02-04-2016, 08:20 PM
07-04-2016, 11:44 AM
ppt for icing of power transmission line in wikipedia
Abstract
In communications and electronic engineering, a transmission line is a specialized cable or other structure designed to carry alternating current of radio frequency, that is, currents with a frequency high enough that their wave nature must be taken into account. Transmission lines are used for purposes such as connecting radio transmitters and receivers with their antennas, distributing cable television signals, trunklines routing calls between telephone switching centres, computer network connections and high speed computer data buses.This article covers two-conductor transmission line such as parallel line (ladder line), coaxial cable, stripline, and microstrip. Some sources also refer to waveguide, dielectric waveguide, and even optical fibre as transmission line, however these lines require different analytical techniques and so are not covered by this article; see Waveguide (electromagnetism).
Introduction
This paper presents a capacitive measurement principle to detect the formation and accumulation of ice on an overhead power transmission line, for the use with an autonomous monitoring system. The proposed scheme can use either a linear or a circular type electrode geometry. Inter-electrode capacitances are measured by a capacitance-to-digital converter for linear as well as circular type electrodes, mounted on the surface of the conductor. The icing and the thickness of the ice layer can be determined by measuring the capacitances formed by the electrodes that are kept in different distances, by exploiting the time signals and differences in the permittivities of air, ice and water. A prototype system has been developed in the laboratory and test results along with finite element simulations results are presented. The test results show good agreement with the finite element analysis and the developed system successfully senses the icing of a transmission line.
Abstract
In communications and electronic engineering, a transmission line is a specialized cable or other structure designed to carry alternating current of radio frequency, that is, currents with a frequency high enough that their wave nature must be taken into account. Transmission lines are used for purposes such as connecting radio transmitters and receivers with their antennas, distributing cable television signals, trunklines routing calls between telephone switching centres, computer network connections and high speed computer data buses.This article covers two-conductor transmission line such as parallel line (ladder line), coaxial cable, stripline, and microstrip. Some sources also refer to waveguide, dielectric waveguide, and even optical fibre as transmission line, however these lines require different analytical techniques and so are not covered by this article; see Waveguide (electromagnetism).
Introduction
This paper presents a capacitive measurement principle to detect the formation and accumulation of ice on an overhead power transmission line, for the use with an autonomous monitoring system. The proposed scheme can use either a linear or a circular type electrode geometry. Inter-electrode capacitances are measured by a capacitance-to-digital converter for linear as well as circular type electrodes, mounted on the surface of the conductor. The icing and the thickness of the ice layer can be determined by measuring the capacitances formed by the electrodes that are kept in different distances, by exploiting the time signals and differences in the permittivities of air, ice and water. A prototype system has been developed in the laboratory and test results along with finite element simulations results are presented. The test results show good agreement with the finite element analysis and the developed system successfully senses the icing of a transmission line.