Search for dissertations about: "Contra-rotating"

Found 3 swedish dissertations containing the word Contra-rotating.

  2. 1. Low head pumped hydro storage with contra-rotating pump-turbines

    Author : Jonathan Fahlbeck; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Energy storage; Pumped hydro storage; CFD; Transients; Pump-turbine; Low head; OpenFOAM; Contra-rotating; Hydropower;

    Abstract : The increasing share of electrical energy production by intermittent sources pushes the demand for energy storage. Pumped hydro storage (PHS) has a long history of providing a cost-efficient energy storage solution. However, for PHS to be a viable option, a large head is typically required. READ MORE

  4. 2. Core Loss Prediction in Hydroelectric Generators and Analysis of a Contra-Rotating Machine Topology

    Author : Martin Ranlöf; Uppsala universitet; []
    Keywords : TECHNOLOGY; TEKNIKVETENSKAP;

    Abstract : The call for increased accuracy in the process of design and analysis of electrical machines has encouraged the use of numerical methods to calculate the electric and magnetic field distributions within this type of apparatus. The finite element method is a numerical technique that has become specifically widespread and popular, due to the relative swiftness and accuracy with which it is possible to treat complex machine geometries and non-linear material characteristics. READ MORE

  5. 3. Electromagnetic Analysis of Hydroelectric Generators

    Author : Martin Ranlöf; Urban Lundin; Georg Traxler-Samek; Uppsala universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Contra-rotating rotors; damping torque; damper winding; finite element method; hydroelectric generators; permeance model; pole shoe shape; rotational losses; single machine infinite bus; slot ripple; synchronizing torque; synchronous machines; voltage waveform.; Engineering physics; Teknisk fysik; Engineering Science with specialization in Science of Electricity; Teknisk fysik med inriktning mot elektricitetslära;

    Abstract : Hydropower maintains its position as the most important source of renewable electric energy in the world. The efficiency of large hydropower plants is unsurpassed, and after more than hundred years of development, the technology is mature and highly reliable. READ MORE