Search for dissertations about: "arbitrary voltage waveforms"

Found 5 swedish dissertations containing the words arbitrary voltage waveforms.

2. 1. 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

4. 2. Partial Discharge Analysis of Stator Insulation at Arbitrary Voltage Waveform Stimulus

   Author : Xiaolei Wang; Hans Edin; Joachim Holböll; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electrical Engineering; Elektro- och systemteknik;

   Abstract : Partial discharge (PD) detection is a powerful tool to diagnose the defects and degradation in high voltage electrical insulation systems. It can be performed in both on-line and off-line conditions. READ MORE

5. 3. Arbitrary Waveform Impedance Spectroscopy for Characterization and Diagnostics of High Voltage Insulation

   Author : Björn Sonerud; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; insulation testing; aging; monitoring; discrete Fourier transforms; Dielectric measurements; dielectric materials;

   Abstract : In high voltage engineering the dielectric response technique is a widely used tool both for characterization of insulation materials and for diagnostics of components such as transformers and cables. Currently available techniques are not capable of measuring on-line which would be advantageous; when characterizing a material and evaluating the effect of different voltage magnitudes, waveforms and temperatures it is desirable to be able to observe the continuous development of the dielectric properties. READ MORE

6. 4. Partial discharges studied by dielectric response method

   Author : Xiangdong Xu; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; frequency domain spectroscopy; AWIS; partial discharge excess current; dielectric characterization; partial discharge; non-PD excess current;

   Abstract : The increasing demand of integrating various renewable energy recourses in power system requires extensive use of power electronic solutions, which allows energy conversion between different frequencies and stabilizes the system. Consequently, other than the traditional 50/60 Hz sinusoidal voltage stresses act on the high voltage insulation systems. READ MORE

7. 5. Enhancements in Dielectric Response Characterization of Insulation Materials

   Author : Xiangdong Xu; Chalmers tekniska högskola; []
   Keywords : 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;

   Abstract : 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. READ MORE