Modeling the Attachment of Lightning Dart and Dart-Stepped Leaders to Grounded Objects
(English)In: IEEE transactions on electromagnetic compatibility (Print), ISSN 0018-9375, E-ISSN 1558-187XArticle in journal (Refereed) Accepted
Attachment of downward subsequent dart leadershas been recently proposed as a possible mechanism of lightningdamage of wind turbine blades. Since subsequent dart and dart-stepped leaders propagating after the first lightning discharge are one-to-two orders of magnitude faster than downward stepped leaders, the direct evaluation of the dart leader interception by upwardconnecting leaders from the turbine has not been attempted before. In this paper, the self-consistent leader inception and propagation model SLIM is used to evaluate the lightning attachmentprocess of subsequent dart leaders by accounting the rapid changingelectric fields produced by their fast descent toward the ground. For this, an improved evaluation of the charge per unit length requiredto thermalize the upward connecting leader is derived. The analysis considers upward connecting leaders propagating along the preheated channel of a prior discharge. Three study cases oflightning attachment of dart leaders and dart-stepped leader reported in rocket-triggered lightning experiments are evaluated. It is shown that reasonable predictions of the length, duration, andvelocity of positive upward connecting leaders can be obtainedwith SLIM in agreement with the experimental results. Furtherresearch on upward leader discharges necessary to improve themodeling of attachment of dart lightning leaders is discussed.
Place, publisher, year, edition, pages
Institute of Electrical and Electronics Engineers (IEEE).
lightning attachment, lightning dart and dart-stepped leaders, rocket-triggered lightning
Other Electrical Engineering, Electronic Engineering, Information Engineering
IdentifiersURN: urn:nbn:se:kth:diva-197275OAI: oai:DiVA.org:kth-197275DiVA: diva2:1050936
QC 201612012016-11-302016-11-302016-12-01Bibliographically approved