Sökning: "high-frequency switching"

Visar resultat 16 - 20 av 43 avhandlingar innehållade orden high-frequency switching.

1. 16. Utilization of Decomposition Techniques for Analyzing and Characterizing Flows

   Författare :Christian Carlsson; Strömningsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Decomposition techniques; Proper orthogonal decomposition; Dynamic mode decomposition; Extended dynamic mode decomposition; Swirl switching; Swirling flow; Low swirl burner; Fluid-structure interaction;

   Sammanfattning : This thesis presents the utilization of two different decomposition techniques, proper orthogonal decomposition (POD) and dynamic mode decomposition (DMD), for enhanced understanding of flow structures and their stability. The advantages of these techniques are shown for a range of flow situations, most of which are turbulent. LÄS MER

3. 17. Integrated Compact Drives for Electric and Hybrid Electric Vehicles

   Författare :Lebing Jin; Hans-Peter Nee; Staffan Norrga; Oskar Wallmark; Robert Pilawa-Podgurski; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; distributed control; electric vehicle; energy storage capability; integrated motor drive; modular converter; modulation; power losses; stacked polyphase bridges converter; switching frequency; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : To develop more competitive solutions, one of the trends in the development of drive systems for electric and hybrid electric vehicles (EVs/HEVs) is to integrate the power electronic converter and the electric motor. This thesis aims to investigate the performance and the operation of modular converters in integrated motor drive systems for EVs/HEVs. LÄS MER

4. 18. Spin-diode effect and thermally controlled switching in magnetic spin-valves

   Författare :Sebastian Andersson; Vladislav Korenivski; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : This thesis demonstrates two new device concepts that are based on the tunneling and giant magnetoresistance effects. The first is a semiconductor-free asymmetric magnetic double tunnel junction that is shown to work as a diode, while at the same time exhibiting a record high magnetoresistance. LÄS MER

5. 19. EMI from Switched Converters – Simulation Methods and Reduction Techniques

   Författare :Andreas Henriksson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; state space methods; EMI; semiconductor device modeling; diode reverse recovery; diode modeling; conducted emissions; Semiconductor device measurements; DC DC converters;

   Sammanfattning : In this thesis, the conducted EMI from switched power converters has been analyzed using various existing models, own-derived models as well as measurements. The ingoing passive components in a switching converter have been modeled with respect to their high frequency behavior and the static and dynamic behavior of the active semiconductors has been analyzed. LÄS MER

7. 20. Electromagnetic characterization of power electronic systems

   Författare :Mathias Enohnyaket; Mats Alaküla; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Industriell elektronik; Industrial Electronics;

   Sammanfattning : Propelled by increased global awareness and demand for clean energy systems, there is a growing trend in transportation, utility, industrial, and residential applications towards the utilisation of power electronic systems with enhanced power ow controllability and eciency. Examples of power electronics applications include terminal converters in high-voltage direct Current (HVDC) transmission; exible AC transmission systems (FACTS); and converters to interface alternative energy systems such as wind turbines to the grid, variable-speed motor drives in pump systems, vehicular propulsion systems, air-conditioners, and refrigerators. LÄS MER