A New Approach to Calculation of Lightning Performance of Transmission Lines-Ii

The lightning performance of overhead transmission lines is related to the surge impedance and wave propagation time of the line towers. Theoretical and experimental studies show that present models for the tower response are not adequate. New theoretical models for tower surge impedance are presented and supported with experiments. Le comportement des lignes de transmission aeriennes contre la foudre est fonction de l'impedance caractiristique et du temps de propagation des antennes de transmission. Des etudes th£oriques et experimentales indiquent que, en ce qui concerne la reponse des antennes, les modeles presents ne sont pas adequats. De nouveaux modeles theoriques pour Pimp£dance caracte>istique des antennes sont prSsentes et appuyes d'experiences. a TDR RESULT cn X LU 200 CJ z < Q LU CL t-H 150

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“…2 at t = 2hlc to give the maximum tower impedance. 4 Both models use Eq. 3 for the tower wave propagation time.…”

Section: Previous Models For Tower Impedancementioning

confidence: 99%

Surge response of transmission towers

Chisholm

Chow²,

Srivastava³

1982

Can. Electr. Eng. J.

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“…Algunos autores han propuesto obtener la impedancia de la torre en función de la geometría y de la forma de onda ingresada, fundamentando su análisis en modelos verticales y horizontales de geometrías cilíndricas conocida como la ecuación de Jordan (Jordan, 1934) o la de Wagner-Hileman (Wagner, 1959;1961), y con modelos cónicos como el propuesto por Sargent-Darveniza (Sargent, 1967;1969). Otros autores, aproximaron la impedancia de la torre por medio de geometrías equivalentes (IEEE, 1997), proponiendo expresiones para obtener el valor de la impedancia de las torres a partir de modelos simples (cilíndricos y cónicos), aplicados a diferentes configuraciones de torres según el nivel de tensión eléctrica.…”

Section: Introductionunclassified

Análisis de Sensibilidad Computacional de la Respuesta en Frecuencia de la Impedancia de Torres de Transmisión

2016

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ResumenSe determina a través del Modelo Hibrido Electromagnético la respuesta en frecuencia de la impedancia vista desde el conductor de guarda. El modelo considera variaciones en la geometría de dos torres; la puesta a tierra y la resistividad del suelo. La evaluación de transitorios electromagnéticos en líneas de transmisión involucra diferentes elementos siendo las torres uno de los que más podría influenciar la magnitud y forma de onda de los transitorios generados. La respuesta en frecuencia presenta un comportamiento predominantemente inductivo en el rango de frecuencia analizado, razón por la cual fue ajustada a la expresión de impedancia de un circuito serie resistivo-inductivo-capacitivo en términos de transformadas de Laplace, obteniéndose valores de inductancia en el rango de lo reportado en la literatura técnica. Palabras clave: transitorios electromagnéticos; impedancia; torres de transmisión; puesta a tierra; respuesta en frecuencia Computational Sensitivity Analysis of the Impedance Frequency Response of Power Transmission Towers AbstractThe frequency response of the impedance seen from the top of two towers by the Hybrid Electromagnetic Model is determined. The model considers variations in the geometry of the towers, geometry of grounding system, and soil resistivity. The evaluation of electromagnetic transients in transmission lines involves different components being towers the elements that can further influence the magnitude and wave shape of the generated transient. The frequency response shows a predominantly inductive behavior. For that reason, frequency response is fitted to impedance expressions of a series-inductivecapacitive circuit in terms of Laplace transform, obtaining inductance values in ranges similar to values reported in the literature.

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“…

\frac{dv}{dx} = - Z (x) \cdot i, \frac{di}{dx} = - Y (x) \cdot v

The above relation is applied to vertical conductors, inclined (to earth) conductors, and nonparallel conductors . In this paper, nonuniform conductors are defined as those whose impedance and admittance are a function of the position along the conductor . To derive accurate formulas for the impedances and admittances of nonuniform conductors, it is quite common to apply an image theory based on transverse electromagnetic (TEM) mode wave propagation .…”

Section: Introductionmentioning

confidence: 99%

A study of transient responses on nonuniform conductors by FDTD simulations

Asada

Ametani

Baba

et al. 2016

IEEJ Transactions Elec Engng

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Surge propagation on nonuniform conductors has been investigated on the basis of finite-difference time-domain (FDTD) simulations. It has been confirmed that an inclined conductor above the earth is represented following the image theory based on transverse electromagnetic (TEM) wave propagation by two angled (nonparallel) conductors in a free space. Nonparallel conductor systems above the earth show a wave propagation characteristic quite different from that of the TEM mode, and thus steady-state and transient phenomena on the nonparallel conductors cannot be appropriately analyzed by a circuit theory and by simulation tools such as the EMTP based on the circuit theory.

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A New Approach to Calculation of Lightning Performance of Transmission Lines-Ii

Cited by 39 publications

References 15 publications

Surge response of transmission towers

Surge response of transmission towers

Análisis de Sensibilidad Computacional de la Respuesta en Frecuencia de la Impedancia de Torres de Transmisión

A study of transient responses on nonuniform conductors by FDTD simulations

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