Analysis Of Lightning-induced Voltages Research Articles

Analysis of Lightning-Induced Voltages on a Matched Experimental Overhead Line

This article presents an analysis of 64 lightning-induced voltage waveshapes recorded on a 2.7 km long, nonenergized experimental line located on the campus of the University of São Paulo, São Paulo, Brazil. The line had two conductors separated by 6 m crossarms; one was equipped with surge arresters, whereas the other was unprotected. The data presented in this article refer to the unprotected conductor, which was matched at both ends. Although, strictly speaking, all the recorded voltages were bipolar, they were classified into four categories and the parameters which characterize each type are presented and discussed. About 67.2% of the induced voltages were classified as unipolar (Type I) and, except for one case, all of them had positive polarity. About 20.3% of the voltages were classified as Type II, whose waveshape is composed of two semicycles, the first one of positive polarity. About 9.4% of the recorded voltages were classified as Type III, whose waveshape is also composed of two semicycles, but the first one which a much shorter duration and lower magnitude. Only 3.1% were classified as Type IV, whose waveshape has three semicycles and the peak value occurs in the third one, which has negative polarity and the longest duration.

Analysis of Lightning-induced Voltages in Overhead Transmission Lines

In this work we study the coupling of lightning induced voltages in Overhead Transmission Lines .The study is led directly in the time domain with hold in account the effect of a finite conductivity of the soil. After discretization by the method so-called FDTD (Finite Difference Time Domain) of the lines equations excited by a lightning wave and the application in every node of the network in current and voltage, we deduct a equations system, of which the resolution permits us to deduct the induced electric quantities in every node of the network. In order to confirm our theoretical work, we present a set of applications that allows validating this study.

Analysis of Lightning-Induced Voltages on Overhead Lines Using a 2-D FDTD Method and Agrawal Coupling Model

In this paper, the lightning-generated electromagnetic fields over lossy ground produced by lightning strikes either to flat ground or to a tall tower are calculated using the 2-D finite-difference time-domain (FDTD) method. The resultant horizontal and vertical electric fields are used as forcing functions in the discretized Agrawal electromagnetic coupling equations for the calculation of induced voltages on overhead horizontal conductors without employing the Cooray-Rubinstein formula. Comparison of the results with those obtained using the 3-D FDTD method and with experimental data found in the literature is used to test the validity of the examined method. The approach employed here generally provides sufficient accuracy while allowing significant reduction in computation time and storage requirements as compared to the 3-D FDTD method. From the analysis carried out in this paper, induced voltages appear to be strongly dependent on ground conductivity, somewhat influenced by return-stroke speed, and essentially independent of return-stroke model [transmission-line (TL), modified transmission line with linear current decay with height (MTLL), or modified transmission line with exponential current decaywith height (MTLE)].

周波数領域における避雷器を考慮した誘導雷現象解析手法

周波数領域における避雷器を考慮した誘導雷現象解析手法

Analysis of lightning-induced voltages in a network of conductors using the ATP-EMTP program

The knowledge of the coupling mechanism between lightning electromagnetic fields and low power installations is of special interest in order to improve the protection of electrical equipment, such as computer networks, connected to the power grid against lightning-induced voltages. In this paper a modelling procedure that permits the use of the Alternative Transient Program to the Electro-Magnetic Transient Program (ATP-EMTP) in the calculation of lightning-induced voltages in low voltage power installations is outlined. The calculated results obtained through this procedure agree well with experimental results gathered in the field by exposing a network of conductors to lightning generated electromagnetic fields.

有限な大地導電率を考慮した多導体系配電の誘導雷現象解析

有限な大地導電率を考慮した多導体系配電の誘導雷現象解析

Analysis of lightning-induced voltages on overhead lines

Since the publication in 1967 of the author's original analysis on induced voltages on overhead lines by nearby lighting strokes, G. Cornfield (1972) and J.L. Jakubowski (1974) have made important suggestions to improve the analysis. The author examines these suggestions with the intent of implementing then where necessary. He has incorporated Cornfield's correction and concludes that Jakubowski's suggestion is incorrect.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>