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Visar resultat 11 - 15 av 98 avhandlingar som matchar ovanstående sökkriterier.

1. 11. Subsynchronous Resonance in Doubly Fed Induction Generator based Wind farms

   Författare :Selam Chernet; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; generalized Nyquist criterion GNC .; Passivity; doubly-fed induction generator DFIG ; subsynchronous controller interaction SSCI ; Wind power; Impedance-based analysis; induction generator effect IGE ; subsynchronous resonance SSR ;

   Sammanfattning : The objective of this thesis is to investigate the risk for instabilities due to subsynchronous resonance (SSR) conditions in large wind farms connected to series-compensated transmission lines. In particular, the focus is on doubly-fed induction generator (DFIG) based wind farms. LÄS MER

3. 12. Subsynchronous Resonance in Doubly-Fed Induction Generator Based Wind Farms

   Författare :Selam Chernet; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Induction Generator Effect IGE ; Doubly-Fed Induction Generator DFIG ; SubSynchronous Resonance SSR ; passivity.; Wind power; impedance-based analysis; SubSynchronous Controller Interaction SSCI ;

   Sammanfattning : The objective of this thesis is to investigate the risk for instabilities due to SubSynchronousResonances (SSR) conditions in large wind farms connected to series-compensated transmissionlines. In particular, the focus is on Doubly-Fed Induction Generator (DFIG) based windfarms. LÄS MER

4. 13. Periodic Structures with Higher Symmetries: Analysis and Applications

   Författare :Fatemeh Ghasemifard; Martin Norgren; Oscar Quevedo-Teruel; Guido Valerio; Stefano Maci; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; periodic structures; higher symmetries; dispersion analysis; mode matching; generalized Floquet theorem; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : In this thesis, periodic structures with higher symmetries are studied. Their wave propagation characteristics are investigated and their potential applications are discussed. Higher-symmetric periodic structures are described with an additional geometrical operation beyond a translation operator. LÄS MER

5. 14. Measurements, Analysis Techniques and Experiments in Sound and Vibration : Applied to Operational MRI Scanners and in Remote Laboratories

   Författare :Imran Khan; Lars Håkansson; Ingvar Claesson; Josef Ström Bartunek; Gustavo R. Alves; Blekinge Tekniska Högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Active Noise Control; Remote Laboratories; Sound and Vibration Measurements; Vibration Analysis; Vibration Transmission;

   Sammanfattning : High quality noise and vibration measurements outside of a laboratory environment on real life structures and applications are not trivial. True boundary and operating conditions enforce unique challenges on the measurements. Measurements in hazardous situations such as high magnetic fields, and high temperature environments, etc. LÄS MER

7. 15. Interpretation of Railway Track Alignment Measurements in a Geodynamic Perspective

   Författare :Jonas Majala; Jan Laue; Thorkild Maack Rasmussen; Kenneth Viking; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Dynamic load; Railway; Frequency; Track measurement; Geoteknik; Soil Mechanics;

   Sammanfattning : The development in society means that infrastructure like ballasted railway systems are facing challenges due to request for increased number of high-speed trains and heavier freight trains. This implies that ballasted railways get an increased impact from larger dynamic loads. LÄS MER