Search for dissertations about: "modal analysis"

Showing result 21 - 25 of 187 swedish dissertations containing the words modal analysis.

2. 21. Development of Accurate Reduced Order Models in a Simulation Tool for Turbomachinery Aeromechanical Phenomena

   Author : Mauricio Gutierrez Salas; Björn Laumert; Paul Petrie-Repar; Damian Vogt; Carlos Martel; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; flutter; forced response; high cycle fatigue; reduced order models; ROM; craig-bampton; mistuning; tuned; mistuned; cyclic; noncyclic; craig-chang; free-interface. fixed-interface; subset nominal mode; SNM; CBMS; CCMS; CCC; CBC; FEM; CMS; modal; eigen; modeshapes; aeroelasticity; aeromechanical; tool; turbomachinery; turbine; compressor; AROMA; Energy Technology; Energiteknik;

   Abstract : Modern gas turbines are still vulnerable to vibrations when operated at certain speeds. This unstable environment can lead to high cycle fatigue (HCF) and damage several of the components inside the turbine. READ MORE

4. 22. Modal Analysis, Dynamic Properties and Horizontal Stabilisation of Timber Buildings

   Author : Ida Edskär; Helena Lidelöw; Lars Stehn; Thomas Nord; Thomas Reynolds; Luleå tekniska universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Träbyggnad; Timber Structures;

   Abstract : Engineers face new challenges as taller timber buildings are constructed. According to Eurocode 1-4, both horizontal deformations from static wind and acceleration levels shall be limited. Due to the low self-weight of wood, dynamic vibrations and acceleration levels cancause problems. READ MORE

5. 23. A Multichoice Control Strategy for a VSC-HVdc

   Author : Hector F. Latorre; Mehrdad Ghandhari; Lennart Söder; Kjetil Uhlen; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Control Lyapunov Function; Modal Analysis; Power Oscillation Damping; Transient Stability; Voltage Stability; VSC-HVdc; Electrical engineering; Elektroteknik;

   Abstract : Utilization of power electronics based controllable systems (or devices) in transmission systems has opened new opportunities for the power industry to optimize utilization of the existing transmission systems, and at the same time to keep high system reliability and security. As a member of these controllable systems, Voltage Source Converters-based High Voltage direct current (VSC-HVdc) systems have the ability to rapidly control the transmitted active power, and also to independently exchange reactive power with transmissions systems. READ MORE

6. 24. Modelling and simulation of electromagnetic audible noise generated by traction motors

   Author : Fredrik Botling; Ines Lopez Arteaga; Siv Leth; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Vibro-acoustics; Electromagnetic noise; traction motor; modal analysis; multi-physics; Vehicle and Maritime Engineering; Farkostteknik;

   Abstract : An annoying tonal noise is produced by modern electrical trains duringacceleration and deceleration. This noise is caused by electromagneticforces generating structural vibrations, especially from the traction motors. READ MORE

7. 25. Power System Damping - Structural Aspects of Controlling Active Power

   Author : Olof Samuelsson; Industriell elektroteknik och automation; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electronics and Electrical technology; controller interaction; mode controllability; mode observability; mechanical equivalent; linear differential-algebraic equations; modal analysis; active power; power system damping; electro-mechanical oscillations; Elektronik och elektroteknik; Automation; robotics; control engineering; Automatiska system; robotteknik; reglerteknik;

   Abstract : Environmental and economical aspects make it difficult to build new power lines and to reinforce existing ones. The continued growth in demand for electric power must therefore to a great extent be met by increased loading of available lines. READ MORE