Sökning: "dielectric response measurement"

Visar resultat 1 - 5 av 19 avhandlingar innehållade orden dielectric response measurement.

1. 1. Enhanced Dielectric Response Methods for the Characterization of Dielectric Materials

   Författare :Jing Hao; Nathaniel Taylor; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; FDS; non-contact; dielectric response; combined AC and DC; space-charge polarization;

   Sammanfattning : Dielectric response measurement is widely used for condition assessment of high voltage equipment and for characterizing candidate materials. Measurement with high accuracy and reliability is important in all stages of the lifetime of high voltage equipment, from manufacture to replacement decision. LÄS MER

3. 2. Enhancements in Dielectric Response Characterization of Insulation Materials

   Författare :Xiangdong Xu; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; harmonic limited waveform; air reference method; contact-free electrode; geometric corrections.; frequency domain spectroscopy; Dielectric characterization;

   Sammanfattning : The increasing demand of integrating various renewable energy recourses in power system requires extensive use of power electronic solutions, such as HVDC and FACTS, as these techniques allow energy conversion between different frequencies and serves to stabilize the network. Consequently, electric stresses other than traditional 50/60 Hz sinusoidal voltage stress are acting on high voltage insulation materials. LÄS MER

4. 3. Dielectric Response and Partial Discharge Diagnostics of Insulation Systems by Utilizing High Voltage Impulses

   Författare :Roya Nikjoo; Hans Edin; Andrea Cavallini; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Dielectric Response; Transients; Transformer bushing; Oil-impregnated paper; Moisture content; Partial discharge; Surface PD; Cavity PD; Superimposed impulse; Nanoparticles; Electrical Engineering; Elektro- och systemteknik;

   Sammanfattning : In this thesis, power system transients are considered as an opportunity for development of on-line diagnostics of power components and specifically the insulation systems of power transformers and bushings.A new technique for on-line dielectric response measurement of power transformer bushings is proposed which utilizes natural transients in the power system, such as lightning and switching surges, as stimuli. LÄS MER

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

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

   Sammanfattning : 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. LÄS MER

7. 5. Analysis of dielectric response measurement methods and dielectric properties of resin-rich insulation during processing

   Författare :Anders Helgeson; KTH; []
   Nyckelord :;

   Sammanfattning : The dielectric diagnostic methods ofpolarisation/depolarisation currents and recovery voltage,which are time domain methods, and capacitance and tandmeasurements at different frequencies, which is a frequencydomain method, have been studied here. In the first part of thethesis, these measurement methods are analysed and evaluated. LÄS MER