Search for dissertations about: "thermal breakdown"

Showing result 1 - 5 of 52 swedish dissertations containing the words thermal 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. Thermal conductivity of wide and ultra-wide bandgap semiconductors

   Author : Dat Tran; Plamen Paskov; Vanya Darakchieva; Martin Kuball; Linköpings universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; III-nitrides; β-Ga2O3; Thermal conductivity; Thermal transport;

   Abstract : This PhD thesis presents experimental and theoretical studies of the thermal conductivity of wide and ultra-wide bandgap semiconductors including GaN, AlN, β-Ga2O3 binary compounds, and AlxGa1−xN, ScxAl1−xN, YxAl1−xN ternary alloys. Thermal conductivity measurements are conducted using the transient thermoreflectance (TTR) technique and the results are interpreted using analytical models based on the solution of the Boltzmann transport equation (BTE) within the relaxation time approximation (RTA). READ MORE

5. 3. Theoretical and Experimental Studies of the Formation of Ionized Gases in Spark Ignition Engines

   Author : Raymond Reinmann; Förbränningsfysik; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Thermal Ionization; Calorimetry; Interferometry; Spark Ignition Engine; Current and Voltage Measurements; Engine Control.; fluid dynamics; Gases; plasmas; Gaser; plasma; fluiddynamik; Breakdown; Arc; Glow; Flame Ionization; Chemi-Ionization; Spark; Townsend; Fysicumarkivet A:1998:Reinmann;

   Abstract : The processes that govern the formation, existence and consumption of ions in gases have been studied both experimentally and theoretically. The aim of the work is targeted at increasing the understanding of these phenomena in the working gases inside an engine. READ MORE

6. 4. Thermal conductivity of AlXGa1-XN and β-Ga2O3 semiconductors

   Author : Dat Tran; Plamen Paskov; Vanya Darakchieva; Mattias Thorshell; Linköpings universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES;

   Abstract : For the high-power (HP) electronic applications the existing Si-based devices have reached the performance limits governed by the material properties. Hence the device innovation itself is unable to enhance the overall performance. READ MORE

7. 5. Fabrication and Characterization of Silicon Carbide Power Bipolar Junction Transistors

   Author : Hyung-Seok Lee; Carl-Mikael Zetterling; Tat-Sing Chow; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; silicon carbide; power device; BJT; current gain; specific on resistance RSP_ON ; breakdown voltage; forward voltage drop; surface recombination; ohmic contact.; Electrical engineering; electronics and photonics; Elektroteknik; elektronik och fotonik;

   Abstract : Silicon carbide bipolar junction transistors (BJTs) are attractive power switching devices because of the unique material properties of SiC with high breakdown electric field, high thermal conductivity and high saturated drift velocity of electrons. The SiC BJT has potential for very low specific on-resistances and this together with high temperature operation makes it very suitable for applications with high power densities. READ MORE