• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 113
  • 56
  • 25
  • 21
  • 17
  • 16
  • 11
  • 6
  • 3
  • 3
  • 2
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 319
  • 77
  • 56
  • 51
  • 47
  • 31
  • 31
  • 31
  • 28
  • 27
  • 23
  • 22
  • 20
  • 18
  • 18
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Metodología mediante pruebas eléctricas a cables de media tensión con tecnología VLF (Very Low Frequency)

Quispe Palomino, Ivan Enrique January 2017 (has links)
Aclara las bases teóricas de los cables de media tensión (en especial XLPE), como son el tipo de aislamiento, parámetros, los mecanismos de degradación de los cables, etc. También realizaremos una comparación entre dos pruebas de soporte tanto en DC como en VLF, con el objetivo de demostrar que este último es la mejor elección en este tipo de pruebas y que ya los métodos tradicionales de inyección DC no son recomendables. / Tesis
2

AC/DC Testing Systems for High Voltage Power Cables

Hsu, Yu-hsiang 08 July 2008 (has links)
This thesis discusses the property of AC/DC testing systems for high voltage power cables and offers improvement to the design of AC/DC testing for high voltage power cables loops. First, the thesis analyzes the structure, and the physical and the electrical properties. The worsening level of the power cables insulation can be tested out through electrification measuring and diagnosed by spectrum analysis. Using established AC/DC testing loops, we perform High-Voltage Tests and AC Partial Discharge Test, as well as calculate Capacitance and Dissipation Factor. Besides , the thesis studies and processes data analysis according to the standard that was presented by the International Electrotechnical Commission. Finally, the thesis focuses on the noise that is produced by the high voltage reactor of the AC Resonance System, performs field measurements, and analyzes the results. Finally, the thesis proposes such as installing to spacers reduce noise to protect the safety, so as to protect the safety for the people in high voltage testing laboratory.
3

Motion of a flexible cable in a vertical plane ...

Grant, Elmer Daniel, January 1918 (has links)
Thesis (Ph. D.)--University of Chicago, 1916. / Vita. "Private edition, distributed by the University of Chicago Libraries, Chicago, Illinois."
4

Motion of a flexible cable in a vertical plane ...

Grant, Elmer Daniel, January 1918 (has links)
Thesis (Ph. D.)--University of Chicago, 1916. / Vita. "Private edition, distributed by the University of Chicago Libraries, Chicago, Illinois."
5

The design of the Cleveland-Toledo underground telephone cable project

Greenman, Ralph Norton. Noran, John Eliseus. January 1937 (has links)
Thesis (C.E.)--University of Wisconsin--Madison, 1937. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaf 84).
6

Über eine methode zur behandlung unsymmetrischer Kabelsysteme unter berücksichtigung des konzentrischen mit Bleimantel umpressten Zwei-leiter-kabels als beispiel ...

Geldermann, Arthur. January 1906 (has links)
Inaug.-diss.--Königlich technischen Hochschule in Danzig.
7

Motion of a flexible cable in a vertical plane ... /

Grant, Elmer Daniel, January 1918 (has links)
Thesis (Ph. D.)--University of Chicago, 1916. / Vita. "Private edition, distributed by the University of Chicago Libraries, Chicago, Illinois." Also available on the Internet. Also issued online.
8

Characteristics of dielectric-loaded coaxial cables.

Lau, Ming Chee January 1972 (has links)
The characteristics of all modes in the dielectric-loaded coaxial cable have been given. Reduction in attenuation by dielectric loading is possible for the dominant mode in these cables, including -cables with optimum-dimensions, if lossless or sufficiently low-loss dielectrics are used. For higher losses in the loading dielectric, higher frequencies are required to achieve attenuation reduction. No significant reduction in conductor losses can be achieved with cables whose dimensions are such that only the dominant mode can be supported. Measurements of the attenuation coefficients of several lower order modes were carried out at S-band frequencies using a resonant cavity. Experimental observations agree favorably with theory for the TM modes. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Graduate
9

The optimization of cooling of underground cable systems

Fedoroff, Vitaly L. January 1970 (has links)
A novel, idealized mathematical description is presented of the cooling process of electric power cable system by an integral liquid coolant configuration. A model is first obtained for constant fluid velocities, by the use of Laplace transform and subsequent solution of an ordinary differential equation. A simple integral expression is obtained, which is numerically integrated by the Simpson's rule. The set of curves so obtained, clearly show the delay of the temperature peak vs. the peak of the power demand. A steady state form of control is proposed. Block diagrams of two implemetations are shown. These control systems are designed to maintain the temperature of the effluent constant. An optimization algorithm based on developments given by Sage is presented. This algorithm will optimize the transfer of the cooling system from the initial condition of zero velocity to the steady state operation described above. / Applied Science, Faculty of / Electrical and Computer Engineering, Department of / Graduate
10

ELECTROMAGNETIC PERFORMANCE OF A PORTED COAXIAL CABLE SENSOR (PCCS) SYSTEM

Halevi, Cliff Hunter, 1956- January 1987 (has links)
An experimental analysis of the factors which affect the sensitivity of the Ported Coaxial Cable Sensor (PCCS) system is presented. The measured response profile of the test system is compared against variations of cable separation distance, soil conductivity and permittivity, and magnetic field intensity above the transmitter cable. These experiments show that higher conductivity and permittivity of the burial medium results in a decrease in the strength of the magnetic field above the transmitter cable, and that this results in a decrease in response number. The results of these experiments are compared with the results obtained from a theoretical analysis of a simplified model. An experimentally derived relationship between cable separation distance and response number, which is valid for all soil types, can be applied to predictably minimize variations in sensitivity, resulting in a response ratio for each cell which will not exceed 3:1.

Page generated in 0.0372 seconds