Search for dissertations about: "electric contacts"

Showing result 21 - 25 of 34 swedish dissertations containing the words electric contacts.

  2. 21. On the Design of Ultra-fast Electro-Mechanical Actuators

    Author : Ara Bissal; Göran Engdahl; Torbjörn Lembke; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electro-mechanical drive; Circuit breakers; HVDC transmission; Eddy currents; Finite element; Electromagnetic; Thermal; Mechanical; Coils; Armature; Image motion analysis.;

    Abstract : The continuously increasing demand for connecting electric grids with remote renewable energy sources such as wind power and photovoltaic cells has rekindled interest in high voltage direct current (HVDC) multi-terminal networks. Although HVDC networks have numerous benefits, their adoption relies entirely on the availability of HVDC circuit breakers which, compared to traditional alternating current circuit breakers, have to operate in a time frame of milliseconds. READ MORE

  4. 22. Low Temperature Charge Transport in Diamond

    Author : Viktor Djurberg; Jan Isberg; Julien Pernot; Uppsala universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Teknisk fysik med inriktning mot elektronik; Engineering Science with specialization in Electronics;

    Abstract : Diamond is a wide band semiconductor with fascinating electrical and physical properties. It has high thermal and electrical conductivity, high electrical breakdown field, high radiation hardness and is chemically inert. READ MORE

  5. 23. Synthesis and Characterization of Composite Materials for Thermoelectric Power Generation

    Author : Richard Heijl; Chalmers tekniska högskola; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Abstract : In a thermoelectric material, a temperature difference will give rise to an electric potential that is proportional to the temperature gradient. In a closed circuit, this potential can keep a current flowing as long as the temperature gradient is maintained. READ MORE

  6. 24. Active friction control by using CO2 and moisture

    Author : Jing Hua; Shi Yijun; Shah Faiz; Luleå tekniska universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; friction control; Machine Elements; Maskinelement;

    Abstract : Nowadays the demand for intelligent control of tribological interactions is strongly increasing in various applications. We often strive to minimize friction but there are also many situations where high friction is desirable. In some cases, something in between, i.e. READ MORE

  7. 25. Studies on Current Commutation in Hybrid DC-breakers

    Author : Jesper Magnusson; Göran Engdahl; Magne Runde; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Commutation; Hybrid DC-breakers; Electrical Engineering; Elektro- och systemteknik;

    Abstract : Compared to conventional AC-circuit breakers, a DC-breaker has to act fast and force the current down to zero. Many different DC-breaker topologies are available, and this thesis is focused on the hybrid DC-breaker comprising a mechanical switch and high power semiconductors. READ MORE