Search for dissertations about: "urban pull"

Showing result 1 - 5 of 12 swedish dissertations containing the words urban pull.

  2. 1. The Original Sin : On displacement through renoviction in Sweden

    Author : Emil Pull; Guy Baeten; Mustafa Dikec; Koefoed Lasse; Kirsten Simonsen; Domikina Polanska; Malmö universitet; []
    Keywords : SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Urbana studier; Urban studies;

    Abstract : .... READ MORE

  4. 2. Measurement and modelling of unbalanced magnetic pull in hydropower generators

    Author : Mattias Wallin; Urban Lundin; Antero Arkkio; Uppsala universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Damper winding; eddy currents; field winding short circuit; finite element method; hydropower generator; parallel circuits; rotor eccentricity; salient poles; synchronous generators; synchronous machines; UMP; unbalanced magnetic pull.; Engineering Science with specialization in Science of Electricity; Teknisk fysik med inriktning mot elektricitetslära;

    Abstract : Hydropower research is often perceived to be an old and exhausted field of study but with ageing equipment and the need for more intermittent operation caused by an increased share of other renewable energy sources new challenges lie ahead.The main focus of this dissertation are the electromagnetic forces resulting from nonuniform air gap flux, whether it be caused by rotor eccentricity or a faulty field winding. READ MORE

  5. 3. Improving the functionality of synchronous machines using power electronics

    Author : Fredrik Evestedt; Urban Lundin; C. Johan. D. Abrahamsson; Jon Kjellin; Uppsala universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Power electronics; Synchronous machines; Excitation systems; Magnetic thrust bearing; Starting synchronous machines; Split rotor; Rotating electronics; Magnetic fields; Measurement systems; Unbalanced magnetic pull; Harmonics; Engineering Science with specialization in Science of Electricity; Teknisk fysik med inriktning mot elektricitetslära;

    Abstract : With the advent of modern power electronics there is reason to explore what can be achieved when it is applied to a mature technology like synchronous machines. In this text several concepts will be presented on how it is possible to control forces and how to get better performance out of synchronous machines by using power electronics. READ MORE

  6. 4. Analysis and control of magnetic forces in synchronous machines

    Author : J. J. Pérez-Loya; Urban Lundin; Anouar Belahcen; Uppsala universitet; []
    Keywords : eccentricity; electromagnetics; electromagnetic forces; excitation; magnetic fields; magnetic forces; magnetic thrust bearing; rotor drive; split rotor; starting; synchronous generators; synchronous machines; synchronous motors; unbalanced magnetic pull; Engineering Science with specialization in Science of Electricity; Teknisk fysik med inriktning mot elektricitetslära;

    Abstract : In a synchronous machine, radial, tangential, and axial forces are generated. In this thesis, three different technologies to control them are proposed. The first one, involves the utilization of the radial forces that arise between the rotor and the stator. READ MORE

  7. 5. Run-Up Transient Analysis for Salient Pole Wound Field Synchronous Motors : Field winding and power electronics implications for a smoother and cooler asynchronous start

    Author : Roberto Felicetti; Urban Lundin; Andreas Binder; Uppsala universitet; []
    Keywords : apparent resistance; cable modeling; current control; transmission line model; eddy currents; field winding; frequency analysis response; Fourier Transform; impedance mismatch; main inductance; overvoltage; parasitic capacitance; partial discharge; quality factor; ringing; slew rate; stray inductance; voltage gradient; winding resonance frequency; asynchronous start; run-up; torque ripple; reluctance torque; Engineering Science with specialization in Science of Electricity; Teknisk fysik med inriktning mot elektricitetslära;

    Abstract : Salient Pole Wound Field Synchronous Machines have better efficiency at full load than asynchronous machines of the same capability. Moreover, where asynchronous machines need inherently to draw a magnetizing current from the grid, Salient Pole Wound Field Synchronous Machines can work efficiently at unity power factor. READ MORE