Search for dissertations about: "electrical breakdown"

Showing result 1 - 5 of 106 swedish dissertations containing the words electrical breakdown.

2. 1. Mechanisms of Electrical Ageing of Oilimpregnated Paper due to Partial Discharges

   Author : Mohamad Ghaffarian Niasar; Hans Edin; Ernst Gockenback; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; partial discharges; oil-impregnated paper; oil; transformer insulation; dielectric frequency response; breakdown strength; ion mobility; thermal ageing; electrical ageing; moisture in paper; life time; thermal breakdown.; Electrical Engineering; Elektro- och systemteknik;

   Abstract : In this thesis, partial discharge (PD) phenomenon in oil-impregnated paper (OIP) is investigated under accelerated electrical stress. The thesis is mainly focused on the characteristic of PD activity and the influence it has on the insulation properties of OIP. READ MORE

4. 2. Electrical Characterisations of Bearings

   Author : Abhishek Joshi; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Ball bearing; Equivalent circuit model; Lubricants; Bearing Capacitance; Spherical bearing; Mechanical bearing; Bearing currents; Electrical conduction; Electrical characterisation;

   Abstract : Mechanical bearings are an integral part of industry, and are used in various places in order to reduce friction between two interacting surfaces and are used to transmit power and loads. Mechanical bearings are one of the most extensively used components within the wind industry, but on the other hand they are also one of the most dominantly failing failed components. READ MORE

5. 3. Microwave Breakdown: Physics and Applications

   Author : Ulf Jordan; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; resonators; breakdown plasma; waveguides; microwave breakdown; metal wedges; HPM protection;

   Abstract : Theories for microwave breakdown in gases, with emphasis on Air, are presented in this thesis. Underlying physical processes are described together with models suitable for scientific research and technical development. READ MORE

6. 4. Microwave breakdown : physics and applications

   Author : Ulf Jordan; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; breakdown plasmas; resonators; waveguides; microwave breakdown;

   Abstract : .... READ MORE

7. 5. Numerical Simulations of Long Spark and Lightning Attachment

   Author : Liliana Arevalo; Vernon Cooray; Dan Windmar; Uppsala universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; breakdown; discharge; leader channel; lightning attachment; negative discharge; positive discharge; streamer; Electrical engineering; Elektroteknik; Engineering Science with specialization in Atmospheric Discharges; Teknisk fysik med inriktning mot atmosfäriska urladdningar;

   Abstract : The research work presented here is concerned with numerical simulations of two different electrical phenomena: Long gap electrical discharges under switching impulses and the lightning attachment process associated with positive upward leaders. The development of positive upward leaders and the progression of discharges in long gaps are attributable to two intertwined physical phenomena, namely, the leader channel and the streamer zone. READ MORE