Sökning: "Power flow"

Visar resultat 11 - 15 av 709 avhandlingar innehållade orden Power flow.

1. 11. Grease lubrication mechanisms in bearing seals

   Författare :Pieter Baart; Richard F. Salant; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Maskinelement; Machine Elements;

   Sammanfattning : Rolling bearings contain seals to keep lubricant inside and contaminants outside the bearing system. These systems are often lubricated with grease; the grease acts as a lubricant for the bearing and seal and improves the sealing efficiency. In this thesis, the influence of lubricating grease on bearing seal performance is studied. LÄS MER

3. 12. Convex Optimal Power Flow Based on Second-Order Cone Programming: Models, Algorithms and Applications

   Författare :Zhao Yuan; Mohammad Reza Hesamzadeh; Mario Paolone; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Optimal Power Flow; Second-Order Cone Programming; Distribution Locational Marginal Pricing; Wind Power; Super Grid; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : Optimal power flow (OPF) is the fundamental mathematical model to optimally operate the power system. Improving the solution quality of OPF can help the power industry save billions of dollars annually. Past decades have witnessed enormous research efforts on OPF since J. LÄS MER

4. 13. Control of Dynamically Assisted Phase-shifting Transformers

   Författare :Nicklas Johansson; Hans-Peter Nee; Olof Samuelsson; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Thyristor Controlled Series Capacitor; Thyristor Switched Series Capacitor; Controlled Series Compensator; Dynamic Power Flow Controller; Phase-Shifting Transformer; Power Oscillation Damping; Transient Stability; Power Flow Control; Adaptive Control; Electric power engineering; Elkraftteknik;

   Sammanfattning : In this thesis, controllers for power oscillation damping, transient stability improvement and power flow control by means of a Controlled Series Compensator (CSC) and and a Dynamic Power Flow Controller (DPFC) are proposed. These devices belong to the group of power system components referred to as Flexible AC Transmission System (FACTS) devices. LÄS MER

5. 14. A Study of Using Pulsed Neutron Activation for Accurate Measurements of Water Flow in Pipes

   Författare :Per Lindén; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; pulsed neutron activation; turbulent flow; neural networks; pipe flow; flow measurements; eddy diffusion; time averaging;

   Sammanfattning : The objectives of this work were 1) to investigate the performance of the pulsed neutron activation (PNA) method for determination of mass flow of water in pipes, and 2) to improve the accuracy such that an error less than 1% become possible with the PNA method. The ultimate purpose is to develop this method into a high-accuracy portable and non-intrusive flow-meter that easily can be used as a calibration tool at a number of field applications, e. LÄS MER

7. 15. Simulation of individual cells in flow

   Författare :Lailai Zhu; Luca Brandt; Michael Graham; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Hydrodynamic interaction; swimming microorganisms; capsule; Stokes flow; finite element method; boundary integral method; general geometry Ewald method; spectral element method; viscoelastic fluid; cellular deformation; flow cytometry; cell sorting; microrheology; Teknisk mekanik; Engineering Mechanics;

   Sammanfattning : In this thesis, simulations are performed to study the motion ofindividual cells in flow, focusing on the hydrodynamics of actively swimming cells likethe self-propelling microorganisms, and of passively advected objects like the red bloodcells. In particular, we develop numerical tools to address the locomotion ofmicroswimmers in viscoelastic fluids and complex geometries, as well as the motion ofdeformable capsules in micro-fluidic flows. LÄS MER