Search for dissertations about: "Järnvägsgruppen - Elsystem"

Found 4 swedish dissertations containing the words Järnvägsgruppen - Elsystem.

2. 1. Concepts for Power System Small Signal Stability Analysis and Feedback Control Design Considering Synchrophasor Measurements

   Author : Yuwa Chompoobutrgool; Luigi Vanfretti; Mats Larsson; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; wide-area damping control; inter-area oscillations; power system stabilizers; PMU; Järnvägsgruppen - Elsystem; Järnvägsgruppen - Elsystem;

   Abstract : In the Nordic power network, the existence of poorly damped low-frequency inter-area oscillations (LFIOs) has long affected stability constraints, and thereby, limited power transfer capacity. Adequate damping of inter-area modes is, thus, necessary to secure system operation and ensure system reliability while increasing power transfers. READ MORE

4. 2. Analysis and Control Aspects of Brushless Induction Machines with Rotating Power Electronic Converters

   Author : Naveed ur Rehman Malik; Chandur Sadarangani; Luca Peretti; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Doubly-fed induction generator; extended vector control; induction machine; internal model control; Lindmark concept; low voltage ride through; passive resistive network; rotating power electronic converter; rotating exciter; symmetrical faults; synchronous machine; unity power factor; unsymmetrical faults; vector control; wind turbines.; Järnvägsgruppen - Elsystem; Järnvägsgruppen - Elsystem;

   Abstract : This thesis deals with the steady-state, dynamic and control aspects of new type of brushless configuration of a doubly-fed induction machine in which the slip rings and carbon brushes are replaced by rotating power electronics and a rotating exciter. The aim is to study the stability of this novel configuration of the generator under mechanical and grid disturbances for wind power applications. READ MORE

5. 3. On Gate Drivers and Applications of Normally-ON SiC JFETs

   Author : Dimosthenis Peftitsis; Hans-Peter Nee; Johann Walter Kolar; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Silicon Carbide; Normally-ON Junction Field-Effect Transistors JFETs ; Gate-Drive Circuits; Protection circuits; High-Efficiency Converters.; Järnvägsgruppen - Elsystem; Järnvägsgruppen - Elsystem;

   Abstract : In this thesis, various issues regarding normally-ON silicon carbide (SiC)Junction Field-Effect Transistors (JFETs) are treated. Silicon carbide powersemiconductor devices are able to operate at higher switching frequencies,higher efficiencies, and higher temperatures compared to silicon counterparts. READ MORE

6. 4. Vector Measurements for Wireless Network Devices

   Author : Efrain Zenteno; Peter Händel; Kristoffer Andersson; Magnus Isaksson; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Vector measurements; radio frequency; synthetic instrumentation; bandwidth extension; Järnvägsgruppen - Elsystem; Järnvägsgruppen - Elsystem;

   Abstract : Wireless networks are an iconic technology of today’s modern era, theyare present in our daily activities as can be exemplified by cellular communications,wi-fi, bluetooth, and others. Vector measurements play an importantrole in the design, simulation, and testing of wireless networks and are usedto characterize key devices operating in the radio interface, such as amplifiers,filters, and mixers. READ MORE