Search for dissertations about: "marley"

Showing result 1 - 5 of 8 swedish dissertations containing the word marley.

2. 1. On The Initiation of Upward Positive Leader Discharges During Lightning Strikes

   Author : Marley Becerra; Uppsala universitet; []
   Keywords : TECHNOLOGY; TEKNIKVETENSKAP;

   Abstract : .... READ MORE

4. 2. On the Attachment of Lightning Flashes to Grounded Structures

   Author : Marley Becerra; Vernon Cooray; Rajeev Thottappillil; Mats Boman; Ivo Gallimberti; Uppsala universitet; []
   Keywords : Engineering physics; Lightning; Lightning attachment; Positive leader discharges; Lightning protection; Thunderstorms; Numerical modeling; Teknisk fysik;

   Abstract : This thesis deals with the physical modeling of the initiation and propagation of upward positive leader discharges from grounded structures during lightning strikes. It includes the analysis of upward leaders initiated under the influence of the electric field produced by a dominant negative cloud charge and due to the combined action of a negative thundercloud and a descending downward stepped negative leader. READ MORE

5. 3. Pre-breakdown Phenomena in Mineral Oil Based Nanofluids

   Author : Mauricio Aljure; Marley Becerra Garcia; Øystein Leif Gurandsrud Hestad; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electrical Engineering; Elektro- och systemteknik;

   Abstract : Mineral oil is a dielectric liquid commonly used in high voltage equipment such as power transformers. Interestingly, it has been experimentally observed that the dielectric strength of the mineral oil is improved when nanoparticles are added. READ MORE

6. 4. On the inception and propagation of streamers along mineral-oil/solid interfaces

   Author : David Ariza; Marley Becerra; Olivier Lesaint; KTH; []
   Keywords : ;

   Abstract : This thesis presents an experimental study of positive and negativestreamers propagating along mineral-oil/solid interfaces under square highvoltage pulses. The thesis includes the design and construction of anexperimental setup to studying the streamers in a point-plane configurationcapable to detect streamer parameters such as velocity, length, propagationtime, emitted light and charge. READ MORE

7. 5. Enhanced Active Resonant DC Circuit Breakers for HVDC Grids

   Author : Tim Augustin; Hans-Peter Nee; Marley Becerra; Jürgen Biela; KTH; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Active damping; Actuator; DC circuit breakers; DC grid; DC power systems; Fast mechanical switch; Fault handling strategy; Gas discharge devices; HVDC; HVDC circuit breakers; Multilevel converters; Multiterminal HVDC; Power transmission; Spark gaps; Thomson-coil actuator; Vacuum interrupter; Voltage Source Converter VSC ; Electrical Engineering; Elektro- och systemteknik;

   Abstract : High-voltage DC (HVDC) grids are considered promising for the electricity grid expansion required to integrate renewable energy sources into the existing infrastructure. DC fault currents increase rapidly and lack a current zero crossing. READ MORE