On the Striking Distance for the Design of Lightning Protection System for Substations in Selected Countries

Abstract

Since the dawn of civilization, humans have been fascinated by one of the most common natural occurrences called lightning. It’s not just a fascinating but also dangerous occurrence for electrical equipment. Substation, which is one of the most important parts of power transmission and distribution, is susceptible to lightning strikes. If lightning directly strikes a substation, it may cause huge damage to the equipment of the substation. Thus, a proper lightning protection system is required in order to protect the substation. Striking distance is one of the most important aspects of a substation’s lightning protection design. This study aims to analyze the striking distance range for Japan, Austria, Brazil, Sweden and the USA based on methodologies and recorded lightning current found in the literature. The values of lightning peak current and types of lightning protection systems (mast/wire) are considered in the calculation of striking distance for the selected countries. Among the countries studied, the USA has the greatest striking distance range, while Sweden has the smallest. It is also observed that the striking distance range is significantly higher when the lightning mast is used instead of shield wire as lightning protection device. In addition, this paper presents a graphical representation of the recommended striking distance range for the selected countries which will help the designer to efficiently design the lightning protection system of substations for those selected countries.