Sökning: "Electromechanical devices"

Visar resultat 11 - 15 av 34 avhandlingar innehållade orden Electromechanical devices.

  1. 11. Physical simulation, fabrication and characterization of Wide bandgap semiconductor devices

    Författare :Sadia Muniza Faraz; Qamar ul Wahab; Linköpings universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP;

    Sammanfattning : Wide band gap semiconductors, Zinc Oxide (ZnO), Gallium Nitride (GaN) and Silicon Carbide (SiC) have been emerged to be the most promising semiconductors for future applications in electronic, optoelectronic and power devices. They offer incredible advantages in terms of their optical properties, DC and microwave frequencies power handling capability, piezoelectric properties in building electromechanical coupled sensors and transducers, biosensors and bright light emission. LÄS MER

  3. 12. Non-intrusive Methods for Mode Estimation in Power Systems using Synchrophasors

    Författare :Vedran Peric; Luigi Vanfretti; Xavier Bombois; Cristian Rojas; Mani V. Venkatasubramanian; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Synchrophasors; Phasor measurement units; system identification; mode estimation; electromechanical oscillations; prediction error; signal selection; experiment design; probing; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : Real-time monitoring of electromechanical oscillations is of great significance for power system operators; to this aim, software solutions (algorithms) that use synchrophasor measurements have been developed for this purpose. This thesis investigates different approaches for improving mode estimation process by offering new methods and deepening the understanding of different stages in the mode estimation process. LÄS MER

  4. 13. Technology and properties of InP-based photonic crystal structures and devices

    Författare :Naeem Shahid; Srinivasan Anand; Rob W. vad der Heijden; KTH; []
    Nyckelord :Integrated optics materials; Photonic crystals; Planar waveguides; Dispersion; Band-gap; Mode-gap; mini-stopband; InP; Nanostructure fabrication; dry etching; mass transport; material reflow; reliability; SRA - ICT; SRA - Informations- och kommunikationsteknik;

    Sammanfattning : Photonic crystals (PhCs) are periodic dielectric structures that exhibit a photonic band gap; a range of wavelengths for which light propagation is forbidden. 2D PhCs exhibit most of the properties as their three dimension counterparts with a compatibility with standard semiconductor processing techniques such as epitaxial growth, electron beam lithography, Plasma deposition/etching and electromechanical lapping/polishing. LÄS MER

  5. 14. Power Electronics for Mitigation of Voltage Sags and Improved Control of AC Power Systems

    Författare :Marcio Magalhães de Oliveira; KTH; []
    Nyckelord :power electronics; power quality; voltage sags; voltage-source converters; Custom Power; FACTS; real-time simulations; solid-state devices;

    Sammanfattning : The thesis deals with the application of compensators andswitches based on power electronics in AC transmission anddistribution systems. The objective of the studieddevices/equipment is the power flow and voltage control intransmission systems and the mitigation of voltage sags andmomentary interruptions to critical loads in distributionsystems. LÄS MER

  7. 15. InP based Micromechanics for Vertical-Cavity Micro-Opto-Electro-Mechanical Systems

    Författare :Martin Strassner; KTH; []
    Nyckelord :MOEMS; vertical-cavity; InP; DBR; epitaxy; semiconductor processing; micromechanics; wavelength tunable devices; long-wavelength;

    Sammanfattning : During the past decade, the amount of transmitted data hasbeen boosted due to an increasing use of the World Wide Web(WWW), video and audio transmissions. In the late 90s, thetraditional technology using twisted copper cables was nolonger capable to provide enough transmission capacity for theconstantly increasing data traffic. LÄS MER