Sökning: "harmonics"

Visar resultat 6 - 10 av 168 avhandlingar innehållade ordet harmonics.

1. 6. Linear Time-Varying Systems: Modeling and Reduction

   Författare :Henrik Sandberg; Anders Rantzer; Alexandre Megretski; Institutionen för reglerteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; linear time-varying; model reduction; balanced truncation; error bounds; power converters; harmonics; periodic modeling; inverter locomotive; linear time-varying; model reduction; balanced truncation; error bounds; power converters; periodic modeling; harmonics; inverter locomotive;

   Sammanfattning : Linear time-invariant models are widely used in the control community. They often serve as approximations of nonlinear systems. For control purposes linear approximations are often good enough since feedback control systems are inherently robust to model errors. In this thesis some of the possibilities for linear time-varying modeling are studied. LÄS MER

3. 7. On Power Electronics Interface for Distributed Generation Applications and its Impact on System Reliability to Customers

   Författare :Fainan Magueed; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; LCL-filter; vector control; voltage dips; L-filter; power quality; voltage regulation; harmonics; distributed generation; weak grid; VSC; strong grid;

   Sammanfattning : Distributed generation (DG) is being employed as a means of achieving increased reliability for electrical power systems as regarded by consumers. As the most of DG technologies utilize renewable sources, the power electronic interface plays a vital role to match the characteristics of a DG unit with the grid requirements. LÄS MER

4. 8. Managing uncertainties through efficient calculation of transients and harmonic propagation in power systems

   Författare :Oscar Lennerhag; Math Bollen; Jan Lundquist; David Thomas; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Overvoltages; harmonics; uncertainties; stochastic methods; Electric Power Engineering; Elkraftteknik;

   Sammanfattning : The electric power system is undergoing changes including large-scale introduction of renewable energy sources together with HVDC/FACTS, changes in the network such as increased amount of high voltage cables, industrial electrification, and changes in the load composition. These changes will impact the system in different ways and lead to challenges that must be addressed to facilitate planning, dimensioning, and operation of the system in a secure and economical way. LÄS MER

5. 9. Improving the functionality of synchronous machines using power electronics

   Författare :Fredrik Evestedt; Urban Lundin; C. Johan. D. Abrahamsson; Jon Kjellin; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Power electronics; Synchronous machines; Excitation systems; Magnetic thrust bearing; Starting synchronous machines; Split rotor; Rotating electronics; Magnetic fields; Measurement systems; Unbalanced magnetic pull; Harmonics; Engineering Science with specialization in Science of Electricity; Teknisk fysik med inriktning mot elektricitetslära;

   Sammanfattning : With the advent of modern power electronics there is reason to explore what can be achieved when it is applied to a mature technology like synchronous machines. In this text several concepts will be presented on how it is possible to control forces and how to get better performance out of synchronous machines by using power electronics. LÄS MER

7. 10. Some problems concerning spherical harmonics

   Författare :Einar Hille; Stockholms högskola; []
   Nyckelord :;

   Sammanfattning : .... LÄS MER