Search for dissertations about: "variable frequency"

Showing result 1 - 5 of 181 swedish dissertations containing the words variable frequency.

  1. 1. The Frequency of the Frequency On Hydropower and Grid Frequency Control

    University dissertation from Uppsala : Acta Universitatis Upsaliensis

    Author : Linn Saarinen; Uppsala universitet.; [2017]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; hydropower; frequency control; governors; power system stability; inertia; primary control; Engineering Science with specialization in Science of Electricity; Teknisk fysik med inriktning mot elektricitetslära;

    Abstract : Variations in the electricity consumption and production connected to the power system have to be balanced by active control. Hydropower is the most important balancing resource in the Nordic system, and will become even more important as the share of variable renewable energy sources increases. READ MORE

  2. 2. Modelling of cavity partial discharges at variable applied frequency

    University dissertation from Stockholm : KTH

    Author : Cecilia Forssén; KTH.; [2008]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; partial discharges; measurements; modelling; variable frequency; cavities; disc-shaped; polycarbonate; TECHNOLOGY Electrical engineering; electronics and photonics Electric power engineering; TEKNIKVETENSKAP Elektroteknik; elektronik och fotonik Elkraftteknik;

    Abstract : The presence of partial discharges (PD) in high voltage components is generally a sign of defects and degradation in the electrical insulation. To diagnose the condition of high voltage insulation, PD measurements is commonly used. READ MORE

  3. 3. Partial Discharges Studied with Variable Frequency of the Applied Voltage

    University dissertation from Stockholm : KTH

    Author : Hans Edin; KTH.; [2001]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; diagnostic methods; partial discharges; phase resolved; variable frequency; dielectric spectroscopy; dielectric response; harmonics; insulation; TECHNOLOGY Electrical engineering; electronics and photonics; TEKNIKVETENSKAP Elektroteknik; elektronik och fotonik;

    Abstract : This thesis concerns partial discharge (PD) diagnostics withvariable frequency of applied voltage in the frequency range 1mHz - 400 Hz. The exploration of a new type of spectroscopythat combines partial discharge analysis and dielectricresponse is demonstrated. READ MORE

  4. 4. Frequency Response by Wind Farms in Islanded Power Systems with High Wind Power Penetration

    University dissertation from Stockholm : KTH

    Author : Mattias Persson; [2015]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Synthetic inertia; rate of change of frequency; inertia emulation; variable speed wind turbine; frequency control;

    Abstract : The integration of variable speed wind turbines (VSWT) in power systems keep increasing inorder to reduce the emission of green house gases. This increase of power electronic converterinterfaced generation causes a decrease of power system inertia and issues previously existingin power systems tend to become more complicated and new solutions should be evaluated. READ MORE

  5. 5. High frequency electronic packaging and components : characterization, simulation, materials and processing

    University dissertation from Institutionen för teknik och naturvetenskap

    Author : Christian Johansson; Linköpings universitet.; Linköpings universitet.; [2007]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Dielectric loss; high frequency electrical characterization; microwave circuits; multilayer thin film technology; ORMOCER®; permittivity; printed diode; sequential build-up; silicone elastomer; TECHNOLOGY Information technology Signal processing; TEKNIKVETENSKAP Informationsteknik Signalbehandling;

    Abstract : Electronic packaging continues to move towards improved performance and lower cost. Requirements of higher performance, reduced size, weight and cost of both high density interconnects and high frequency devices have led to the search for new materials, material combinations, methods, processes and production equipment. READ MORE