Investigation on the Sources of Reflection at the Junction of Tall Grounded Object and Lightning Channel

Raysaha, Rosy Balaram and Kumar, Udaya (2011) Investigation on the Sources of Reflection at the Junction of Tall Grounded Object and Lightning Channel. In: IEEE Transactions on Electromagnetic Compatibility, 53 (3). pp. 764-772.

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Abstract

During lightning strike to a tall grounded object (TGO), reflections of current waves are known to occur at either ends of the TGO. These reflection modify the channel current and hence, the lightning electromagnetic fields. This study aims to identify the possible contributing factors to reflection at a TGO-channel junction for the current waves ascending on the TGO. Possible sources of reflection identified are corona sheath and discontinuity of resistance and radius. For analyzing the contribution of corona sheath and discontinuity of resistance at the junction, a macroscopic physical model for the return stroke developed in our earlier work is employed. NEC-2D is used for assessing the contribution of abrupt change in radii at a TGO-channel junction. The wire-cage model adopted for the same is validated using laboratory experiments. Detailed investigation revealed the following. The main contributor for reflection at a TGO-channel junction is the difference between TGO and channel core radii. Also, the discontinuity of resistance at a TGO-channel junction can be of some relevance only for the first microsecond regime. Further, corona sheath does not play any significant role in the reflection.

Item Type:	Journal Article
Publication:	IEEE Transactions on Electromagnetic Compatibility
Publisher:	IEEE
Additional Information:	Copyright 2011 IEEE. Personal use of this material is permitted.However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE.
Keywords:	Abrupt change in radii;channel resistance;corona sheath; lightning strike to TGO;reflection at TGO-channel junction; wire-cage model in NEC-2D
Department/Centre:	Division of Electrical Sciences > Electrical Engineering
Date Deposited:	15 Sep 2011 11:02
Last Modified:	15 Sep 2011 11:02
URI:	http://eprints.iisc.ac.in/id/eprint/40452

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