Sökning: "frequency converter"

Visar resultat 1 - 5 av 176 avhandlingar innehållade orden frequency converter.

1. 1. Modeling and Control of Voltage Source Converters Connected to the Grid

   Författare :Michael Lindgren; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; voltage source converter; switching frequency; pulse width modulation; IGBT valve; power electronics; small-signal; L-filter; LCL-filter; transfer function; line filter; active filtering; frequency response; sampling frequency;

   Sammanfattning : This thesis deals with the modeling and control of pulse width modulated (PWM) voltage source converters connected to the grid. When voltage source converters are connected to the grid, the power quality and the dynamic performance are affected by the line filter connected between the converter and the grid, and by nonlinearities caused by the switching converter. LÄS MER

3. 2. Towards Ultimate Performance of THz Heterodyne Receivers: SIS Frequency Multiplier and Wideband Passive Components

   Författare :Hawal Marouf Rashid; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Wideband passive components; distributed SIS junction; Frequency multiplier; Frequency up-converter; Hybrids; distributed SIS frequency multiplier;

   Sammanfattning : This thesis focuses on the development of advanced components for the future wideband side band separating and / or multipixel receivers for radio-astronomy with ultimate sensitivity.In this thesis, a novel frequency multiplier based on distributed superconducting tunnel (SIS) junctions has been demonstrated for the first time, taking advantage of the extreme inherent nonlinearity of such device. LÄS MER

4. 3. Synchronous generator and frequency converter in wind turbine applications : system design and efficiency

   Författare :Anders Grauers; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; synchronous generator; frequency converter; wind turbine; avrage efficiency; losses; system design; variable speed;

   Sammanfattning : This report deals with an electrical system for variable-speed wind powerplants. It consists of a synchronous generator, a diode rectifier and athyristor inverter. LÄS MER

5. 4. A new Auxiliary Converter Topology with SiC Components for Railway Applications

   Författare :LUYU WANG; Industriell elektroteknik och automation; []
   Nyckelord :Auxiliary converter; Multilevel converter; ; Silicon Carbide transistors;

   Sammanfattning : Smaller size and lower weight are always the targets of the power electronic product development. This work introduces two new topologies of auxiliary converters which have the feature of fewer components and fewer number of energy conversion stages comparing with the conventional auxiliary converter used in railway applications. LÄS MER

7. 5. On high-frequency soft-switching DC-converters for high-voltage applications

   Författare :Per Ranstad; KTH; []
   Nyckelord :soft-switching; dc-converter; high-frequency; high-voltage;

   Sammanfattning : .... LÄS MER