Sökning: "load current"

Visar resultat 6 - 10 av 387 avhandlingar innehållade orden load current.

1. 6. Long-term Voltage Stability in Power Systems - Alleviating the Impact of Generator Current Limiters

   Författare :Stefan Johansson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; rotor thermal overloading; dynamic load modelling; voltage stability; field current limiter; active power rescheduling; overexcitation limiter; armature current limiter; long-term power system dynamic stability;

   Sammanfattning : The main issues in this dissertation are the behaviour of current limiters protecting synchronous generators, and the interactions that occur with other components in the power system during a voltage instability. The importance of these limiters for the voltage stability is shown both in the analysis of small models and in the simulations of larger networks. LÄS MER

3. 7. Experimental Results of a Load-Controlled Vertical Axis Marine Current Energy Converter

   Författare :Johan Forslund; Mats Leijon; Karin Thomas; Jan Sundberg; Tom Blackmore; Uppsala universitet; []
   Nyckelord :Marine Current; Vertical Axis; Load Control; ; Engineering Science with specialization in Science of Electricity; Teknisk fysik med inriktning mot elektricitetslära;

   Sammanfattning : This thesis investigates the load control of a marine current energy converter using a vertical axis turbine mounted on a permanent magnet synchronous generator. The purpose of this thesis is to show the work done in the so far relatively uncharted territory of control systems for hydro kinetic energy conversion. LÄS MER

4. 8. Studies on the Load Range of an HCCI Engine using In-Cylinder Pressure, Ion Current and Optical Diagnostics

   Författare :Andreas Vressner; Förbränningsmotorer; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ion current; knock; laser ignition; chemiluminescence imaging; LES; temperature stratification; PLIF; auto igntion; flame propagation; HCCI; diagnostics; low temperature combustion;

   Sammanfattning : Internal combustion engines are continuously developed towards decreased hazardous emissions and lower fuel consumption. The homogeneous charge compression ignition (HCCI) engine is a promising concept which combines the best features of the Diesel engine and the spark ignition (SI) engine. LÄS MER

5. 9. On methods of measuring magnetic properties of power transformers

   Författare :Claes Carrander; Göran Engdahl; Anders Bergqvist; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; No-load; magnetizing current; losses; diagnostics; delta; three-phase; power transformer; magnetic core; electrical steel; measurements; simulation; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : The core of a power transformer can weigh hundreds of tons, and represents a significant part of the total ownership cost of the transformer, in terms of both the construction cost and of the monetary cost of losses. It is therefore desirable to have a method of diagnosing the core to ensure optimal performance, and to enable the operator to plan repairs of damaged or defective cores. LÄS MER

7. 10. Soil-Steel Composite Bridges : Research advances and application

   Författare :Amer Wadi; Raid Karoumi; Lars Pettersson; Ian D. Moore; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Flexible culvert; Soil‒steel composite bridge; Sloping terrain; Swedish design method; Finite element model; Ultimate capacity; Avalanche load; Failure load; Low soil cover; Failure mechanism; Long-span; Byggvetenskap; Civil and Architectural Engineering;

   Sammanfattning : Soil-steel composite bridges are considered competitive structures being an economical alternative to similar span concrete bridges. This frequently stimulates practitioners to push their design limits and expand the different areas of application including their performance in sloping terrain. LÄS MER