Sökning: "Eddy currents"

Visar resultat 11 - 15 av 37 avhandlingar innehållade orden Eddy currents.

  1. 11. 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

  3. 12. On the Design of Ultra-fast Electro-Mechanical Actuators

    Författare :Ara Bissal; Göran Engdahl; Torbjörn Lembke; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electro-mechanical drive; Circuit breakers; HVDC transmission; Eddy currents; Finite element; Electromagnetic; Thermal; Mechanical; Coils; Armature; Image motion analysis.;

    Sammanfattning : The continuously increasing demand for connecting electric grids with remote renewable energy sources such as wind power and photovoltaic cells has rekindled interest in high voltage direct current (HVDC) multi-terminal networks. Although HVDC networks have numerous benefits, their adoption relies entirely on the availability of HVDC circuit breakers which, compared to traditional alternating current circuit breakers, have to operate in a time frame of milliseconds. LÄS MER

  4. 13. Voltage Transients in the Field Winding of Salient Pole Wound Synchronous Machines : Implications from fast switching power electronics

    Författare :Roberto Felicetti; Urban Lundin; Jon Kjellin; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; 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;

    Sammanfattning : Wound Field Synchronous Generators provide more than 95% of the electricity need worldwide. Their primacy in electricity production is due to ease of voltage regulation, performed by simply adjusting the direct current intensity in their rotor winding. LÄS MER

  5. 14. Modelling and design approaches of magnetostrictive actuators

    Författare :Mattias Oscarsson; Göran Engdahl; Tord Cedell; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Magnetostriction; Terfenol; Coil optimisation; Leakage flux; Modelling tools; Eddy currents; Magnetostriktion; Electrical engineering; Elektroteknik;

    Sammanfattning : A magnetostrictive material elongates when it is subjected to a magnetic field. This effect can then be used to design powerful actuators. LÄS MER

  7. 15. Mitigation of Power-Frequency Magnetic Fields With Applications to Substations and Other Parts of the Electric Network

    Författare :Ener Salinas; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; substation; power-frequency magnetic fields; EMC; FEM; busbars; transformers; field mitigation; eddy currents;

    Sammanfattning : In recent times, electromagnetic emissions from various electrical components have induced more than one debate whether they represent a harmful influence to our health. In addition, interferences caused by power frequency magnetic fields (PFMFs) on electron beam based electronic equipment (e.g. LÄS MER