Search for dissertations about: "Harmonic Analysis"

Showing result 31 - 35 of 153 swedish dissertations containing the words Harmonic Analysis.

  2. 31. Design and characterisation of terahertz Schottky diode harmonic mixers

    Author : Divya Jayasankar; RISE Research Institutes of Sweden; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Schottky diodes; Phase locking; Harmonic mixers; Heterodyne receivers; Terahertz electronics; Frequency stabilisation; Frequency converters;

    Abstract : Efficient, compact, and reliable terahertz frequency converters preferably operating at ambient temperature are crucial for stabilising far-infrared optical sources. This thesis focuses on the design and characterisation of terahertz Schottky diode harmonic mixers for frequency stabilisation of quantum-cascade lasers. READ MORE

  4. 32. Dynamic Analysis of Harmonics in Electrical Systems

    Author : Erik Möllerstedt; Institutionen för reglerteknik; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Automation; converter control; modeling; linear time periodic systems; frequency domain analysis; harmonics; power systems; small signal stability; robotics; control engineering; Automatiska system; robotteknik; reglerteknik;

    Abstract : Frequency domain analysis and design of power systems is complicated in the presence of harmonics, switching dynamics, nonlinearities, unbalances, and for systems with mixed ac/dc dynamics. The reason is that linearization of the system does not lead to a time invariant system, but a system with periodically time varying dynamics, which implies that there is coupling between different frequencies. READ MORE

  5. 33. Topics in Analysis and Computation of Linear Wave Propagation

    Author : Mohammad Motamed; Olof Runborg; Shi Jin; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Numerical analysis; Numerisk analys;

    Abstract : This thesis concerns the analysis and numerical simulation of wave propagation problems described by systems of linear hyperbolic partial differential equations. A major challenge in wave propagation problems is numerical simulation of high frequency waves. READ MORE

  6. 34. Calculated Potential Energy Surfaces and Vibrational Analysis

    Author : Niclas Forsberg; Beräkningskemi; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Benzene; HCO; NEMO; Imaginary Level Shift; Double Harmonic Approximation; Potential Energy Surface; CASPT2; Franck-Condon Factors; CASSCF; p-Benzosemiquinone; Theoretical chemistry; quantum chemistry; Teoretisk kemi; kvantkemi;

    Abstract : The focus of this thesis is on the calculation of potential energy surfaces and on the study of vibrational properties. For example: - We have developed a new method for calculation of Franck-Condon factors. - We have calculated full energy surfaces of the ground (X2A’) the excited (B2A’) states of the formyl radical. READ MORE

  7. 35. Multilevel three-phase dual active bridge dc-dc converters - A study on converter modulation, capacitive energy requirement, ZVS boundaries, MFT's winding connections, and core losses

    Author : Babak Alikhanzadehalamdari; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; high-voltage power converters; dual active bridge; harmonic analysis; three-phase system; medium-frequency transformer; capacitor sizing; multilevel converters; high power-density systems; transformer winding connection; core loss modeling; dc collector network; soft-switching converters;

    Abstract : The collection and transmission of power from offshore wind turbines using dc have advantages over the ac system. One of the enabling technologies for deploying dc collection is the dc-dc converter that boosts the dc output from the turbine to the medium-voltage dc level of the collection grid. READ MORE