Validation of the Approximate Time-Domain Method for the Lightning-Horizontal Electric Field at the Surface of Two-layer Earth by Using FDTD

• Published in: IEEE transactions on electromagnetic compatibility Vol. 56; no. 5; pp. 1121 - 1128
• Main Authors: Zhang, Qilin, Zhang, Liang, Hou, Wenhao, Su, Jianfeng
• Format: Journal Article
• Language: English
• Published: New York IEEE 01-10-2014; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Accuracy; Approximation; Channels; Earth; Electric fields; Finite difference methods; Finite difference time domain method; Frequency-domain analysis; Lightning; Lightning horizontal field; lightning return stroke; Mathematical analysis; Return strokes (lightning); stratified earth; Surface impedance; Time-domain analysis; two-dimensional finite-difference time domain (2-D FDTD)
• ISSN: 0018-9375; 1558-187X
• DOI: 10.1109/TEMC.2014.2309598

Based on the two-dimensional finite-difference time-domain (2-D FDTD) method, we have validated the time-domain method presented by Barbosa (B-P formula) for calculating the lightning-radiated horizontal electric field at the earth surface within distances from 30 to 1000 m from the lightning channel, considering the horizontally stratified earth. The results show that, except for distances in the vicinity of the lightning channel (e.g., 30 m), the B-P approximate formula can approximately predict the field peak value from 50 to 1000 m with a satisfactory accuracy within errors of 10% and its accuracy for subsequent return strokes seems to be more or less the same as that for first return strokes. The rise-time part of the field wave predicted by the B-P approximate formula is similar to that predicted by the 2-D FDTD, however, the tail of the wave predicted by the B-P approximation may be shorter than that by the 2-D FDTD (e.g., 30 and 50 m).