Search for dissertations about: "unbalance"

Showing result 6 - 10 of 24 swedish dissertations containing the word unbalance.

  2. 6. Operation and control of cascaded H-bridge converter for STATCOM application

    Author : Ehsan Behrouzian; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Modular Multilevel Converters MMC ; STATCOM; FACTS.; cascaded H-bridge converters;

    Abstract : In the last decade, particular attention has been paid to the use of Modular Multilevel Converters(MMC) for grid applications. In particular, for STATCOM applications the phase leg ofthe converter is constituted by a number of single-phase full-bridge converters connected incascade (here named Cascaded H-Bridge, CHB, converter). READ MORE

  4. 7. Condition monitoring of machine tools and machining processes using internal sensor signals

    Author : Jari Repo; Mihai Nicolescu; Dragos Axiente; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; condition monitoring; machine tool; machining process; milling; position encoders; signal analysis; Mechanical engineering; Maskinteknik; Materials science; Manufacturing and materials engineering;

    Abstract : Condition monitoring of critical machine tool components and machining processes is a key factor to increase the availability of the machine tool and achieving a more robust machining process. Failures in the machining process and machine tool components may also have negative effects on the final produced part. READ MORE

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

    Author : Roberto Felicetti; Urban Lundin; Jon Kjellin; Uppsala universitet; []
    Keywords : 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;

    Abstract : 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. READ MORE

  6. 9. Characterization of fibroblast phenotypes in human airway remodeling

    Author : Kristoffer Larsen; Lungbiologi; []
    Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Medicine human and vertebrates ; Medicin människa och djur ; remodeling; General biomedical sciences; Biomedicinska vetenskaper allmänt ; fibrocytes; proteoglycans; Asthma; fibroblasts;

    Abstract : Wound healing that precedes scar formation may be unbalanced under pathological conditions leading to structural changes of the tissue. At the moment, the mechanisms behind this unbalance are unclear. When these changes occur in internal organs such as the lung, they may result in organ dysfunction with fatal consequences for the patient. READ MORE

  7. 10. Evaluation of strong nonlinearities in hydropower systems

    Author : Florian Thiery; Ilmar Santos; Luleå tekniska universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Hållfasthetslära; Solid Mechanics;

    Abstract : In hydropower systems, it is essential to avoid catastrophic failures that leads to human and economic losses. Unfortunately, the rotor can behave abnormally since several nonlinear effects occur during start-up, shut downs or when running at nominal speed. READ MORE