The voltage and the current exist in the form of waves on a transmission line. Manual for transmission lines and substation construction. A long transmission line is defined as a transmission line with an effective length more than 250 km 150 miles. In electrical power transmission lines, the conductor arranges unequal space. Sunrise powerlink steel cap micropile foundation patent pending in this respect, there is a major difference between the design of foundations for transmission lines compared to the design of foundations for most normal civil engineering structures accordingly, the amount of literature describing design techniques for overhead line foundations is relatively small compared to the literature. Two parallel wires coaxial cable microstrip line optical fiber waveguide very high frequencies, very low loss, expensive etc. Transmission lines and em waves usb media storage type. Transmission lines and electromagnetic waves nptel. Our analysis of transmission lines will include the derivation of transmission line. Pdf transmission line shunt and series compensation with.
Transmission lines a transmission line connects a generator to a load a two port network transmission lines include physical construction. The basic definition for transposition of transmission line is to rotate the conductors which result in the conductor or a phase being moved to next physical location in a regular sequence. There are 5 types of insulators used in transmission lines as overhead insulation. Sinha, department of electrical engineering,iit kharagpur. While stay and shackle insulators are mainly used in low voltage applications. Transmission lines a transmission line is used for the transmission of electrical power from generating substation to the various distribution units. Pdf electrical design of overhead power transmission. Transmission lines different types of transmission line structures transmission line equations power flow in transmission lines appendix ece 303 fall 2006 farhan rana cornell university guided waves. Due to this, there is a general consideration that the use of microstrip transmission line at thz frequency is impractical. Unlike short transmission lines and medium transmission lines, it is no longer reasonable to assume that the line parameters are lumped.
If the line is terminated with a resistor whose value is the same as the characteristic impedance of the trace zo, the reflection coefficient is zero and there will be no. Electrical design of overhead power transmission lines. The characteristic parameters of the transmission line are. These four parameters are uniformly distributed along the whole line. For a given quantity of power transmitted, doubling the voltage will deliver the same power at only half the current. Travelling wave on transmission line is the voltage current waves which propagate from the source end to the load end during the transient condition. Introduction to em waves and various techniques of. Nptel electrical engineering high voltage dc transmission. So the voltage drops are not same as one place to another. Nptel provides elearning through online web and video courses various streams. The transmission line is made up of a conductor having a uniform crosssection along the line. Pin insulators are the earliest developed overhead insulator, but are still commonly used in power. Hon tat hui transmission lines basic theories nusece ee2011 19 6 terminated transmission line note the two coordinate systems and their relation.
Types of insulators in transmission lines electrical4u. Protection of lines or feeder august 31, 2018 february 24, 2012 by electrical4u as the length of electrical power transmission line is generally long enough and it runs through open atmosphere, the probability of occurring fault in electrical power transmission line is much higher than that of electrical power transformers and alternators. To develop models of transmission lines, we first need to determine the tl parameters. Example problem a 220kv, 150 mva, 60hz, threephase transmission line is 140 km long. Introduction and modeling of transmission line lecture 1. Description of uniform lossless transmission lines and its distributed equivalent circuit. Avik bhattacharya, assistant professor of electrical. Transit time effect on a transmission line at high frequencies. Line engineering services full detail design of hvac lines up to 765kv and hvdc up to 800kv providing support to over 31 000 km of transmission lines 220kv,275kv,400kv, 533kvhvdc, 765kv 340 000 km of distribution lines 11kv, 22kv,66kv, 88kv,2kv, busy with designs for over 8 000km of new transmission lines to be. Transmission line terminations its the end that counts. Also, the amount of attenuation is extremely small, since this is due to ro. A flexible alternating current transmission system facts is a system composed of static equipment used for the ac transmission of electrical energy.
This paper presents an analysis of the effects of shunt and series line compensation levels on the transmission line voltage profile, transferred power and transmission losses for different static. Power system generation, transmission and distribution nptel. A major section of power system engineering deals in the transmission of electrical power from one place eg. These waves travel along the line with the velocity equal to velocity of light if line losses are neglected. Gmdgeometric mean distance gmrgeometric mean radius how to calculate them. Since most of the insulation is provided by air, overhead power lines are generally the lowestcost method of transmission for large quantities of electric power. Towers for support of the lines are made of wood asgrown or laminated, steel either lattice. Transmission lines in practice objectives in this course you. Each line element has its own value, and it is not possible to concentrate or lumped them at discrete points on the line.
Here you can download the free lecture notes of electromagnetic theory and transmission lines pdf notes emtl notes pdf materials with multiple files links to download. So that a pulse will propagate down a superconducting transmission line without dispersing. It transmits the wave of voltage and current from one end to another. Introduction to transmission lines and waveguides a transmission line is a device designed to guide electrical energy from one point to another. Lecture 01 introduction and types of transmission lines nptel. Different types of transmission lines are mentioned. Transmission lines and em waves nptel online videos. Transmission lines and electromagnetic waves video. It is generally a power electronicsbased system facts is defined by the ieee as a power electronic based system and other static equipment that. Manual for transmission lines and substation construction and maintenance activities volume i best management practices. Consider a 3ph symmetrical line with distances bw phases all equal to d and solid conductor of radius r. Hello and welcome to nptel mooc, on electromagnetic wave propagation, in guided and wireless media. Power sys generation transmission distribution nptel online videos, courses iit video lectures well organized.
If the trace is shorted, the reflection coefficient is 1 and there will be a 100% reflection of the opposite sign back toward the driver. Free video lectures, nptel online courses, youtube iit videos nptel courses. Here you can download the free lecture notes of high voltage direct current transmission pdf notes hvdc pdf notes materials with multiple file linksthe high voltage direct current transmission notes pdf hvdc notes pdf. To accurately model a long transmission line we must consider the exact effect of the. High voltage direct current transmission pdf notes hvdc. Nptel video lectures, iit video lectures online, nptel youtube lectures, free video lectures, nptel online courses, youtube iit videos nptel courses. Shevgaonkar, dept of electrical engineering, iit bombay for more details on nptel visit. It is meant to enhance controllability and increase power transfer capability of the network. This energy will not travel through normal electrical wire without great losses.
So its important for power system engineers to be thorough with the mathematical modeling of how this power is transmitted. Dominance of the reactive component over resistive component. Transmission line parameter an electric transmission line has four parameters, namely resistance, inductance, capacitance and shunt conductance. Ananth krishnan is a faculty member at the department of electrical engineering in iitmadras. Power sys generation transmission distribution nptel. Pin, suspension, and strain insulators are used in medium to high voltage. Amitava dasgupta, department of electrical engineering,iit madras. It is used, for example, to transfer the output rf energy of a transmitter to an antenna. Hisspecialization is photonics and specifically plasmonics. An overhead power line is an electric power transmission line suspended by towers or poles. Are two conductors required for the transfer of em wave energy. Nptel online videos, courses iit video lectures well organized. Introduction to power system analysis nptel electrical. Lecture 2introduction to transmission lines youtube.
Dispersionless transmission lines because lo and co do not depend on frequency for a superconductor, the phase velocity is independent of frequency. High voltage is used for electric power transmission to reduce the energy lost in the resistance of the wires. Transmission lines and waveguides ebookpptpdf download. What is transposition of transmission line and features of it. Moving away from this theory, the microstrip transmission line has successfully been used to transmit the thz wave. Find materials for this course in the pages linked along the left. Lecture series on digital integrated circuits by dr. Welcome, to the nptel online certificate course on flexible ac transmission system of facts devices.
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