Sökning: "low voltage cable"

Visar resultat 21 - 25 av 31 avhandlingar innehållade orden low voltage cable.

1. 21. Transmission line theory for cable modeling: a delay-rational model based on Green's functions

   Författare :Maria De Lauretis; Sven Nordebo; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Industriell elektronik; Industrial Electronics;

   Sammanfattning : At present, induction motors are controlled via the so-called variable-frequency drives (VFD) that allow to control the speed for the motors. The purpose of this PhD thesis is to improve electromagnetic modeling techniques for the study of conducted electromagnetic emissions in variable-frequency drives, with the aim of enhancing their reliability in energy production plants. LÄS MER

3. 22. Electromagnetic dispersion modeling and analysis for HVDC power cables

   Författare :Stefan Gustafsson; Sven Nordebo; Martin Norgren; Linnéuniversitetet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; HVDC power cables; electromagnetic model; TDR measurement; sensitivity analysis; dispersion relation; propagation constant; low-frequency asymptotics;

   Sammanfattning : Derivation of an electromagnetic model, regarding the wave propagation in a very long (10 km or more) High Voltage Direct Current (HVDC) power cable, is the central part of this thesis. With an existing “perfect” electromagnetic model there are potentially a wide range of applications. LÄS MER

4. 23. Data analytics for weak spot detection in power distribution grids

   Författare :Hassan Mashad Nemati; Sławomir Nowaczyk; Anita Pinheiro Sant'Anna; Math Bollen; Högskolan i Halmstad; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : This research aims to develop data-driven methods that extract information from the available data in distribution grids for detecting weak spots, including the components with degraded reliability and areas with power quality problems. The results enable power distribution companies to change from reactive maintenance to predictive maintenance by deriving benefits from available data. LÄS MER

5. 24. Numerical Modelling of Transients in Electrical Systems

   Författare :Mihael Zitnik; Marcos Rubinstein; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physics; Fysik; Physics; Fysik; Electricity; Esp The Study Of Transients and Discharges; elektricitetslära; ssk studiet av transienter och urladdning;

   Sammanfattning : This thesis deals with the numerical modelling of the response of electrical systems to transient surge voltages and currents caused by lightning. Electrical systems, when subjected to high amplitude transients behave in ways very different from its behaviour under normal operating conditions. LÄS MER

7. 25. Intentional electromagnetic interference (IEMI) : Susceptibility investigations and classification of civilian systems and equipment

   Författare :Daniel Månsson; Rajeev Thottappillil; Mats Bäckström; William Radasky; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electromagnetic compatibility; Intentional electromagnetic interference; High power electromagnetic; Other engineering physics; Övrig teknisk fysik;

   Sammanfattning : This PhD thesis addresses the threat posed to society by sources that can produce high power electromagnetic pulses (HEPM) and be used maliciously to disturb or damage electronic equipment. The vulnerability from intentional electromagnetic interference (IEMI) has increased in the recent decades due to the widespread dependence of the civil society on sensitive electronic systems and proliferation of radiation sources. LÄS MER