Search for dissertations about: "direct drive"

Showing result 21 - 25 of 112 swedish dissertations containing the words direct drive.

2. 21. Wind Turbine Drive Train System Dynamics ; Multibody Dynamic Modelling and Global Sensitivity Analysis

   Author : Saeed Asadi; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Global sensitivity analysis; Model validation; Multibody dynamics system mod-elling; Gearbox modelling; Kinematic constraints; Bearing defects detection; Wind turbine drive train dynamics; Floating reference frame;

   Abstract : To facilitate the design and production of highly efficient and reliable wind turbine drive trains, this thesis deals with the mathematical modelling and analysis of drive train system dynamics. The drive train is considered as the subsystem of the wind turbine that transfers mechanical power from the rotor hub to the generator, and thereby plays an important role in the system dynamics and the efficiency of wind turbine operation. READ MORE

4. 22. Direct Drive Bone Conduction Stimulation: Experimental Studies on Functionality and Transmission with Focus on the Bone Conduction Implant

   Author : Cristina Rigato; Chalmers tekniska högskola; []
   Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; vibrations; audiological tests; Bone Anchored Hearing Aids; Bone Conduction; comparative study; Bone Conduction Implant; transcutaneous;

   Abstract : Sound is conducted to the inner ear in two ways: by air and by bone. Air conduction (AC) hearing consists of sound waves entering the ear canal and reaching the cochlea, the main hearing organ, via the middle ear. In bone conduction (BC) hearing, instead, the transmission is through soft tissues and bone. READ MORE

5. 23. Synchronous Reluctance Machine (SynRM) in Variable Speed Drives (VSD) Applications

   Author : Reza Rajabi Moghaddam; Chandur Sadarangani; Alfredo Vagati; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Synchronous Reluctance Machine SynRM ; Torque; Torque Ripple; Design; Optimization; FEM; Control; Standard Size; Measurement; Performance Comparison; Induction Machine IM ; Interior Permanent Magnet Machine IPM ; Variable Speed Drive VSD ; General Purpose GP ; Field Oriented Control FOC ; Direct Torque Control DTC ; Heat Run; Test; Thermal; Operation Diagram; Circle Diagram; Electrical engineering; Elektroteknik;

   Abstract : This thesis is comprehensively dedicated to the theoretical and experimental reevaluation of the Synchronous Reluctance Machine (SynRM). A simple approach to derive the SynRM main characteristics and behavior is followed. An introduction to an evaluation of the different control strategies in is given. READ MORE

6. 24. Direct Numerical Simulations of Low Temperature Combustion in IC Engine Related Conditions

   Author : Fan Zhang; Strömningsteknik; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Abstract : This thesis deals with direct numerical simulation (DNS) of low temperature combustion in internal combustion engine related conditions. In particular, HCCI (homogeneous charge compression ignition), SACI (spark assisted ho-mogeneous charge compression ignition) and PPC (partially premixed charge combustion) were investigated to gain deeper understanding on the details of the combustion process. READ MORE

7. 25. On the Design of Ultra-fast Electro-Mechanical Actuators

   Author : Ara Bissal; Göran Engdahl; Torbjörn Lembke; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electro-mechanical drive; Circuit breakers; HVDC transmission; Eddy currents; Finite element; Electromagnetic; Thermal; Mechanical; Coils; Armature; Image motion analysis.;

   Abstract : The continuously increasing demand for connecting electric grids with remote renewable energy sources such as wind power and photovoltaic cells has rekindled interest in high voltage direct current (HVDC) multi-terminal networks. Although HVDC networks have numerous benefits, their adoption relies entirely on the availability of HVDC circuit breakers which, compared to traditional alternating current circuit breakers, have to operate in a time frame of milliseconds. READ MORE