A Comprehensive Framework for Direct Lightning-Structure-Human Interaction Modelling in Heritage Monuments and Safety Assessment

Abstract

Lightning is a perilous and unavoidable event of nature that presents major deleterious consequences on humans, tall structures, electrical power systems, forests, etc. Though several research studies have been carried out to analyse the sufficiency of a Lightning Protection System (LPS), very few research findings have been reported to assess the extent of risk due to lightning-human interaction in the vicinity of tall structures. This research aims at carrying out detailed modelling and simulation studies of LPS for heritage structure. Several current waveshapes as stipulated in IEC 62305 are modelled appropriately and presented to the electrical equivalent circuit representation of a heritage monument in South India (Brihadisvara Temple) to ascertain the impact of lightning parameters on heritage monuments. In addition, to assess the effectiveness of the earthing system, detailed earthing models during lightning is developed to assess the role played by aspects such as soil resistivity (single and double), earth electrode dimensions, nature of elements in the equivalent circuit, etc. Further, the role of lightning strikes on human due to step and touch potential is ascertained by formulating a lumped electrical equivalent model of human to assess its role and impact on dry and wet skin.

Studying Direct Lightning Stroke Impact on Human Safety Near HVTL Towers Considering Two Layer Soils and Ionization Influence

“…After calculating all the aforementioned parameters, the transient behavior of current passing through the human heart can be obtained by the use of ATP-EMTP [15]. The grounding fault current is 𝑖 𝑔 , which is discharged from the grounding system into the earth according to equation (9):…”

“…The effectiveness of the grounding system and complex earthing models during lightning are utilized to evaluate the role performed by aspects such as earth electrode dimensions, soil resistivity, and the equivalent circuit nature elements. Moreover, the role of lightning strikes on humans caused by touch and step potential is determined by devising a lumped electrical model of human to evaluate its role and influence on wet and dry skin [9].…”

“…Over the last few decades, various efforts have been made to define reference limits and do studies relating to the impacts of electric current on humans and animals. However, the majorities of these researches only look at power frequencies and are mostly concerned with the study of sinusoidal current with frequency in the range of 15-100 Hz, which ended in the preparation of international standards actually in the use [8][9][10][11]. Since there are no specified criteria for determining the maximum electric current, a human may suffer from lightning strokes.…”