Search for dissertations about: "variable power factor"

Showing result 1 - 5 of 30 swedish dissertations containing the words variable power factor.

2. 1. Study of Induction Machines with Rotating Power Electronic Converter

   Author : Yanmei Yao; Chandur Sadarangani; Zi-Qiang Zhu; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Brushless induction machine; efficiency improvement; optimum efficiency; rotating power electronic converter; unity power factor; variable power factor; wound rotor induction machine; Electrical Engineering; Elektro- och systemteknik;

   Abstract : This thesis investigates a novel induction machine topology that uses a rotating power electronic converter. Steady-state and dynamic performance of the topology is studied to understand its operational principle. Furthermore the potential of improving its efficiency and power factor is investigated. READ MORE

4. 2. Wind Power - Added Value for Network Operation

   Author : Nayeem Ullah; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; torsional oscillation; reactive power ancillary service; voltage stability; power system simulator.; STATCOM; non-minimum phase system; Variable speed wind turbine; frequency control; sensitivity analysis; transient stability; small-signal stability;

   Abstract : This dissertation deals with the investigation on different value added properties of variable speed wind turbines (VSWT) that stem from the flexible controllability of converter interfaced wind turbines (WT). Improvements in voltage and transient stability of a nearby grid, small-signal stability improvement on the power system, frequency control support for the network operation, as well as thetechnical and the economic issues related to the reactive power ancillary service provision, are among the issues covered. READ MORE

5. 3. Dampening variation in the European Wind Energy System

   Author : Lina Reichenberg; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; variable renewables; electricity generation; geographic allocation; large-scale penetration of wind power; wind power;

   Abstract : In a future European electricity system, wind power and other variable renewables may constitute a large share of electricity production. This prospect calls for measures to manage the inherent variability of wind power, such as demand-side management, storage, and flexibility of other generation. READ MORE

6. 4. Market structure and market power : the case of the Swedish forest sector

   Author : Mats Bergman; Umeå universitet; []
   Keywords : SAMHÄLLSVETENSKAP; SOCIAL SCIENCES;

   Abstract : The Swedish forest sector is analyzed, using methods drawing on traditional (forest) market analysis and industrial organization literature. Models based on economic theory are tested empirically with time-6eries data.Paper [1] deals with how the pulp and paper industry manages wood supply risk. READ MORE

7. 5. Negotiated knowledge positions : communication in trauma teams

   Author : Maria Härgestam; Maritha Jacobsson; Christine Brulin; Magnus Hultin; Eric Carlström; Umeå universitet; []
   Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; communication; discourse psychology; ideological dilemma; interpretative repertoires; leadership; non-verbal communication; position; power; team work; time; trauma team; trauma team training; silence;

   Abstract : Background Within trauma teams, effective communication is necessary to ensure safe and secure care of the patient. Deficiencies in communication are one of the most important factors leading to patient harm. Time is an essential factor for rapid and efficient disposal of trauma teams to increase patients’ survival and prevent morbidity. READ MORE