Sökning: "Current and Voltage Measurements"

Visar resultat 1 - 5 av 182 avhandlingar innehållade orden Current and Voltage Measurements.

1. 1. Grid-Connected Voltage Source Converter - Control Principles and Wind Energy Applications

   Författare :Jan Svensson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; wind turbine; voltage source converter; voltage angle control; frequency response; vector current control; grid-connected; forced-commutated; measurements;

   Sammanfattning : The thesis focuses on a forced-commutated voltage source converter (VSC) connected to a grid in a wind energy application. The work consists of four parts. The first part addresses the type of electrical system which should be used in a wind turbine. LÄS MER

3. 2. EMC in railway systems : measurements, modeling and analysis

   Författare :Stefan Niska; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Drift och underhållsteknik; Operation and Maintenance;

   Sammanfattning : The subject of this study and resulting thesis was to investigate the electromagnetic compatibility (EMC) problems in the multi-electrical signaling circuitry along a railway track. These signaling systems have been expanding over time from buried multi-wired electrical copper cables to optical fiber cables, sometimes located parallel to the contact line in the catenaries. LÄS MER

4. 3. Expanding the versatility and functionality of iontronic devices

   Författare :Dennis Cherian; Magnus Berggren; Daniel T Simon; Klas Tybrandt; Alon Gorodetsky; Linköpings universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : Biological systems rarely use electrons as signal regulators, most of the transport and communication in these system utilize ions. The discovery of conjugated polymers and polyelectrolytes and their unique properties of mixed ionic electronic properties opened the possibility of using these in the domain of bioelectronics, which paved the way for the field of organic bioelectronics. LÄS MER

5. 4. Growth and characterization of SiC and GaN

   Författare :Rafal Ciechonski; Erik Janzén; Sebastian Lourdudoss; Linköpings universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; SiC; GaN; Deep level transient spectroscopy; Minority Carrier Transient Spectroscopy; Hall effect; Cathodoluminescence; Scanning electron microscopy; Atomic Force microscopy; sublimation growth; MOCVD; heterostructures; High Electron Mobility transistor; point defects; Material physics with surface physics; Materialfysik med ytfysik;

   Sammanfattning : At present, focus of the SiC crystal growth development is on improving the crystalline quality without polytype inclusions, micropipes and the occurrence of extended defects. The purity of the grown material, as well as intentional doping must be well controlled and the processes understood. LÄS MER

7. 5. On the Zero and Low Field Vortex Dynamics : An Experimental Study of Type-II Superconductors

   Författare :Örjan Festin; Peter Svedlindh; Piero Martinoli; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Engineering physics; high temperature superconductors; thermal fluctuations; YBCO; MgB2; anisotropic superconductors; vortex dynamics; Kosterlitz-Thouless transition; current voltage characteristics; complex conductivity; Flux noise; Teknisk fysik; Engineering physics; Teknisk fysik;

   Sammanfattning : Dynamic properties of type-II superconductors have been experimentally studied in zero and low magnetic fields using SQUID magnetometry and I–V measurements.In zero magnetic field close to the critical temperature, the physical properties of type-II superconductors are dominated by spontaneously created vortices. LÄS MER