Turk J Elec Eng & Comp Sci (2016) 24: 4083 – 4097 c ⃝ T ¨ UB ˙ ITAK doi:10.3906/elk-1311-175 Turkish Journal of Electrical Engineering & Computer Sciences http://journals.tubitak.gov.tr/elektrik/ Research Article Determination of the striking distance of a lightning rod using finite element analysis Ab Halim ABU BAKAR 1, * , Alyaa ZAINAL ABIDIN 2 , Hazlee Azil ILLIAS 1,2 , Hazlie MOKHLIS 1,2 , Syahirah ABD HALIM 2 , Nor Hidayah NOR HASSAN 2 , Chia Kwang TAN 1 1 UM Power Energy Dedicated Advanced Centre (UMPEDAC), Wisma R&D University of Malaya, Kuala Lumpur, Malaysia 2 Department of Electrical Engineering, Faculty of Engineering, University of Malaya, Kuala Lumpur, Malaysia Received: 21.11.2013 • Accepted/Published Online: 08.07.2015 • Final Version: 20.06.2016 Abstract: The problems related to electromagnetic waves transmitted by lightning strikes can be studied through physical lightning models based on laboratory results. The main concern of these models is determining the striking distance between the leader tip and the lightning rod during lightning occurrences. The striking distance is a significant factor in designing the lightning protection system. However, models using finite element analysis (FEA) for this purpose are less likely to be found in the literature. Therefore, in this work, a geometry model of a lightning rod and leader was developed using available FEA software. The model was used to determine the striking distance for different lightning rod heights. The results obtained were compared with those of previous research using different methods to validate the models developed using FEA software. From the comparison, the striking distance obtained from the FEA software as a function of lightning rod height was in good agreement compared to other methods from previous research. The use of FEA software also enables the effect of different tip radii of curvature and shapes of the lightning rod on striking distance to be studied, which can further enhance our understanding of the relationship between striking distance and different rod parameters. Key words: Striking distance, finite element analysis, COMSOL 1. Introduction Modeling of lightning requires a large number of variables, which makes the analysis complex, including determination of striking distance [1]. The striking distance, r , is described as the gap between a lightning rod to be struck with the leader tip when the upward progressing leader is initiated from the lightning rod [2] as shown in Figure 1. The significance of striking distance is to estimate the lightning performance, which is mainly used in designing lightning protection of earthed structures. Mostly, the lightning protection system contains a lightning rod that will intercept the lightning flash and protect the structure from direct lightning strikes. Numerous models have been successfully developed in the past to determine the striking distance against the height of a lightning rod. These models were based on the physics of the streamer-to-leader transition and observations made in the laboratory on long sparks to determine leader inception from a grounded structure. The concept of striking distance described using the electrogeometrical model (EGM) is the distance between the tip of the downward leader and the grounded structure when the final jump is established. In this model, the presence of the connecting leader (connecting the upward and the downward leader) is neglected since * Correspondence: a.halim@um.edu.my 4083