Similarity Theory as a Tool in the Analysis of Lightning-Induced Transient Phenomena

Inhalt:
Similarity theory is a scientific method that has been successfully used in experimental analysis in various areas of technology for decades. The methodology of similarity theory can also be an aid in the analysis of lightning-induced processes, e.g. in the conversion of results from experiments on models to the original scale. In this paper, some basics of similarity theory are explained and scale laws for transient phenomena due to lightning strikes are established. When applied correctly, these laws enable the construction of experimental models in which phenomena like the original oc-cur. The application of the scale laws is demonstrated using examples of investigations of lightning-induced transient phenomena. As a result of the investigations, it is proposed to include a new informative annex on the application of scale laws in Edition 3 of IEC 61400-24 "Wind turbines - Part 24: Lightning protection" to support the design process of lightning protection systems for rotor blades.