Sökning: "Capacitance"

Visar resultat 21 - 25 av 252 avhandlingar innehållade ordet Capacitance.

  1. 21. Modeling and characterization of novel MOS devices

    Författare :Stefan Persson; KTH; []
    Nyckelord :MOSFET; SiGe; high-k dielectric; metal gate; mobility; charge sheet model; retrograde channel structure; intrinsic charge; intrinsic capacitance; contact resistivity;

    Sammanfattning : Challenges with integrating high-κ gate dielectric,retrograde Si1-xGexchannel and silicided contacts in future CMOStechnologies are investigated experimentally and theoreticallyin this thesis. ρMOSFETs with either Si or strained Si1-xGex surface-channel and different high-κgate dielectric are examined. LÄS MER

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

    Författare :Roberto Felicetti; Urban Lundin; Andreas Binder; Uppsala universitet; []
    Nyckelord :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;

    Sammanfattning : 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. LÄS MER

  4. 23. 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. 24. Electrical Characterisations of Bearings

    Författare :Abhishek Joshi; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Ball bearing; Equivalent circuit model; Lubricants; Bearing Capacitance; Spherical bearing; Mechanical bearing; Bearing currents; Electrical conduction; Electrical characterisation;

    Sammanfattning : Mechanical bearings are an integral part of industry, and are used in various places in order to reduce friction between two interacting surfaces and are used to transmit power and loads. Mechanical bearings are one of the most extensively used components within the wind industry, but on the other hand they are also one of the most dominantly failing failed components. LÄS MER

  7. 25. High Voltage DC-biased Oil Type Medium Frequency Transformer; A Green Solution for Series DC Wind Park Concept

    Författare :Mohammad Kharezy; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; High voltage DC; Insulation design; Offshore wind farm; Leakage inductance; High power isolated DC DC converter; Dual active bridge; Medium-frequency power transformer; Parasitic capacitance; HVDC;

    Sammanfattning : The electric energy generated by remote offshore wind parks is transported to the consumers using high voltage submarine cables. On the generation site, such transmissions are realized today by collecting the energy produced by several wind turbines in a bulky and expensive transformer placed on a dedicated platform. LÄS MER