Search for dissertations about: "applied voltage test"

Showing result 1 - 5 of 34 swedish dissertations containing the words applied voltage test.

2. 1. Hydropower generator and power system interaction

   Author : Johan Bladh; Urban Lundin; Rafael Escarela-Perez; Uppsala universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Amortisseur windings; applied voltage test; automatic voltage regulators; damper windings; damping torque; empirical modelling; equivalent circuits; excitation control; finite element method; hydropower generators; power system restoration; power system stability; synchronous machines; self excitation; shaft torque amplification; short circuit test; single machine infinite bus; slip test; standstill frequency response test; subsynchronous oscillations; synchronising torque; synchronous generators; torsional interaction.; Engineering Science with specialization in Science of Electricity; Teknisk fysik med inriktning mot elektricitetslära;

   Abstract : After decades of routine operation, the hydropower industry faces new challenges. Large-scale integration of other renewable sources of generation in the power system accentuates the role of hydropower as a regulating resource. READ MORE

4. 2. Characterization of Electrical Insulation Exposed to Arbitrary Voltage Waveforms

   Author : Björn Sonerud; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; arbitrary voltage waveforms; partial discharge; diagnostics; dielectric response measurement; signal processing; electrical treeing; dielectric heating.;

   Abstract : The extensive use of power electronics in power systems today gives rise to other voltage waveforms than the conventional 50/60 Hz sinusoidal and consequently other types of electric stress act on high voltage insulating materials. Previous studies has shown that Pulse Width Modulated (PWM) voltages and similar waveforms increase stress in Adjustable Speed Drives (ASD) as compared with sinusoidal waveforms and it has also been shown that partial discharge (PD) activity is intensified during PWM voltages and that rise time of square like pulses affect PD inception voltage. READ MORE

5. 3. Efficient Integration of Distributed Generation in Electricity Distribution Networks - Voltage Control and Network Design

   Author : Ingmar Leisse; Industriell elektroteknik och automation; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Coordinated Voltage Control; Distributed Generation; Electricity meter; PV; Wind Power; Distribution Network;

   Abstract : Distributed generation (DG), i.e. generation connected to the low and medium voltage distribution network (DN), has been increasing a lot during recent years. Thus the traditional assumption of a unidirectional power flow and a voltage decrease along the distribution feeders is no longer valid in all operation conditions. READ MORE

6. 4. Control of Voltage and Damping in Bulk Power Systems

   Author : Mohammad Reza Safari Tirtashi; Industriell elektroteknik och automation; []
   Keywords : Voltage control; Damping control; Power system dynamics;

   Abstract : Modern power system is a complex dynamical system and one of the largest man-made systems. With recent driving forces like environmental concerns over air emissions, the modern power system is evolving towards an even more complex system. READ MORE

7. 5. Influence of Ageing on Material Properties at Interfaces in Composite Insulators

   Author : Johan Andersson; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; composite insulators; ageing; silicone rubber; salt fog test; Outdoor insulation; inclined plane test; interfaces;

   Abstract : High quality of internal interfaces in composite insulators for high voltage applications is necessary for securing durability of their functionality. Weak macroscopic interfaces between the glass fibre reinforced (FRP) epoxy core and the silicone rubber (SIR) housing, such as spots with reduced bonding or a loss of the adhesion as well as presence of foreign contaminants, can appear to have an accelerating effect on the evolution of ageing processes, though it may take years before the first signs of processes endangering the insulator function appear. READ MORE