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Visar resultat 1 - 5 av 20 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Pulse-Width Modulated RF Transmitters

    Författare :Muhammad Fahim Ul Haque; Ted Johansson; Dake Liu; Qamar Ul Wahab; Franz Dielacher; Linköpings universitet; []
    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; NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : The market for wireless portable devices has grown signicantly over the recent years.Wireless devices with ever-increased functionality require high rate data transmissionand reduced costs. LÄS MER

  3. 2. Reduction of Audible Noise of a Traction Motor at PWM Operation

    Författare :Hanna Amlinger; Ines Lopez Arteaga; Siv Leth; Wolfgang Kropp; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; electromagnetic noise; pulse width modulation PWM ; switching frequency; traction motor; Vehicle and Maritime Engineering; Farkostteknik;

    Sammanfattning : A dominating source for the radiated acoustic noise from a train at low speeds is the traction motor. This noise originates from electromagnetic forces acting on the structure resulting in vibrations on the surface and thus radiated noise. It is often perceived as annoying due to its tonal nature. LÄS MER

  4. 3. All-Digital PWM Transmitters

    Författare :Muhammad Touqir Pasha; Ted Johansson; Mark Vesterbacka; Henrik Sjöland; Linköpings universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : Electronic devices with wireless connectivity are fast becoming a part of daily life. According to some estimates, in the next five years, 10 billion new devices with internet connectivity would be produced. LÄS MER

  5. 4. The control of VSC-HVDC and its use for large industrial power systems

    Författare :Cuiqing Du; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; VSC-HVDC; inner current controller; outer controller; PWM; dc dc converter; voltage dips; dc networks;

    Sammanfattning : With the recent developments in semiconductors and control equipment, Voltage Source Converter based High Voltage direct Current (VSC-HVDC) has become feasible. Due to the use of VSC technology and Pulse Width Modulation (PWM), it has a number of potential advantages: short circuit current reduction; rapid, independent control of the active and reactive power, etc. LÄS MER

  7. 5. Modeling and Control of Voltage Source Converters Connected to the Grid

    Författare :Michael Lindgren; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; voltage source converter; switching frequency; pulse width modulation; IGBT valve; power electronics; small-signal; L-filter; LCL-filter; transfer function; line filter; active filtering; frequency response; sampling frequency;

    Sammanfattning : This thesis deals with the modeling and control of pulse width modulated (PWM) voltage source converters connected to the grid. When voltage source converters are connected to the grid, the power quality and the dynamic performance are affected by the line filter connected between the converter and the grid, and by nonlinearities caused by the switching converter. LÄS MER