MER