Sökning: "Frequency converter"

Visar resultat 6 - 10 av 145 uppsatser innehållade orden Frequency converter.

  1. 6. Comparison between active and passive rectification for different types of permanent magnet synchronous machines

    Uppsats för yrkesexamina på avancerad nivå, Uppsala universitet/Elektricitetslära

    Författare :Johannes Örnkloo; [2018]
    Nyckelord :PMSG; PMSM; rectification; saliency; converter; wind power;

    Sammanfattning : When using an intermittent source of energy such as wind power together with a synchronous machine a frequency converter system is needed to decouple the generator from the grid, due to the fluctuations in wind speed resulting in fluctuating electrical frequency. The aim of this master's thesis is to investigate how different types of rectification methods affect permanent magnet synchronous machines of different saliency ratios. LÄS MER

  2. 7. Analysis of harmonic cross-modulation in HVDC line-commutated converters for practical design purposes

    Uppsats för yrkesexamina på grundnivå, Högskolan Väst/Avdelningen för Industriell ekonomi, Elektro- och Maskinteknik

    Författare :Casper Karlsson; [2018]
    Nyckelord :Power transmission; design; filters;

    Sammanfattning : The use of HVDC has many benefits over HVAC for some specific power transmission purposes. However, two major problems with HVDC links are that the converters produce harmonics and consume reactive power. Electrical filters are used to compensate for this and are a major cost driver of HVDC links. LÄS MER

  3. 8. Design of Resonant Filters for AC Current Magnification : Heating of Li-ion Batteries by Using AC Currents

    Master-uppsats, KTH/Skolan för elektroteknik och datavetenskap (EECS)

    Författare :Nikolina Djekanovic; [2018]
    Nyckelord :Current control; injection of alternating current; internal heat dissipation; LCL filter; Lithium-ion batteries; power efficiency; resonance phenomenon;

    Sammanfattning : Using alternating current in order to heat batteries at sub-zero temperatures is a method,which is investigated in-depth by an increasing number of study groups. The thesis considersthe resonance phenomenon with the intention to use alternating current amplificationand battery’s impedance in order to induce power dissipation inside the battery, and in thisway increase its temperature. LÄS MER

  4. 9. Digitally Controlled Oscillator for mm-Wave Frequencies

    Master-uppsats, Lunds universitet/Institutionen för elektro- och informationsteknik

    Författare :Rikard Gannedahl; Johan Holmstedt; [2018]
    Nyckelord :RF; RFIC; oscillator; DCO; mm-wave; Technology and Engineering;

    Sammanfattning : In the fifth generation of mobile communication, 5G, frequencies above 30 GHz, so-called millimeter-wave (mm-wave) frequencies are expected to play a prominent role. For the synthesis of these frequencies, the all-digital phase locked loop (ADPLL) has recently gained much attention. LÄS MER

  5. 10. Comparison of High-Power DC-DC Converters for Solar Applications with Respect to Efficiency and Chip-area

    H-uppsats, Chalmers tekniska högskola/Institutionen för elektroteknik

    Författare :Babak Alikhanzadehalamdari; [2018]
    Nyckelord :SST; DC-DC converter; DAB; NPC; Efficiency; Chip area; PV;

    Sammanfattning : This thesis is intended to analyze and compare the efficiency of the conventional2L-DAB with the so-called Multi-Level DAB (ML-DAB) and three-Level DAB (3LDAB)for the solar applications. The latter features from the three-level legs bothon the LV and the MV sides; while, the former is a combination of the 2L-legs onthe LV side bridge and the NPC legs on the MV side bridge. LÄS MER