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Visar resultat 1 - 5 av 88 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Analysis and control of magnetic forces in synchronous machines

    Författare :J. J. Pérez-Loya; Urban Lundin; Anouar Belahcen; Uppsala universitet; []
    Nyckelord :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;

    Sammanfattning : 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. LÄS MER

  3. 2. Modeling and Verification of Ultra-Fast Electro-Mechanical Actuators for HVDC Breakers

    Författare :Ara Bissal; Göran Engdahl; Elena Lomonova; KTH; []
    Nyckelord :Actuators; Armature; Capacitors; Circuit breakers; Coils; Damping; Eddy currents; Elasticity; Electro-mechanical devices; Electromagnetic forces; Finite element methods; HVDC transmission; Image motion analysis; Magnetic domains; Magnetic flux; Magnetic forces; Magnetic materials; Magnets; Thermal analysis; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : The continuously increasing demand for clean renewable energy has rekindled interest in multi-terminal high voltage direct current (HVDC) grids. Although such grids have several advantages and a great potential, their materialization has been thwarted due to the absence of HVDC breakers. LÄS MER

  4. 3. Controlled manipulation of microparticles utilizing magnetic and dielectrophoretic forces

    Författare :LarsErik Johansson; Sven Oscarsson; Leif Nyholm; Mälardalens högskola; []
    Nyckelord :Dielectrophoresis; Magnetic beads; MEMS; Micro-particles; Micro-scale manipulation; Micro-system; Biotechnology Chemical Engineering; bioteknik kemiteknik;

    Sammanfattning : This thesis presents some experimental work in the area of manipulation of microparticles. Manipulation of both magnetic and non magnetic beads as well as microorganisms are addressed. The work on magnetic bead manipulation is focused on controlled transport and release, on a micrometer level, of proteins bound to the bead surface. LÄS MER

  5. 4. Modeling of induction stirred ladles

    Författare :Mayur Pal; Pär Jönsson; Pavel Ramirez Lopez; KTH; []
    Nyckelord :induction ladle; electromagnetic; Lorentz forces; magnetic stirrer; magnetic diffusion; Navier-Stokes; FEM;

    Sammanfattning : Over the years numerous computational fluid dynamics models have been developed in order to study the fluid flow in gas and induction stirred ladles. These models are used to gain insight in the industrial processes used in ladle treatment of steel. A unified model of an induction stirred Ladle in two and three dimensions is presented. LÄS MER

  7. 5. Improved performance characteristics of induction machines with non-skewed symmetrical rotor slots

    Författare :Rathna Chitroju; Chandur Sadarangani; Kelvin C Maliti; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; skewing; cross current losses; radial magnetic forces; magnetic noise; asymmetrical rotor slots; eccentricity; stator vibration; two-dimensional fast fourier transform; finite element method; Electrical engineering; electronics and photonics; Elektroteknik; elektronik och fotonik;

    Sammanfattning : Induction machines convert more than 55% of electrical energy into various other forms in industrial and domestic environments. Improved performance, especially by reduction of losses in induction machines hence can significantly reduce consumption of electricity. LÄS MER