Search for dissertations about: "Power Coefficient"

Showing result 1 - 5 of 133 swedish dissertations containing the words Power Coefficient.

  1. 1. Frequency response by wind farms in power systems with high wind power penetration

    University dissertation from ; Chalmers tekniska högskola; Gothenburg

    Author : Mattias Persson; [2017]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; inertia estimation; frequency control; power system stability; wind power integration; Power system; synthetic inertia;

    Abstract : The integration of variable speed wind turbines (VSWT) in power systems is increasing in order to reduce the emission of green house gases. This increase of power electronic converter interfaced generation causes a decrease of power system inertia, increasing the risk of load shedding and system frequency instability. READ MORE

  2. 2. Roller skis' rolling resistance and grip characteristics influences on physiological and performance measures in cross-country skiers

    University dissertation from Östersund : Mid Sweden University

    Author : Mats Ainegren; Mittuniversitetet.; [2012]
    Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Adjustable grip; blood lactate; centre of pressure; cycle length; cycle rate; economy; efficiency; friction coefficient; heart rate; normal force; OBLA; oxygen uptake; power; ratcheted wheel; ratings of perceived exertion; roller skis; rolling resistance; tangential force; time to exhaustion;

    Abstract : The aim of this thesis was to investigate roller ski characteristics; classical and freestyle roller skis’ rolling resistance coefficients (μR) and classical style roller skis’ static friction coefficients (μS), and to study the influence of different μR and μS on cross-country skiers’ performance and both physiological and biomechanical indices. The aim was also to study differences in skiing economy and efficiency between recreational skiers, female and male junior and senior elite cross-country skiers. READ MORE

  3. 3. Combined Electrical Power Generation using Solar and Wind

    University dissertation from ; Chalmers tekniska högskola; Gothenburg

    Author : Ingemar Mathiasson; [2017]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; wave length bands; atmospheric transmittance; energy storage; Wind turbine; wind speed; quantum dots; electrical load.; extinction coefficient; silicon solar cell; solar cell;

    Abstract : The need for systems for renewable electrical power production is enormous worldwide.This applies to systems of varying size and capacity. From small systems for household purposes up to large systems for regional purposes. If possible, all systems should be linked in a common power grid. READ MORE

  4. 4. Numerical Modelling and Statistical Analysis of Ocean Wave Energy Converters and Wave Climates

    University dissertation from Uppsala : Acta Universitatis Upsaliensis

    Author : Wei Li; Uppsala universitet.; [2016]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Wave power; Wave energy converter; Gravity-based foundation; Power absorption; Wave spectrum; Linear generator; Frequency domain; Wave climate; Ocean wave modelling; Mixed-distribution model; Bivariate distribution; Archimedean copula;

    Abstract : Ocean wave energy is considered to be one of the important potential renewable energy resources for sustainable development. Various wave energy converter technologies have been proposed to harvest the energy from ocean waves. This thesis is based on the linear generator wave energy converter developed at Uppsala University. READ MORE

  5. 5. Gear tribology : friction and surface topography

    University dissertation from Göteborg : Chalmers university of technology

    Author : Li Xiao; Högskolan i Halmstad.; [2005]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TECHNOLOGY; TEKNIKVETENSKAP; Friction; Surface topography; Toughness; Lay; Gears; Power transmission; surface topography; lay; toughness; power transmission; wfficiency; gears; friction;

    Abstract : The quest for energy efficiency leads to the development of highly efficient power transmissions for vehicles. Gears are some of the most rugged and durable torque transmitters among machine elements. Friction between sliding surfaces at gear teeth is one major source of power loss. READ MORE